# GCN_circulars

GRB_name: GRB080802A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8051
SUBJECT: GRB 080802: Swift detection of a probable burst
DATE:    08/08/02 15:46:43 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
M. M. Chester (PSU), C. B. Markwardt (CRESST/GSFC/UMD),
D. M. Palmer (LANL) and E. Troja (INAF-IASFPA) report on behalf of
the Swift Team:

At 15:12:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080802 (trigger=318832).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 270.748, -32.333 which is 
   RA(J2000) = 18h 02m 60s
   Dec(J2000) = -32d 19' 59"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 50 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 15:13:39.7 UT, 78 seconds
after the BAT trigger. Using promptly downlinked data we find a bright,
variable, uncatalogued X-ray source located at RA, Dec 270.72692,
-32.33395 which is equivalent to:
   RA(J2000)  = 18h 02m 54.46s
   Dec(J2000) = -32d 20' 02.2"
with an uncertainty of 3.1 arcseconds (radius, 90% containment). This is
1.1 arcminutes from the BAT position and within its error radius. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (2.75e+21
cm^-2, Kalberla et al. 2005), with an excess column of 2.3
(+2.63/-2.21) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 1.47e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 100 seconds with the White 
(160-650 nm) filter starting 86 seconds after the BAT trigger. No 
afterglow candidate is apparent in the initial data products. The 
2.7'x2.7' sub-image covers 25% of  the BAT error circle and 100% of 
the XRT error circle. The typical 3-sigma upper limit has been about 
 18.5 mag. The list of sources is typically complete to about 18 mag. 
 No  correction has been made for the expected extinction, which at
this location is large and uncertain. 

Because this source is near the Galactic center, this event may
be a local transient rather than a cosmological GRB.  However,
no known sources are found at the XRT position in either 
SIMBAD or NED. 

No BAT_POSITION notice was available due to a TDRSS hand-over
at the time of the burst. 


GRB_name: GRB080802A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8052
SUBJECT: GRB 080802, Swift-BAT refined analysis
DATE:    08/08/03 00:12:25 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

H. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+388 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080802 (trigger #318832)
(Baumgartner, et al., GCN Circ. 8051).  The BAT ground-calculated position is
RA, Dec = 270.729, -32.329 deg which is 
   RA(J2000)  =  18h 02m 55.0s 
   Dec(J2000) = -32d 19' 45.6" 
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows several overlapping peaks starting
at ~T-40 sec and ending at ~T+180.  T90 (15-350 keV) is 176 +- 50 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-31.1 to T+176.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.76 +- 0.19.  The fluence in the 15-150 keV band is 1.3 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-7.56 sec in the 15-150 keV band
is 0.3 +- 0.0 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 

Given the Galactic lon,lat being in the bulge, we can not rule out
a non-GRB source for this trigger.  All other factors point to a GRB.
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/318832/BA/


GRB_name: GRB080802A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8053
SUBJECT: GRB 080802: UVI Telescope Upper Limit
DATE:    08/08/03 01:17:11 GMT
FROM:    Adria C. Updike at Clemson U  <aupdike@clemson.edu>

Adria C. Updike (Clemson U), James Neff (College of Charleston), and
Dieter H. Hartmann (Clemson U) report:

We observed the field of GRB 080802 (GCN 8051, Baumgartner et al.) using
the 0.5m UVI (University of the Virgin Islands) telescope at St. Thomas
for 5 minutes in the R band, beginning 00:12 UT (~9 hours after the
trigger).  We detect no new sources within the XRT error circle to a
limiting magnitude of R ~ 18.5 as calibrated against the USNO B1.0
catalog.  Further observations we hampered by cloud cover.

This message may be cited.


GRB_name: GRB080802A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8054
SUBJECT: GRB 080802: Swift-XRT Refined Analysis
DATE:    08/08/03 03:20:34 GMT
FROM:    Michael Stroh at PSU/Swift  <stroh@astroh.org>

M.C. Stroh (PSU) reports on behalf of the Swift-XRT team:

We have analyzed the first two orbits of Swift-XRT data obtained for  
GRB 080802 (Baumgartner et al., GCN Circ. 8051), totaling 81s of  
Windowed Timing and 2.4ks of Photon Counting data.

The X-ray light-curve begins with a single flare that peaks to ~40 cts/ 
s near T+100 seconds. The rest of the light-curve can be fit by a  
single broken power-law with an initial decay index of 2.91 +/- 0.33,  
second decay index of -0.51 +/- 0.25 and a break near T+1000s. Since  
the second decay index indicates brightening, we cannot accurately  
predict counting rates at T+24 or T+48 hours.

The spectrum from the Windowed Timing data can be fit with a power-law  
in excess of the Galactic value (2.75e21 cm-2, Kalberla et al. 2005),  
with a column density of 4.8 (+2.0/-1.7)e21 cm^-2 and a photon index  
of 1.40 (+0.24/-0.22). The observed (unabsorbed) 0.3-10 keV flux is  
4.78e-10 (4.95e-10) ergs/cm^2/s.

This is an official product of the Swift-XRT team.


GRB_name: GRB080802A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8055
SUBJECT: GRB 080802: Swift/UVOT Upper Limits
DATE:    08/08/03 05:56:21 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) and W.H. Baumgartner (GSFC/UMBC) report on behalf of 
the Swift/UVOT team:

The Swift/UVOT observed the field of GRB 080802 starting 87 s after the 
BAT trigger (Baumgartner et al., GCN Circ. 8051).  We do not find a source 
in any of the UVOT observations inside the XRT error circle (Baumgartner 
et al., GCN Circ. 8051). The 3-sigma upper limits for detecting a source 
in the first white and v finding charts (FC) exposure and co-added frames 
are:

Filter          T_start T_stop  Exp     Mag (3-sigma UL)
                 (s)     (s)     (s)
=========================================================
white (FC)      87      186     100     > 20.0
white           4803    5002    200     > 20.4
v (FC)          193     406     213     > 18.7
v               5214    5413    200     > 18.7
b               4598    6189    356     > 20.1
u               4393    6028    400     > 19.9
uvw1            4188    5822    400     > 19.8
uvm2            3983    5618    400     > 19.7
uvw2            5009    5208    200     > 19.5

The values quoted above are not corrected for the expected Galactic 
extinction corresponding to a reddening of E(B-V) = 0.80 mag in the 
direction of the burst (Schlegel et al. 1998).


GRB_name: GRB080804A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8056
SUBJECT: GRB 080804: ROTSE-III Detection of Optical Counterpart
DATE:    08/08/04 23:28:02 GMT
FROM:    Wiphu Rujopakarn at U AZ/Steward  <wiphu@as.arizona.edu>

W. Rujopakarn (Steward), E.S. Rykoff (UCSB) report on behalf of the ROTSE
collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia,
responded to GRB 080804 (Swift trigger 319016). The first image was at
23:20:34.3 UT, 19.6 s after the burst (6.3 s after the GCN notice time).
The unfiltered images are calibrated relative to USNO A2.0. We detect a
17.2 magnitude, brightening source with coordinates:

     21:54:40.1      -53:11:03.8    (J2000), with positional uncertainty
of 1" or better

start UT     mag     mlim(of image)
----------------------------------
23:20:50.2     17.2     16.9


This source is not visible in DSS (second epoch), 2MASS or the MPChecker
database.

A jpeg image is available at
http://www.rotse.net/images/gsb319016_3c01_img.jpg Note that the object
marked 38 is the candidate in question.

Continuing observations are in progress.


GRB_name: GRB080804A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8057
SUBJECT: GRB 080804: Swift detection of a burst with optical afterglow
DATE:    08/08/04 23:37:27 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. L. Racusin (PSU), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), M. M. Chester (PSU),
N. Gehrels (NASA/GSFC), D. Grupe (PSU),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
C. Pagani (PSU), D. M. Palmer (LANL), M. C. Stroh (PSU) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 23:20:14 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080804 (trigger=319016).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 328.701, -53.195 which is 
   RA(J2000)  =  21h 54m 48s
   Dec(J2000) = -53d 11' 40"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows multiple overlapping
peaks with a duration of about 20 sec.  The peak count rate
was ~1500 counts/sec (15-350 keV), at ~3 sec after the trigger. 

The XRT began observing the field at 23:21:53.7 UT, 99.0 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 328.66583, -53.18532 which
is equivalent to:
   RA(J2000)  = 21h 54m 39.80s
   Dec(J2000) = -53d 11' 07.2"
with an uncertainty of 3.0 arcseconds (radius, 90% containment). This
location is 83 arcseconds from the BAT onboard position, within the BAT
error circle. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.63e+20 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 5.50e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of nominal 100 seconds with the White
(160-650 nm) filter starting 109 seconds after the BAT trigger. There is a
candidate afterglow in the list of sources generated on-board at
  RA(J2000)  =  21:54:40.2 = 328.6675
  DEC(J2000) = -53:11:05   = -53.18472
with a 1-sigma error radius of about 1.0 arc sec. The estimated white
magnitude is 16.8 with a 1-sigma error of about 0.5 mag. No correction
has been made for a Galactic extinction corresponding to a reddening of
0.02 mag along the line of sight. 

Burst Advocate for this burst is J. L. Racusin (racusin AT astro.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080804A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8058
SUBJECT: GRB 080804: UVES redshift
DATE:    08/08/05 03:21:55 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

Christina C. Thoene (DARK/NBI), Antonio de Ugarte Postigo (ESO),
PaulM. Vreeswijk, Daniele Malesani (DARK/NBI), Palli Jakobsson
(Univ. Hertfordshire) report on behalf of a larger collaboration:

We observed the afterglow of GRB 080804 (Racusin et al., GCN 8057;
Rujopakarn & Rykoff, GCN 8056) with the UVES high-resolution
spectrograph at the VLT. Observations started on 2008 Aug 5.008 UT (50
min after the GRB). We obtained two spectra with exposure times of 30
and 45 minutes. The spectra cover the wavelength range from 3500 to
9460 Angstroms.

We detect a strong DLA as well as a large range of absorption lines
including SiII, SII, OI, CII, AlII, MgI and SiII* from which we derive
a redshift of z=2.2045.

We acknowledge excellent support from the observing staff at Paranal,
including Swetlana Hubrig, Thomas Rivinius, and Yuri Belestky. We are
especially indebted to Swetlana Hubrig and Martin Netopil for using
part of their telescope time.


GRB_name: GRB080805A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8059
SUBJECT: GRB 080805: Swift detection of a burst
DATE:    08/08/05 08:13:07 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

C. Pagani (PSU), W. H. Baumgartner (GSFC/UMBC), M. M. Chester (PSU),
J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester),
D. Grupe (PSU), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), J. Mao (INAF-OAB),
A. Moretti (INAF-OAB), K. L. Page (U Leicester), D. M. Palmer (LANL),
J. L. Racusin (PSU), P. Romano (INAF-IASFPA) and
H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team:

At 07:41:34 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080805 (trigger=319036).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 314.231, -62.438 which is 
   RA(J2000) = 20h 56m 55s
   Dec(J2000) = -62d 26' 16"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a FRED-like
structure with a duration of about 50 sec.  The peak count rate
was ~2600 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 07:42:38.3 UT, 63.5 seconds after
the BAT trigger. Using promptly downlinked data we find a bright, fading
uncatalogued X-ray source located at RA, Dec 314.22273, -62.44433 which
is equivalent to:
   RA(J2000)  = 20h 56m 53.46s
   Dec(J2000) = -62d 26' 39.6"
with an uncertainty of 3.6 arcseconds (radius, 90% containment).  This position
is 26.6 arcseconds from the BAT position, within the BAT error circle. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
3.45e+20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 100 seconds with the White 
(160-650 nm)  filter starting 74 seconds after the BAT trigger. No 
afterglow candidate is apparent in the initial data products. The 
2.7'x2.7' sub-image covers 25% of  the BAT error circle and 100% of 
the XRT error circle. The typical 3-sigma upper limit has been about 
 18.5 mag. The list of sources is typically complete to about 18 mag. 
 No  correction has been made for the expected extinction
corresponding   to E(B-V) of 0.043. 

Burst Advocate for this burst is C. Pagani (pagani AT astro.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080805A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8060
SUBJECT: GRB 080805: GROND detection of possible afterglow
DATE:    08/08/05 08:42:10 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

T. Kruehler, F. Schrey, J. Greiner, C. Clemens, A. Yoldas (all MPE 
Garching),
A. Kupcu Yoldas (ESO) and G. Szokoly (Eoetvoes Univ., Budapest) report on
behalf of the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405), mounted at the 2.2m ESO/MPI 
telescope at La Silla Observatory (Chile), started observations of the 
field of GRB 080805 (Pagani et al. 2008, GCN #8059) in g'r'i'z'JHK at 
07:45 UT, 3.5 min after the burst. We detect an optical/NIR afterglow 
candidate in the XRT error circle (Pagani et al. 2008, GCN #8059) in 
griz at:

RA(J2000): 20h 56m 53.44
DEC(J2000): -62d 26' 39.8"

with uncertainties of 0.5".

We measure the following magnitudes, calibrated against USNO-B1 field stars:

g = 21.7 +- 0.2
r = 20.5 +- 0.1
i = 20.1 +- 0.1
z = 19.9 +- 0.1

No statement about fading can be made at the moment. If this is the
afterglow of GRB 080805, then its redshift is smaller than 3.5.


GRB_name: GRB080805A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8061
SUBJECT: GRB 080805: Afterglow confirmation
DATE:    08/08/05 11:17:52 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (ESO), D. Malesani, P. M. Vreeswijk,
J.P.U. Fynbo (DARK/NBI), P. Jakobsson (Univ. Hertfordshire),
A.O. Jaunsen (Univ. Oslo), J. Sollerman (DARK/NBI and Univ.
Stockholm), report:

We observed the field of GRB 080805 (Pagani et al., GCN 8059)
with the ESO VLT equipped with FORS2. We clearly identify the
candidate afterglow first reported by Kruehler et al. (GCN 8060).
From the first image, obtained at 07:50:49 UT (9.3 min after the
burst) to 10:00:05 UT (138.5 min after the burst) the object faded
by 2.0 magnitudes in the R band. We thus consider the afterglow
candidate to be secure.

We acknowledge excellent support from the observing staff at
Paranal, especially to Patricia Guajardo and Yuri Belestky.


GRB_name: GRB080805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8062
SUBJECT: GRB 080805: VLT redshift
DATE:    08/08/05 14:21:31 GMT
FROM:    Pall Jakobsson at U Hertfordshire  <P.Jakobsson@herts.ac.uk>

P. Jakobsson (U. Hertfordshire), P. M. Vreeswijk (DARK/NBI),
A. de Ugarte Postigo (ESO), D. Malesani, J. P. U. Fynbo (DARK/NBI)
and J. Sollerman (DARK/NBI; U. Stockholm) report on behalf of a
larger collaboration:

Using FORS2 on the ESO Very Large Telescope, we have obtained
low and medium resolution spectra (grisms 300V, 1200R and 1400V)
of the optical afterglow of GRB 080805 (Kruehler et al., GCN 8060;
de Ugarte Postigo et al., GCN 8061). The first spectrum was
taken approximately an hour after the burst.

A firm upper limit of z < 2.2 can be placed on the redshift
of GRB 080805 from the lack of Ly-alpha forest lines in the
spectrum of the afterglow. This is consistent with the GROND
observations (Kruehler et al).

The spectra display Fe II (2344,2382,2600) and the Mg II
doublet (2796,2803) in absorption corresponding to a redshift
of z = 1.20. There is also tentative evidence of an absorption
system at z = 1.50 (Fe II and Mg II), but further analysis is
required to confirm the reality of this system.

We thank the Paranal staff for excellent support, especially
Patricia Guajardo and Yuri Belestky.


GRB_name: GRB080805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8063
SUBJECT: GRB080805 optical limit by "Pi of the Sky"
DATE:    08/08/05 14:26:10 GMT
FROM:    Marcin Sokolowski at Soltan Inst. Nuc Studies,Warsaw  <msok@fuw.edu.pl>

M.Cwiok, W.Dominik, G.Kasprowicz, A.Majcher, A.Majczyna,
K.Malek, L.Mankiewicz, M.Molak, K.Nawrocki, L.W.Piotrowski,
D.Rybka, M.Sokolowski, J.Uzycki, G.Wrochna, A.F.Zarnecki
on behalf of "Pi of the Sky" collaboration http://grb.fuw.edu.pl

"Pi of the Sky" apparatus observed the position of GRB080805. Three 10s
images of this field have been taken at 07:37:45 - 07:38:42 ( 3 minutes
before the GRB). No new object is seen within the error box and the limit
is 12.5 magnitudo.

After receiving the trigger from SWIFT, the field was observed 84s after
the GRB. No new object has been found within the Swift-BAT error box.
The limiting magnitude (unfiltered) on single 10s exposures is :

         07:42:58 - 07:43:08 - 12.2 mag
         07:43:11 - 07:43:21 - 12.2 mag
         07:43:24 - 07:43:34 - 12.2 mag

  and 12.5 mag on 20 coadded images.


GRB_name: GRB080804A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8064
SUBJECT: GRB 080804: Faulkes Telescope South observations
DATE:    08/08/05 15:05:59 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi (INAF-OAB) and I. Steele (LJMU) on behalf of a
larger collaboration report:

On 2008 August 05 (12:44:12 UT) we began observing the field of GRB 080804
(Racusin et al. GCN Circ. 8057) with the Faulkes Telescope South using
the R filter.

In our coadded frame we detect the optical afterglow at the position
fully consistent with that reported by Swift-UVOT (Racusin et al. GCN
Circ. 8057) and slighly outside the error circle given by ROTSE-III
(Rujopakarn et al. GCN Circ. 8056) which is 1.5 arcsec away.

Telescope   Filter  T_mid[hr]   Exposure[s]      Mag
-----------------------------------------------------------
FTS         R        14.235       1200         21.6 +/- 0.1
-----------------------------------------------------------

The calibration was performed using the R2 magnitudes of several
USNOB-1 catalogue field objects. The uncertainty reported above does
not include the additional ~0.3 mag of the USNOB-1 catalogue.
From the comparison with the value reported by UVOT we infer an
average power-law decay index of ~0.7.


GRB_name: GRB080804A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8065
SUBJECT: GRB080804: Gemini South redshift confirmation
DATE:    08/08/05 15:34:42 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara@astro.psu.edu>

A. Cucchiara, D. B. Fox (Penn State), S. B. Cenko (Caltech) and E. Berger
(Harvard U.) report on behalf of a larger collaboration:

Starting at 01:27 UT on 2008 August 5 we observed  the optical counterpart
of GRB 080804 (Rujopakarn et al., GCN 8056, Racusin et al., GCN 8057) using
Gemini-South with GMOS spectrograph (R~1200).
We acquired 2x900s spectra which covered the wavelength range 4000A-8000A
and 2x900s spectra covering the range 6000A-10000A.

We detect some of the metal absorption features identified by Thoene et al.
(GCN 8058), like FeII (1608, 2260), NiII (1741 and 1751) and we also detect
MgII doublet (2796,2803). We also detect part of the red wing of the Lyman
break indicating a possible DLA associated with the grb host galaxy.

All these features confirm that the grb redshift is z = 2.20.

We thank the Gemini staff for conducting these observations.


GRB_name: GRB080804A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8066
SUBJECT: GRB 080804: Enhanced Swift-XRT position
DATE:    08/08/05 15:42:09 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 6979 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 080804, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 328.66755, -53.18483 which is equivalent
to:

RA (J2000): 21h 54m 40.21s
Dec (J2000): -53d 11' 05.4"

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB080804A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8067
SUBJECT: GRB 080804, Swift-BAT refined analysis
DATE:    08/08/05 15:54:46 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

C. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), K. McLean (GSFC/UMD), D. Palmer (LANL),
J. L. Racusin (PSU), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080804 (trigger #319016)
(Racusin, et al., GCN Circ. 8057).  The BAT ground-calculated position is
RA, Dec = 328.675, -53.189 deg which is 
   RA(J2000)  =  21h 54m 41.9s 
   Dec(J2000) = -53d 11' 20.2" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 19%.
 
The mask-weighted light curve shows the main peak starting at ~T-10sec,
peaking at ~T+2 sec, and ending at ~T+100 sec.  T90 (15-350 keV) is
34 +- 16 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.4 to T+62.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.19 +- 0.09.  The fluence in the 15-150 keV band is 3.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.57 sec in the 15-150 keV band
is 3.1 +- 0.4 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/319016/BA/


GRB_name: GRB080805A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8068
SUBJECT: GRB 080805, Swift-BAT refined analysis
DATE:    08/08/05 17:26:52 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

D. Palmer (LANL), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
C. Pagani (PSU), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+302 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080805 (trigger #319036)
(Pagani, et al., GCN Circ. 8059).  The BAT ground-calculated position is
RA, Dec = 314.231, -62.433 deg, which is 
   RA(J2000)  =  20h 56m 55.3s 
   Dec(J2000) = -62d 25' 58.8" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows a FRED-like peak starting at ~T-5sec,
peaking at ~T+3 sec, and ending at ~T+140 sec.  T90 (15-350 keV) is
78 +- 7 sec (estimated error including systematics).
 
The time-averaged spectrum from T-6.1 to T+93.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.53 +- 0.07.  The fluence in the 15-150 keV band is 2.5 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+2.62 sec in the 15-150 keV band
is 1.1 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/319036/BA/


GRB_name: GRB080804A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8069
SUBJECT: GRB 080804: Swift/UVOT Refined Analysis
DATE:    08/08/05 18:29:58 GMT
FROM:    Paul Kuin at MSSL  <npkuin@googlemail.com>

N. P. M. Kuin (MSSL/UCL), and J. L. Racusin (PSU), report
on behalf of the Swift UVOT team

The Swift UltraViolet/Optical Telescope (UVOT) began observations
of GRB 080804, on August 4, 2008, at  23:21:45 UT, 91 seconds after
the initial Swift BAT trigger (Racusin et al., GCN Circ. 8057), and
started the finding chart exposure in the white filter at 111
seconds after the trigger.

The refined uvot position of GRB080804 is RA=0328.66750 Dec=-53.18461
deg.(= 21:54:40.2 -53:11:04.6), with an accuracy of 0.4", consistent
with the positions reported in GCN Circ. 8056 (Rujokaparn et al.),
8057 (Racusin et al.) and 8066 (Beardmore et al.).

The magnitudes with 1-sigma errors for GRB080804 are given below
for the initial observation sequence.

Filter Tstart(s) Tstop(s) Exp(s) Magnitude

wh      111        210     98.2    16.83 +/- 0.03
wh      711        720      9.6    18.3  +/- 0.16
v       217        616    393.5    17.17 +/- 0.05
v       752        771     19.4    17.85 +/- 0.30
uvm2    623        642     19.5   >17.6  (3 sigma UL)
uvw1    648        667     19.4   >18.2  (3 sigma UL)
b       697        706      9.6    18.1  +/- 0.27
u       672        691     19.4    17.4  +/- 0.17
uvw2    727        746     19.5   >18.2  (3 sigma UL)

uvw1    648       7442    529.3    20.9  +/- 0.4
uvm2    623       7237    529.4   >20.8  (3 sigma UL)
uvw2    727       6827   1179.5   >21.8  (3 sigma UL)

The upper limits in uvw2, uvm2, and weak detection in uvw1 are
consistent with the reported redshift of z=2.2045 by Thoene
et al. (GCN Circ. 8058).

The values quoted above are on the UVOT Photometric System
(Poole et al, 2008, MNRAS 383,627). They are not corrected for the
expected galactic reddening of E(B-V) = 0.016 in the direction of
the burst (Schlegel et al. 1998).


GRB_name: GRB080804A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8070
SUBJECT: GRB 080804: Swift-XRT Refined Analysis
DATE:    08/08/05 20:24:05 GMT
FROM:    Judith Racusin at PSU  <racusin@astro.psu.edu>

J. Racusin, C. Pagani (PSU) report on behalf of the Swift-XRT team:

We have analysed the first five orbits of Swift-XRT data available for GRB 
080804 (Racusin et al., GCN 8057) consisting of 123 s of WT mode data, and 
11.0 ks of PC mode data.  The enhanced XRT position is given in Beardmore 
et al. (GCN Circ. 8066).

The preliminary 0.3-10.0 keV lightcurve can be fit with a single power-law 
with a decay index of 1.09+/-0.03.

The WT and PC spectra can be jointly fit with an absorbed power-law with a 
photon index of 1.6 +/- 0.2.  The intrinsic absorption is at a level of 
1.7e21 cm^-2 (using z=2.2045, Thoene et al., GCN Circ. 8058), in addition 
to the Galactic absorption along the line of sight (1.6e20 cm^-2, Kalberla 
et al. 2005).  The average observed (unabsorbed) flux is 2.5e-10 (2.6e-10) 
ergs cm^-2 s^-1 and 1.2e-11 (1.2e-11) ergs cm^-2 s^-1, for the WT and PC 
spectra respectively.

Assuming the X-ray emission continues to decline at the same rate, we 
predict a 0.3-10.0 keV XRT count rate of 0.008 counts/s at T+24hr, which 
corresponds to an observed flux of 3.4e-13 ergs cm^-2 s^-1.

This Circular is an official product of the Swift-XRT team.


GRB_name: GRB080805A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8071
SUBJECT: GRB 080805: Swift/UVOT Upper Limits
DATE:    08/08/05 22:48:54 GMT
FROM:    Paul Ward at MSSL  <paw@mssl.ucl.ac.uk>

P. Ward (MSSL-UCL) and C. Pagani (PSU) report on behalf of
the Swift/UVOT team:

The Swift/UVOT observed the field of GRB 080805 starting 74 s after the 
BAT trigger (Pagani et al., GCN Circ. 8059).  We do not find a source in 
any of the UVOT observations inside the XRT error circle or at the 
position reported by Kruehler et al. (GCN 8060). The 3-sigma upper limits 
for detecting a source are:

Filter   T_start T_stop   Exp   Mag

White    76      175      98.5  > 20.70
White    5473    18024    1082  > 22.12
v        182     6083     332   > 19.81
b        5268    17112    1082  > 21.43
u        5061    5260     197   > 20.11
uvw1     4856    5055     197   > 19.99
uvm2     4650    6267     371   > 20.09
uvw2     5680    18053    219   > 20.12

The values quoted above are in the UVOT photometric system
(Poole et al. 2008, MNRAS, 383, 627). No correction has been
made for the expected extinction corresponding to E(B-V) of
0.043 mag in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB080805A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8072
SUBJECT: GRB 080805: Swift-XRT Refined Analysis
DATE:    08/08/06 03:27:50 GMT
FROM:    Claudio Pagani at PSU/Swift-XRT  <pagani@astro.psu.edu>

C. Pagani, J. Racusin and D. Grupe (PSU) report on behalf of the Swift-XRT team:

We have analysed the first four orbits of Swift-XRT data for GRB 080805 (Pagani
et al., GCN 8059) beginning at T0+71 s until T0+23.1 ks.

Using 728 s of XRT Photon Counting mode data and 2 UVOT images, we find an
astrometrically corrected X-ray position (using the XRT-UVOT alignment and
matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 314.22312,
-62.44479 which is equivalent to:

RA (J2000):  20 56 53.55
Dec (J2000): -62 26 41.2

with an uncertainty of 2.6 arcsec (radius, 90% confidence).

The XRT lightcurve shows an initial flare and a steep decay followed by a
shallower phase. The decaying lightcurve can be fit with a broken power-law
with an initial decay index of 3.5+/-0.3, a break at approximately T0+500
seconds and a later decay index of 0.9+/-0.3.

The spectrum of the Windowed Timing mode data from the first orbit can be fit by
an absorbed power-law with a photon index of 1.3+/-0.1 and absorption consistent
with the Galactic value along the line of sight (3.5e20 cm^-2, Kalberla et al.
2005).  The average observed (unabsorbed) flux of the WT mode data is 1.7e-9
(1.9e-10) ergs cm^-2 s^-1.

Assuming the X-ray emission continues to decline at the same rate, we predict a
0.3-10.0 keV XRT count rate of 0.003 counts/s at T+24hr, which corresponds to
an observed flux of 1.5e-13 ergs cm^-2 s^-1.

This Circular is an official product of the Swift-XRT team.


GRB_name: GRB080804A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8073
SUBJECT: GRB 080804: ATCA Radio Observations
DATE:    08/08/06 03:36:41 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

A.J. van der Horst (NASA/ORAU) and C. Kouveliotou (NASA/MSFC) report:

"We observed the position of the GRB 080804 afterglow at 4.8 and 8.6 GHz
with the Australia Telescope Compact Array at August 5 16.92 UT to 22.45
UT, i.e. 0.73 - 0.96 days after the burst (GCN 8057).
We do not detect a radio source at the position of the optical afterglow
(GCN 8056). The formal flux measurement for a point source at the location
of the optical counterpart is -41 +/- 64 microJy at 4.8 GHz, and 40 +/- 63
microJy at 8.6 GHz.

We would like to thank the staff of the Australia Telescope National
Facility, in particular Angel Lopez-Sanchez and Philip Edwards, for
scheduling and obtaining these Target of Opportunity observations."


GRB_name: GRB080727B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8074
SUBJECT: GRB 080727B: Late VLT imaging
DATE:    08/08/06 05:38:15 GMT
FROM:    Thomas Kruehler at MPE/MPI  <kruehler@mpe.mpg.de>

T. Kruehler, J. Greiner (MPE Garching) and S. Klose (Tautenburg) report:

We triggered VLT/FORS imaging of the field of the Swift GRB 080727B
(Immler et al. 2008, GCN #8022). A series of exposures were obtained in
Rc (6*120s), Bessel I (5*120s) and Gunn z (4*120s) starting from 06:19 UT
on 2008-07-29, roughly 46 hours after the burst. We marginally detect the
optical afterglow (Li et al, 2008, GCN #8024) in the stacked I and z
frames at 24.7 +- 0.3 mag (I) and 23.9 +- 0.5 mag (z), calibrated
against USNO-B1 stars.

Given the large errors and the uncertain and high foreground extinction,
this is consistent with the power law reported in Kruehler et al (2008,
GCN #8045) and puts the upper redshift limit to ~5. The 3 sigma upper
limit in Rc (>25.5 mag) is above that power law and does not constrain
the shape of the spectral energy distribution or the redshift.

We thank the ESO/VLT staff for the perfect support.


GRB_name: GRB080804A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8075
SUBJECT: GRB 080804: GROND observations
DATE:    08/08/06 07:58:12 GMT
FROM:    Thomas Kruehler at MPE/MPI  <kruehler@mpe.mpg.de>

T. Kruehler, F. Schrey, J. Greiner, A. Yoldas, C. Clemens, S. McBreen 
(all MPE Garching),
A. Kupcu Yoldas (ESO) and G. Szokoly (Eoetvoes Univ., Budapest) report on
behalf of the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405), mounted at the 2.2m ESO/MPI
telescope at La Silla Observatory (Chile), started observations of the
field of GRB 080804 (Racusin et al. 2008, GCN #8057) in g'r'i'z'JHK at
23:26 UT, 16 min after the burst. We clearly detect the optical
afterglow (Rujopakarn & Rykoff 2008, GCN #8056) in all filters at a
position consistent with UVOT (Racusin et al. 2008, GCN #8057) and the
Faulkes Telescope South (Guidorzi & Steele, GCN #8064). Observations
continued for 65 min and were resumed at 06:30 UT for 30 min.

Assuming the USNO-B1 star at RA(J2000)=328.6627, DEC(J2000)=-53.18288
having R2=18.08 mag, we measure the following r' magnitudes, not
corrected for the expected Galactic foreground extinction corresponding
to a reddening of E_(B-V)=0.02 (Schlegel et al. 1998):

Filter T_mid    Exposure     Brightness
          (s)         (s)               (mag)
-----------------------------------------
r'      1160       67        18.09 +- 0.03
r'      1565       67        18.37 +- 0.03
r'      1996       115       18.66 +- 0.02
r'      2768       115       18.96 +- 0.02
r'      3672       375       19.25 +- 0.02
r'      26112     375       21.02 +- 0.04


The reported magnitudes are a subset of the complete observation
consisting of 24 individual frames. The total r band light curve is well
fitted by power law with index of 0.87 +- 0.03 between 0.32 h and 7.63 h
post burst. This decline is consistent with the Faulkes Telescope South
detection (Guidorzi & Steele, GCN #8064) at 14.235 h post burst.

Assuming the optical light curve continues the decline with the same 
power law index, we predict r' band magnitudes of 22.7 at 2 days and 
23.4 at 4 days post burst.

The broad band SED from g' to K can be fitted by a power law with index
0.8 +- 0.1 (statistical) +-0.1 (systematic), where the latter is due to 
the lack of photometric calibration.


GRB_name: GRB080805A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8076
SUBJECT: GRB 080805: Faulkes Telescope South optical observations
DATE:    08/08/06 20:03:48 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi (INAF-OAB), I. Steele and R.J. Smith (LJMU) on behalf of a
larger collaboration report:

On 2008 August 05 (10:12:35 UT) we began observing the field of GRB 080805
(Pagani et al. GCN Circ. 8059) with the Faulkes Telescope South using
the R and i' filters.

In our coadded i' frame we marginally detect the optical afterglow
(Kruehler et al. GCN Circ. 8060; de Ugarte Postigo et al. GCN Circ. 8061):

Telescope   Filter  T_mid[hr]   Exposure[s]      Mag
-----------------------------------------------------------
FTS         i'         5.410       6x300       22.5 +/- 0.4
-----------------------------------------------------------

The calibration was performed using the I magnitudes of several
USNOB-1 catalogue field objects.
From the comparison with the value reported by GROND
(Kruehler et al. GCN Circ. 8060) we estimate an average
power-law decay index of ~0.7, consistent with that inferred
in the R band (de Ugarte Postigo et al. GCN Circ. 8061).


GRB_name: GRB080805A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8077
SUBJECT: GRB 080805: VLT redshift update
DATE:    08/08/08 18:23:14 GMT
FROM:    Pall Jakobsson at U Hertfordshire  <P.Jakobsson@herts.ac.uk>

P. Jakobsson (U. Hertfordshire), J. P. U. Fynbo, P. M. Vreeswijk
(DARK/NBI) and A. de Ugarte Postigo (ESO) report on behalf of a
larger collaboration:

We have reduced the VLT spectra presented in Jakobsson et al.
(GCN 8062) with new calibration files and performed a thorough
line search in all four grisms (300V, 1028z, 1200R, 1400V)
covering approximately 3700-9500 A. We confirm the existence
of a line system at redshift z = 1.505 +/- 0.001 displaying
Fe II (2382,2586,2600), the Mg II doublet (2796,2803) and
Mg I (2852). In addition, there is a clear bump (flux decrease)
present between 5300-5600 A that can be interpreted as the
2175 A extinction feature at z ~ 1.5.

Apart from the z = 1.20 redshift system presented in GCN 8062,
no other significant lines are visible. We therefore conclude
that z = 1.505 is the redshift of GRB 080805.


GRB_name: GRB080723B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8078
SUBJECT: GRB 080723B: XMM-Newton observation
DATE:    08/08/08 20:16:55 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

G. Sala, J. Greiner, S. McBreen, T. Kruehler, P.M. Esquej (all MPE Garching, 
Germany) report:


XMM-Newton observed GRB 080723B detected by INTEGRAL (Gotz et al. 2008, 
#GCN 8002) and AGILE (Del Monte et al. 2008, GCN #8003), starting at
18:47:41 UT, on July 23, 2008, for an exposure of 62.5 ks (Schartel 2008, 
GCN 8005). The observation was affected by background radiation flaring, 
reducing the good exposure time to 54 ks. 
GRB 080723B is detected with an average count rate of 0.9, 0.3 and 0.01 cts/s 
in the EPIC-pn, MOS1/2 and RGS instruments, respectively. Here we report
on a refined position and the X-ray spectrum of the afterglow of GRB 080723B.

By identifying four X-ray sources in the FOV of the EPIC camera with 
counterparts from the 2MASS catalogue, we are able to register the X-ray
coordinate system, and obtain a best-fit  X-ray position of the afterglow
of GRB 080723B of RA = 176.83317, Decl. = -60.24096, equivalent to

RA  (2000.0) =  11 47 20.09
Dec (2000.0) = -60 14 28.6
  
with an uncertainty of 2.0 arcsec. This coincides perfectly with the X-ray 
position reported by Swift/XRT (Page 2008, GCN #8008), but reduces the
error circle by nearly a factor of two.
  
The X-ray flux during the XMM-Newton observation decays gradually, with no
noticable deviations from a power law of slope 1.50 +/-0.05, compatible
within the error with the flatter Swift/XRT decay (Page 2008, GCN #8009).
The spectrum averaged over the full observation (25.7 - 65.7 ks after the
GRB trigger) can be fitted by an absorbed power-law with photon index 
Gamma = 1.79 +/-0.02, and an equivalent hydrogen column of 
1.22(+/-0.02)*10^22 cm^-2, in excess of the catalogued Galactic column 
in this direction, 7.4*10^21 cm^-2 (Kalberla et al. 2005, AA 440, 775; 
Dickey & Lockman 1990, ARAA 28, 215).  Being at a Galactic latitude of 
1.6 deg, this difference may be due to clumpiness of foreground material 
relative to the spacing of the above HI surveys, rather than necessarily 
due to intrinsic extinction in the GRB host galaxy. The observed 0.3-10 keV 
flux during the XMM-Newton observation decreases from about 
1*10^-11 erg/cm^2/s (26 ks after burst trigger) to  
2.5*10^-12 erg/cm^2/s (65 ks post-burst). 

We thank Ignacio de la Calle, Nora Loiseau and Norbert Schartel from the 
XMM-Newton SOC (Villafranca, Spain) for scheduling and executing this 
observation.


GRB_name: GRB080723B
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8079
SUBJECT: GRB 080723B: GROND upper limits
DATE:    08/08/08 20:19:08 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

T. Kruehler, J. Greiner, F. Schrey, G. Sala, C. Clemens (all MPE Garching) 
report on behalf of the GROND team:

We observed the field of the INTEGRAL GRB 080723B (Gotz et al. 2008, 
GCN #8002) on two epochs, simultaneously in g'r'i'z'JHK with GROND 
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m ESO/MPI telescope 
at La Silla Observatory (Chile). First observations started at 
2008-07-24 23:46 UT, 36.4 h after the burst, with total exposures of 
50 min in g'r'i'z' and 40 min in JHK. A second set of images was obtained 
starting at 2008-07-31 23:39 UT with effective exposures of 100 min 
(g'r'i'z') and 80 min (JHK).

We do not detect a fading source in neither the XRT (Page 2008, GCN #8008) 
nor XMM (Sala et al. 2008, GCN #8078) error circle down to limiting 
magnitudes of:

g' > 23.4
r' > 23.6
i' > 22.7 
z' > 22.7
J > 20.6
H > 19.5
K > 18.5

calibrated against USNO-B1 and 2MASS field stars. At longer wavelength,
these limits are compromised by the high density of foreground stars.

The reported upper limits are not corrected for the expected Galactic 
foreground extinction corresponding to a reddening of E_(B-V) = 1.3 
(Schlegel et al. 1998).


GRB_name: GRB080810A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8080
SUBJECT: GRB 080810: Swift detection of a burst with a bright optical afterglow
DATE:    08/08/10 13:31:39 GMT
FROM:    David Burrows at PSU/Swift  <dxb15@psu.edu>

K. L. Page (U Leicester), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
P. A. Evans (U Leicester), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
N. P. M. Kuin (MSSL), J. Mao (INAF-OAB), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU),
R. L. C. Starling (U Leicester) and T. N. Ukwatta (GSFC/GWU) report
on behalf of the Swift Team:

At 13:10:12 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080810 (trigger=319584).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 356.779, +0.320 which is 
   RA(J2000) = 23h 47m 07s
   Dec(J2000) = +00d 19' 11"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multiple-peaked
structure with a duration of about 140 sec, including a peak during the
time of the XRT/UVOT observations.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~22 sec after the trigger. 

The XRT began observing the field at 13:11:28.3 UT, 76.0 seconds after
the BAT trigger. XRT found a bright, flaring, uncatalogued X-ray source 
located at RA, Dec 356.7936, +0.3188 which is equivalent to:
  RA(J2000)  = 23h 47m 10.4s
  Dec(J2000) = +00d 19' 07.6"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 52 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

UVOT took a finding chart exposure of nominal 100 seconds with the White
(160-650 nm) filter starting 88 seconds after the BAT trigger. There is a
bright candidate afterglow in the list of sources generated on-board at
  RA(J2000)  =  23:47:10.5 = 356.79375
  DEC(J2000) = +00:19:10   =  +0.31944
with a 1-sigma error radius of about 1.0 arc sec. The estimated white
magnitude is 14.7 with a 1-sigma error of about 0.5 mag. No correction
has been made for a Galactic extinction corresponding to a reddening of
0.03 mag along the line of sight. 

We note the presence of the galaxy J234710.47+001906.0 
about 1.7 arcsec from the XRT position. 

Burst Advocate for this burst is K. L. Page (kpa AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8081
SUBJECT: GRB 080810 : optical observation with KANATA
DATE:    08/08/10 13:51:42 GMT
FROM:    Akira Arai at Hiroshima U  <arai-akira@hiroshima-u.ac.jp>

Y. Ikejiri, M. Uemura, T. Ohsugi, K. Kawabata, A. Arai, M. Yamanaka, and K. Sakimoto (Hiroshima Univ.), 
report on behalf of the KANATA GRB team:

  We performed optical-NIR observations of the field of 
GRB 080810 (GCN Circ. 8080) with TRISPEC attached to 
the "KANATA" 1.5-m telescope.  

  We confirmed a very bright, fading object at the position of the optical 
afterglow detected with UVOT.  
Our preliminary results are below:

time(UT)       mag.              exposure_time
Aug. 2008                        (sec)
10.553258      13.7  $B!^(B 0.1  V  33sec * 1

Comparison star: 
23:46:58.51 +00:18:30.2 V=14.07 (NOMAD)
 
Further observation and analysis are ongoing.


GRB_name: GRB080810A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8082
SUBJECT: GRB 080810, Swift-BAT refined analysis
DATE:    08/08/10 16:20:08 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
K. L. Page (U Leicester), D. Palmer (LANL), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+381 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080810 (trigger #319584)
(Page, et al., GCN Circ. 8080).  The BAT ground-calculated position is
RA, Dec = 356.783, 0.310 deg which is 
   RA(J2000)  =  23h 47m 08.0s 
   Dec(J2000) = +00d 18' 35.1" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 68%.
 
The mask-weighted light curve shows a cluster of overlapping peaks starting
at ~T-20, the tallest at T+25 sec, and ending at ~T+120 sec.
T90 (15-350 keV) is 106 +- 5 sec (estimated error including systematics).
 
The time-averaged spectrum from T-21.2 to T+111.4 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.34 +- 0.06.  The fluence in the 15-150 keV band is 4.6 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+24.68 sec in the 15-150 keV band
is 2.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/319584/BA/


GRB_name: GRB080810A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8083
SUBJECT: GRB 080810: Keck/HIRES Spectroscopy 
DATE:    08/08/10 17:51:26 GMT
FROM:    Jason Prochaska at UCO/Lick Obs  <xavier@ucolick.org>

J.X. Prochaska (UCSC), D. Perley (UCB),
A. Howard (UCB), H.-W. Chen (Chicago),
G. Marcy (UCB), D. Fischer (SFSU), and
C. Wilburn (Keck) report on behalf of GRAASP:

"We observed the afterglow of GRB 080810 with the Keck/HIRES
echelle spectrometer for a series of 1000s exposures starting
at UT 13:47:50 under good conditions.  A quick analysis of the
2D images reveals a Lyman limit system at ~3975Ang.
We tentatively associate this feature with the host galaxy
of GRB 080810 and estimate a redshift z_GRB = 3.35.

Further analysis is in progress."

This GCN may be cited.


GRB_name: GRB080810A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8084
SUBJECT: GRB 080810: ROTSE-III Prompt Detection of Optical Counterpart 
DATE:    08/08/10 18:29:37 GMT
FROM:    Eli Rykoff at UCSB  <erykoff@physics.ucsb.edu>

E.S. Rykoff (UCSB), reports on behalf of the ROTSE collaboration:

ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded
to GRB 080810 (Swift trigger 319584, GCN 8080, Page et al.). The first
image was at 13:10:47.6 UT, 35.3 s after the burst (21.6 s after the
GCN notice time), contemporaneous with the gamma-ray emission (GCN
8082, Sakamoto et al.).  We took 10 5s exposures, 10 20s exposures,
and 137 60s exposures under variable conditions.  The unfiltered
images are calibrated relative to USNO B1.0. We detect a 12.8
magnitude, variable source with coordinates:

   23:47:10.5 +00:19:11.5 (J2000) (uncertainty of 1" or better)

start UT        mag     mlim(of image)
----------------------------------

13:11:16.7     12.8     16.5

The position is consistent with the XRT and UVOT positions reported in
GCN 8080.

Our prompt detection shows the afterglow initially rising from 13.7
mag (38s post-burst) to a peak of 12.8 mag (67s post-burst).  This is
followed by a shallow decay from ~67s to ~230s (decay index
alpha=-0.15+/-0.05), and a break to a steeper decay from ~230s to
~6000s post-burst (decay index alpha=-1.13+/-0.02).  Preliminary
analysis does not show any significant deviations from this smooth
evolution.

A jpeg image is available at
http://www.rotse.net/images/gsb319584_3a02_img.jpg
The object in question is marked with yellow and blue circles.


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8085
SUBJECT: GRB 080810: KANATA optical-NIR observation, update
DATE:    08/08/10 19:35:44 GMT
FROM:    Makoto Uemura at Hiroshima U  <uemuram@hiroshima-u.ac.jp>

M. Uemura, M. Yamanaka, Y. Ikejiri, K. Sakimoto, T. Ohsugi, 
K.S. Kawabata, and A. Arai, report on behalf of the KANATA GRB team:

  We continue the observation of GRB 080810 with the KANATA 1.5-m 
telescope.  We obtained V, J, and Ks-band images of the field 
of the afterglow using TRISPEC.
The latest observation shows:

time(UT)    mag.   err   exposure time
Aug. 2008  
10.78444   18.92V  0.05   123sec * 10
10.78479   17.53J  0.31    72sec * 10

The light curve we obtained can be described with a simple 
power-law decay between 420 and 20000 sec after the GRB trigger, 
without an apparent break.  
The power-law index is calculated to be 1.21+/-0.02. 
The index is slightly, but significantly larger than that reported 
in GCN 8084, implying a possible break around the very early 
or very late phase of our observation period.  

Further monitoring is encouraged.


GRB_name: GRB080810A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8086
SUBJECT: GRB 080810: Enhanced Swift-XRT position
DATE:    08/08/10 22:50:44 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1614 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 080810, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 356.79418, +0.32000 which is equivalent
to:

RA (J2000): 23h 47m 10.60s
Dec (J2000): +00d 19' 12.0"

with an uncertainty of 1.4 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB080810A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8087
SUBJECT: GRB 080810: Swift-XRT Team refined analysis 
DATE:    08/08/10 23:53:16 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team:

We have analysed the first four orbits of the XRT data obtained for GRB 
080810 (Page et al., GCN Circ. 8080). The first orbit (376 s) was taken 
entirely in Windowed Timing (WT) mode, followed by 2.8 of Photon Counting 
(PC) data. The UVOT-enhanced position was given by Evans et al. in GCN 
Circ. 8086.

The WT data show a number of flares, with the strongest peaking around 107 
and 209 s after the trigger; the first of these is also visible in the BAT 
data. The PC data in later orbits can be modelled with a single power-law 
decay, with alpha = 1.20 +0.12/-0.11.

There is strong spectral evolution throughout the first orbit, as is 
typical for flaring activity. A spectrum extracted from the PC mode data 
(3.8-12.1 ks after the trigger) can be fitted with a power-law of Gamma = 
1.98 +/- 0.06, absorbed by the Galactic column in this direction of 
3.28x10^20 cm^-2. The observed (unabsorbed) flux over this time is 1.99 
(2.20) x 10^-11 erg cm^-2 s^-1.

If the decay continues with alpha = 1.2, the predicted count-rate at 24 
hours is 0.02 count s^-1, corresponding to an observed (unabsorbed) flux 
of 8.5 (9.4) x 10^-13 erg cm^-2 s^-1.

This is an official product of the Swift-XRT team.


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8088
SUBJECT: GRB 080810: RTT150 optical observations
DATE:    08/08/11 06:49:28 GMT
FROM:    Rodion Burenin at IKI, Moscow  <rodion@hea.iki.rssi.ru>

R. Burenin (IKI), I. Khamitov (TUG), A. Galeev, I. Bikmaev, 
N. Sakhibullin (KSU/AST), M. Pavlinsky, R. Sunyaev (IKI),
Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)


We observed the GRB 080810 afterglow with Russian-Turkish 1.5-m telescope
(RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey). We made a set
of exposures in BVRI between 8.3 and 12.6 hours after the burst. During our
observations the OT faded from 19.1 to 19.5 in R (USNO-B1.0 calibrated).

We also obtained a set of low resolution spectra using TFOSC
spectrometer. We detected Ly and other absorption lines and confirm the
redshift z=3.35 measured by Prochaska et al. (GCN 8083). Further analysis is
ongoing.


GRB_name: GRB080810A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8089
SUBJECT: GRB 080810: Observations from NOT
DATE:    08/08/11 07:15:29 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (ESO), C.C. Thoene, J.P.U. Fynbo,
J. Hjorth (DARK/NBI), P. Jakobsson (U. Hertfordshire),
Z. Banhidi (NOT, IAC), F. Grundahl, T. Arentoft (U. of Aarhus)
report on behalf of a larger collaboration:

We have observed the afterglow of GRB 080810 (Page et al.
GCN 8080) from the Nordic Optical Telescope (NOT, Roque de los
Muchachos Observatory, La Palma, Spain) using ALFOSC. The
observations started on 10.9899 Aug (10.59 hours after the burst),
when we measure an R-band magnitude of 19.1+/-0.2 (based on
USNO-1B photometry). This  value is in agreement with the slope
decay measured by Rykoff (GCN 8084) implying that no break has
been produced between both observations. This is also consistent
with the magnitudes reported by Burenin et al. (GCN 8088). We
obtained the following coordinates for the afterglow (J2000+/-0.5"):
R.A.: 23:47:10.51
Dec.: +00:19:11.3
This value is slightly off from the value provided by UVOT (Page et
al. GCN 8080) but fully consistent with the one given by Rykoff
(GCN 8084).

We also obtained spectroscopic observations of the afterglow, where
we clearly detect Ly-alpha absorption, a flux drop blueward of the
Lyman break as well as other absorption  lines, including the CIV/CIV
doublet at a redshift of z~3.35, in agreement to what was reported by
Prochaska et al. (GCN 8083) and Burenin et al. (GCN 8088).


GRB_name: GRB080810A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8090
SUBJECT: GRB 080810: OSN follow-up
DATE:    08/08/11 08:12:32 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (ESO), F. Aceituno, A.J. Castro-Tirado
(IAA-CSIC) report on behalf of a larger collaboration:

We have observed the field of GRB 080810 (Page et al.
GCN 8080) with the 1.5m OSN telescope at Sierra Nevada
Observatory (Granada, Spain), covering the range between
11.93 and 15.11 hours after the burst in B, V, R and I bands.
We observe a continuous decay following a slope of
alpha = -1.11+/-0.02, consistent with the slope provided by
Rykoff et al. (GCN 8084). Preliminary analysis shows the
following magnitudes in an intermediate epoch as compared
to reference stars derived from the SDSS.

t-t0(h)  Filter      Mag
 13.82     B     21.4 +/- 0.3
 13.62     V     20.2 +/- 0.2
 13.85     R     19.5 +/- 0.2
 13.25     I     19.2 +/- 0.2


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8091
SUBJECT: GRB 080810: Kanazawa optical observation
DATE:    08/08/11 08:16:50 GMT
FROM:    Daisuke Yonetoku at Kanazawa U  <gcn@astro.s.kanazawa-u.ac.jp>

Y.Okuma, H.Fujimoto, T.Nashimoto, A.Wada, D.Yonetoku, T. Murakami, 
report on behalf of the Kanazawa GRB team:

We have imaged the field of GRB 080810 (Page et al. GCN 8080)
in R-band with 0.4m telescope at Kanazawa Japan.
We obtained the first image at one and half hours after 
the Swift trigger. We confirmed the bright optical counter 
part reported by Page et al. (GCN 8080), Ikejiri et al. (GCN 8081), 
and so on. Compared with the USNO-A2.0 catalog, the source 
magnitude is determined about 16.5 +/- 0.2 mag with 30 seconds 
exposure time from the begining of this observation.
Further analysis is in progress.


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8092
SUBJECT: GRB 080810: D50 optical observation
DATE:    08/08/11 10:14:35 GMT
FROM:    Matus Kocka at Monteboo Obs,Masaryk U,Brno  <koci@astronom.sk>

M. Kocka (kocka@sunkl.asu.cas.cz), M. Nekola, J. Strobl, R. Hudec, C. 
Polasek (AsU CAS - Ondrejov),
M. Jelinek, P. Kubanek (IAA-CSIC - Granada),
F. Munz (IASF/INAF - Bologna)

The 0.5m D50 telescope in the Ondrejov Observatory of the Astronomical 
Institute of the Academy of Sciences of the Czech Republic, observed GRB 
080810.Observation started at 22:26:41 UT (~9.4 hours after SWIFT 
detection).

After 80x20 sec exposure we detected optical counterpart at the coordinates:
23:47:10.5 +00:19:11.5 (J2000)(E.S. Rykoff GCN 8084)
Calibrated to near USNO-B1.0 catalog star

with the following results:
    time(UT) mid of exp     mag.   err   exposure time
    22:39:02        19.6    0.5    80x20 sec


image: http://zeus.asu.cas.cz/~koci/grb080810/GRB080810.jpg

    D50 telescope is controled by RTS2 software.

    Further analysis is in progress

    This message may be cited.


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8093
SUBJECT: GRB 080810: Liverpool Telescope observations
DATE:    08/08/11 10:14:52 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi (INAF-OAB), I. Steele (LJMU), N. Tanvir (U. Leicester)
on behalf of a larger collaboration report:

On 2008 August 11 (03:53:56 UT) we began observing the field of GRB 080810
(Page et al. GCN Circ. 8080) with the Liverpool Telescope using
the r' and i' filters.

The optical afterglow is clearly detected at the position reported
by ROTSE-III (Rykoff GCN Circ. 8084) and the NOT (de Ugarte Postigo
et al. GCN Circ. 8089). We found the following magnitudes:

Telescope   Filter  T_mid[hr]   Exposure[s]      Mag
-------------------------------------------------------------
LT          i'        14.770       300         19.14 +/- 0.04
LT          r'        15.328       300         19.93 +/- 0.04
-------------------------------------------------------------

The calibration was performed using the R2 and I magnitudes
of the following nearby USNOB1 catalogue star: 23:47:06.819,
+00:19:27.15, using R2=15.31, I=14.69.


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8094
SUBJECT: GRB 080810: optical observations
DATE:    08/08/11 10:23:24 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

M. Andreev,  (Terskol Branch of Institute of Astronomy), Ju. Babina (CrAO), 
V. Petkov, A. Kurenya (BNO INR RAS), A. Pozanenko (IKI) on behalf of larger 
GRB follow up collaboration  report:

We observed the afterglow  of GRB080810 (Page  et al. GCN 8080) with 
Zeiss-600 of  Mt.Terskol observatory in R-band on Aug. 11.  The  afterglow 
is detected in a combined image in a position consistent with coordinates 
reported by Rykoff  (GCN 8084). A photometry of the OT against USNO-B1.0 
stars is following:

T0+       Exposure  R_mag
(mid)

0.45598 d  8x180 s   19.4 +/- 0.2 


GRB_name: GRB080810A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8095
SUBJECT: GRB 080810: Swift/UVOT Refined Analysis
DATE:    08/08/11 17:31:57 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) & K. L. Page (U Leicester) report on
behalf of the Swift/UVOT team:

      The Swift/UVOT observed the field of GRB 080810 starting 65 s
after the BAT trigger (Page et al., GCNC. 8080).  Settled observations
started at T + 85 s.  We detect the optical afterglow (Page et al.,
GCNC 8080) in the v, b, and white filters at the UVOT-enhanced
location of the XRT afterglow (Evans et al., 2008, GCNC 8086).  The
refined UVOT source position is

 RA (J2000) =  23:47:10.48
Dec (J2000) = +00:19:11.3

with an estimated uncertainty of +/-0.6 arcsec (radius, 90%
confidence).  This is consistent with the positions of the optical
afterglow reported by Rykoff (GCNC 8084) and de Ugarte Postigo (GCNC
8089)

    Magnitudes and upper limits are reported below.

Filter     T_start (s) T_stop  Exposure      Mag  Err  Comment
white           85        185        98     14.63 0.07
   v            191        459       264     14.06 0.06
   b           4432       4632       197     17.85 0.08
   u           4227     68,686       727    >21.4       3-sigma UL
  uvw1         4022     68,283      3099    >22.3       3-sigma UL
  uvm2         3817     62,540      3229    >22.2       3-sigma UL
  uvw2         4843     50,866      1510    >22.0       3-sigma UL

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.03 mag (Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383,627).  The
non-detections in the u, uvw1, uvm2, and uvw2 filters are consistent
with a redshift of z = 3.35 (Prochaska, GCNC 8083).  The power-law
decay index in the b band between 4532 and 27,387 s is -1.29 +/- 0.22.

[GCN OPS NOTE(10sep08): Per author's request, the RA value
was changed from 23:47:10.26" to "23:47:10.48".]


GRB_name: GRB080810A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8097
SUBJECT: GRB080810: MITSuME optical observation
DATE:    08/08/12 09:27:10 GMT
FROM:    Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida@oao.nao.ac.jp>

M. Yoshida, K. Yanagisawa, D. Kuroda, Y. Shimizu, S. Nagayama,
H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf
of the MITSuME collaboration:

We observed the optical afterglow (Ikejiri et al. GCN 8081;
Rykoff GCN 8084) of GRB 080810 (Page et al. GCN 8080) with the
optical three color (g', Rc and Ic) imager attached to the
MITSuME 50cm telescope of Okayama Astrophysical Observatory.
Photometric results are listed below. We used USNO-B1.0 stars
for flux calibration.

Mid-UT      exp-T          g'            Rc            Ic
--------------------------------------------------------------
2008-08
10.60244   300 sec   17.16+/-0.06  16.70+/-0.04  15.69+/-0.05
--------------------------------------------------------------


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8098
SUBJECT: GRB 080810: RTT150 optical observations
DATE:    08/08/12 14:03:36 GMT
FROM:    Irek Khamitov at TUG  <irekk@tug.tug.tubitak.gov.tr>

A. Galeev (KSU/AST), I. Khamitov (TUG),
I. Bikmaev, N. Sakhibullin (KSU/AST),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)

report:

We observed the GRB 080810 afterglow with Russian-Turkish 1.5-m telescope
(RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey).

The serie of 600 sec (Ic), 600 sec (Rc), 900 sec (V) exposures was made
by using TFOSC  instrument under moderate seeing, starting at 12 Aug 2008,
01:19 UT, i.e. 36.16 hours after the burst.

The OT is clearly detected on all images. Using USNO-B1.0 stars
we estimate an Rc magnitude of 20.66+/-0.03 (~36.4 hours after the burst).
Using our earlier observations (Burenin et al., GCN8088)
the calculated power law index is -0.91+/-0.09 for decay
from ~8.3 h to ~36.4 h.


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GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8099
SUBJECT: GRB 080810: Liverpool and Faulkes North observations
DATE:    08/08/12 15:32:08 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi (INAF-OAB), D. Bersier (LJMU) and N. Tanvir (U. Leicester)
report on behalf of a larger collaboration:

We observed GRB 080810 (Page et al. GCN Circ. 8080) with the 2 m Liverpool
and Faulkes North telescopes starting on August 11 (23:34:09 UT) and
12 (13:14:49 UT), respectively, with r' and i' filters.
We clearly detect the afterglow with the following magnitudes:

Telescope   Filter  T_mid[hr]   Exposure[s]      Mag
-------------------------------------------------------------
LT          i'        34.657       6x300       20.01  0.06
LT          r'        39.525       6x300       20.78  0.05
FTN         i'        48.367       5x300       20.38  0.04
-------------------------------------------------------------

The calibration was performed using nearby USNOB1 stars as described
in our previous report (Guidorzi et al. GCN Circ. 8093).
Combining with our previous observation, we derive a power-law index
of 0.94  0.05 from 15 to 48 hr post burst, thus confirming the
flattening of the optical decay, in agreement with Galeev et al.
(GCN Circ. 8098).


GRB_name: GRB080810A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8100
SUBJECT: GLAST Burst Monitor detection of GRB 080810
DATE:    08/08/12 21:02:21 GMT
FROM:    Charles Meegan at NASA/MSFC  <charles.a.meegan@nasa.gov>

C.A. Meegan (NASA/MSFC), J. Greiner (MPE), N.P. Bhat (UAH), E. Bissaldi 
(MPE), M.S. Briggs (UAH), V. Connaughton (UAH), R. Diehl (MPE), G.J. 
Fishman (NASA/MSFC), L. Gibby (NASA/MSFC), A.S. Hoover (LANL), A.J. 
van der Horst (NASA/ORAU), A. von Kienlin (MPE), R.M. Kippen (LANL), C. 
Kouveliotou (NASA/MSFC), G.G. Lichti (MPE), S. McBreen (MPE), W.S. 
Paciesas (UAH), R.D. Preece (UAH), H. Steinle (MPE), M.S. Wallace
(LANL), 
and C.A. Wilson-Hodge (NASA/MSFC)report:

"At 13:10:12 UT on 10 August 2008, the GLAST Burst Monitor (GBM) 
triggered and located GRB 080810 (GBM 080810.549, trigger 240066613), 
which was also detected by Swift (Page et al., GCN 8080). 
The on-ground calculated location, using the GBM trigger data, is
RA, Dec 357.18, -4.61 which is equivalent to
    RA(J2000) = 23h 49m
    Dec(J2000) = -4d 37'
with an uncertainty of 5.0 degrees (radius, 1-sigma containment, 
statistical only). The angle from the Large Area Telescope (LAT) 
boresight is 61 degrees.

The GBM light curve shows a slow rise starting at T0-20, followed by 
a main emission phase comprising 5 pulses, a quiescent period and a 
sixth pulse at T0+102 s. 

The time-averaged spectrum from T-0.5 to T+53.1 sec is best fit by a 
power law function with an exponential high energy cutoff. The cutoff 
energy is 313.5 +/-73.6 keV and the power law index is -0.91 +/-0.12, 
with a reduced chi-square of 1.1 for 226 degrees of freedom. 

The fluence in the 50-300 keV band is (6.9 +/- 0.5) x 10^-6 erg/cm2. 
The 1-sec photon flux measured from T+23.5 sec in the 50-300 keV band 
is 1.85 +/- 0.16 ph/cm2/sec. All the quoted errors are at the 90% 
confidence level." 


GRB_name: GRB080810A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8101
SUBJECT: GRB 080810: Konus-Wind and Swift/BAT joint spectral analysis
DATE:    08/08/12 21:24:11 GMT
FROM:    Takanori Sakamoto at NASA/GSFC  <takanori@milkyway.gsfc.nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), 
W. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), 
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), 
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), 
D. Palmer (LANL), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), 
J. Tueller (GSFC), and T. Ukwatta (GWU) 
on behalf of the Swift-BAT team:  

V. Pal'shin, S. Golenetskii, R.Aptekar, E. Mazets, D. Frederiks, and
T. Cline on behalf of the Konus-Wind team, 

Report:

We performed the Konus-Wind and the Swift/BAT joint spectral analysis 
of GRB 080810 (Swift/BAT trigger #319584; Page et al., GCN Circ. 8080).  
Since the Konus-Wind observed this GRB in the waiting mode, we only 
have 3 channel spectral data for the Konus-Wind.  However, the 
Konus-Wind data covers the energy range from 20 keV to 1 MeV.  Therefore, 
the joint spectral analysis of the Konus-Wind and the Swift/BAT data 
enables to derive the broad-band spectral parameters of this burst.  

The time interval of the spectral data for each instrument is chosen from 
T0(BAT)-18.6 to T0(BAT)+60.8 sec where T0(BAT) is the trigger time of BAT 
at 13:10:12.3 UTC.  This time interval includes most of the burst emission, 
but not the last pulse around T0(BAT)+~100 sec which is clearly visible in 
the BAT data (Sakamoto et al., GCN Circ. 8082).  The energy ranges which we 
used in the joint spectral analysis are 20-1000 keV and 14-150 keV for 
the Konus-Wind and the Swift/BAT respectively.  The spectral data of two 
instruments are fit with the spectral model multiplied by the constant factor 
to take into account the systematic uncertainties in the response matrices 
of each instrument.

The spectrum is well fit with a power-law with exponential cutoff model 
(dN/dE ~ E^{alpha} * exp(-(2+alpha)*E/Epeak)).  The constant factors of each 
instrument agree within 20%.  No systematic residual from the best fit model 
is seen in the spectral data of each instrument.  The best fit spectral 
parameters are: alpha = -1.2 +- 0.1 and Epeak = 550 (-230/+860) keV 
(chi2/dof = 41/58).  The best fit spectral parameters for the Band function 
fixing beta=-2.5 are: alpha = -1.2 +- 0.1 and Epeak = 580 (-260/+850) keV 
(chi2/dof = 41/58).  The energy fluence in the 15-1000 keV band calculated 
by a power-law with exponential cutoff model for this 79.5 sec interval is 1.7 
(-0.2/+0.1) x 10^-5 erg/cm2 (assuming the constant factor of the BAT is fixed to 1).  

Assuming z = 3.35 (Prochaska et al., GCN Circ. 8083; Burenin et al., 
GCN Circ. 8088) and a standard cosmology model with H_0 = 71 km/s/Mpc, 
Omega_M = 0.27, Omega_Lambda = 0.73, the isotropic energy release is 
E_iso ~5 x 10^53 erg in 1 keV to 10 MeV at the GRB rest frame extrapolating 
the best fit model spectrum.  

All the quoted errors are at the 90% confidence level.


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8102
SUBJECT: GRB 080810: RTT150 optical observations
DATE:    08/08/13 13:46:42 GMT
FROM:    Irek Khamitov at TUG  <irekk@tug.tug.tubitak.gov.tr>

A. Galeev (KSU/AST), I. Khamitov (TUG),
I. Bikmaev, N. Sakhibullin (KSU/AST),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)

report:

We observed the GRB 080810 afterglow (Page et al. GCN Circ. 8080)
with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK
National Observatory, Turkey).

The series of several exposures in V,Rc,Ic bands were made
by using Andor CCD starting at 13 Aug 2008, 00:24 UT, i.e. ~ 59.23 hours 
after the burst.

Using USNO-B1.0 stars we estimate an Rc magnitude of 21.60+/-0.05
(~59.85 hours after the burst).

This measurement deviates from the power law decay with index -0.9
(Galeev et al., GCN8098,Guidorzi et al, GCN8099), that indicates steeper 
fading of OT after 48h.

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GRB_name: GRB080810A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8103
SUBJECT: Radio detection of GRB 080810 with the VLA
DATE:    08/08/13 17:57:01 GMT
FROM:    Poonam Chandra at U Virginia/NRAO  <pc8s@virginia.edu>

P. Chandra (UVA/NRAO) and  D. A. Frail (NRAO) report on behalf of the
Caltech-NRAO-Carnegie GRB Collaboration:

"We observed the field centered at the UVOT position of the Swift burst
GRB 080810 (GCN 8080) using the Very Large Array (VLA) at a frequency
of 8.46 GHz and starting at 2008 Aug 13.36 UT. We detect the radio flux
at the GRB afterglow position  with the flux density of 151  50 uJy.


The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."


GRB_name: GRB080812A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8104
SUBJECT: GLAST Burst Monitor detection of GRB 080812
DATE:    08/08/13 22:33:01 GMT
FROM:    Michael S. Briggs at UAH and MSFC  <michael.briggs@nasa.gov>

Michael Briggs (UAH) and Alexander van der Horst (NASA/ORAU) report on
behalf of the GLAST Burst Monitor Team:

"At  21:19:33 UT on 2008 Aug 12, the GLAST Burst Monitor (GBM)
triggered and located GRB 080812 (trigger 240268774 / 080812.889).
The on-ground calculated location, using the GBM trigger data, is
RA = 174.3, Dec = -41.3 (J2000 degrees)
(equivalent to J2000 11h 37m, -41d 18'),
with an uncertainty of 2.8 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is
currently estimated to be 2 to 3 degrees). The angle from the Large Area
Telescope (LAT) boresight is 71 degrees.

This GRB was about 15 s long with several peaks.  The time-averaged
spectrum from T-3.072 to T+14.336 s is best fit with a Comptonized
spectrum (power law times exponential cutoff).   The power law index is
+0.17 +/- 0.27 and the cutoff energy, parameterized as Epeak,
is 140 +/- 14 keV."


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8105
SUBJECT: GRB080810: optical observations
DATE:    08/08/16 02:20:14 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

V. Rumyantsev, Yu. Efimov (CrAO), A. Pozanenko (IKI) report on behalf of
larger GRB  follow-up collaboration:

We observed the optical afterglow of  GRB080810  (Page  et al., GCN  8080)
in R-band on Aug.10 between (UT) 23:17:05 - 23:48:32 with AZT-8 telescope of
CrAO. The afterglow is detect in a separate images in coordinates RA(J2000)
=  23 47 10.4, Dec(J2000) = +00 19 11.0 with uncertainty 0.5". The
coordinates are consistent with  reported early (Page et al. GCN 8080,
Rykoff GCN 8084, A. de Ugarte Postigo  et al. GCN 8090).
Based on  USNO-B1.0 star RA (J2000) = 23 47 11.12, Dec. (J2000) = +00 16
38.30, R=16.30 we estimated brightness of  the optical afterglow:

T0+,         Exposure,     R_mag,   err
(mid time)

0.4331 d  15x120 s     19.20  +/- 0.05


GRB_name: GRB080810A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8106
SUBJECT: GRB080810 - optical observations
DATE:    08/08/16 21:42:53 GMT
FROM:    Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr  <cthoene@astro.ku.dk>

Christina C. Thoene (DARK/NBI), Antonio de Ugarte Postigo (ESO) and
Christine Liebig (ARI Heidelberg) report:

We observed the field of GRB 080810 (Page et al. GCN 8080) with the Danish
1.54m telescope on La Silla/Chile on August 15.40 UT and 16.31 UT (4.85
and 5.76 days after the burst onset). We detect the decaying afterglow at
preliminary R-band magnitudes of 22.8+/-0.3 and 23.2+/-0.5.

Using the R band and unfiltered magnitudes published in GCNs (Rykoff et
al. GCN 8084, Burenin et al. GCN 8088, de Ugarte Postigo et al. GCN 8089 &
8090, Okuma et al. GCN 8091, Kocka et al. GCN 8092, Guidorzi et al. GCN
8093 & 8099, Andreev et al. GCN 8094, Yoshida et al. GCN 8097, Galeev et
al. GCN 8098 & 8102, Rumyantsev et al. GCN 8105) together with the data of
our own observations we find that the light curve can be described by a
powerlaw of index alpha = 1.12 +/- 0.02 between 400s and 1 day after the
burst. After 1 day there is a flux excess that can be seen both in the
optical and X-ray light curves (explaining the flattening measured by
Galeev et al., GCN8098 and Guidorzi et al., GCN8099), after which the
light curve begins to decay more steeply with an index in the optical of
alpha = 1.8 +/- 0.3.

Hail, thunderstorm and heavy rain currently prevent further observations
from the DK 1.54m.

C. Thoene and C. Liebig acknowledge the excellent cheese fondue at the
Swiss telescope yesterday evening.


GRB_name: GRB080816A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8107
SUBJECT: GLAST Burst Monitor detection of GRB080816
DATE:    08/08/19 12:09:51 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

Andreas von Kienlin, Sheila McBreen and Elisabetta Bissaldi (MPE) 
report on behalf of the GLAST Burst Monitor Team: 

"At 12:04:18 UT on 2008 Aug 16, the GLAST Burst Monitor (GBM) 
triggered and located GRB 080816 (GBM 080816.503 / trigger 240581059). 
The on-ground calculated location, using the GBM trigger data, is 
RA = 156.9, Dec = +54.60 (J2000 degrees) 
(equivalent to J2000 10h 28m, +54d 36'), 
with an uncertainty of 2.3 degrees (radius, 1-sigma containment, statistical 
only; there is additionally a systematic error which is currently estimated 
to be 2 to 3 degrees). The angle from the Large Area Telescope (LAT) 
boresight is 55 degrees at ~T+35 sec. 

This GRB has a duration of approximately 70 s and contains 4 peaks. 
The preliminary averaged time spectrum in the 10 keV to 500 keV energy band
from T-1 to T+69 s is well fit by a power law function with an exponential 
high energy cutoff. The power law index is -0.57 +/-0.14 and the cutoff 
energy, parameterized as Epeak, is 146.7 +/-14.5 keV, with a reduced 
chi-square of 1.2 for 291 degrees of freedom. 

The fluence in the 50-300 keV band is (1.86 +/- 0.20) x 10^-5 erg/cm2. 
The 1-sec photon flux measured from T+35 sec in the 50-300 keV band 
is  3.48 +/-0.66  ph/cm2/sec. All the quoted errors are at the 90% 
confidence level.
These spectral analysis results presented above are preliminary; the final 
results will be published in the GBM GRB Catalog." 


GRB_name: GRB080817A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8108
SUBJECT: GLAST Burst Monitor detection of GRB 080817 
DATE:    08/08/20 12:53:00 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

Elisabetta Bissaldi (MPE), Michael Briggs (UAH),
Andreas von Kienlin and Sheila McBreen (MPE)
report on behalf of the GLAST Burst Monitor Team:


"At 03:52:10 UT on 2008 Aug 17, the GLAST Burst Monitor (GBM)
triggered and located GRB 080817 (GBM 080817.161 / trigger 240637931).
The on-ground calculated location, using the GBM trigger data, is
RA = 151.29, Dec = -19.26 (J2000 degrees)
(equivalent to J2000 10h 05m, -19d 15' ),
with an uncertainty of 1 degree (radius, 1-sigma containment,
statistical only; there is additionally a systematic error
which is currently estimated to be 2 to 3 degrees).
The angle from the Large Area Telescope (LAT)
boresight is 80 degrees.

This GRB has a duration of approximately ~70 s and 
contains 2 main peaks in the interval between 0 and 25 s 
and a weaker peak around 50 s.

Spectral analysis is in progress."


GRB_name: GRB080817B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8109
SUBJECT: GLAST Burst Monitor detection of GRB080817B
DATE:    08/08/20 21:48:28 GMT
FROM:    Michael S. Briggs at UAH and MSFC  <michael.briggs@nasa.gov>

M.S. Briggs (UAH), A.J. van der Horst (NASA/ORAU), report on behalf of 
the GLAST Burst Monitor Team:

"At 17:17:07 UT on 2008 August 17, the GLAST Burst Monitor (GBM)
triggered and located GRB 080817B (trigger 240686228 / 080817.720).

The on-ground calculated location is RA= 72.9, Dec= -11.8 (J2000 degrees)
(equivalent to J2000 04h 51m, -11d 48') with an uncertainty of 7.5 degrees
(radius, 1-sigma containment, statistical only; there is additionally a
systematic error which is currently estimated to be 2 to 3 degrees). The
angle from the Large Area Telescope (LAT) boresight is 68 degrees.

This GRB was about 6 s long with 3 peaks.  Preliminary spectral results
are that the spectrum of the main peak, from T-0.955 to T+1.723 s
is best fit with a power-law with index -1.07 +/- 0.04.  The fluence of 
the event is 2.6E-6 ergs per square cm from 25 to 1000 keV."


GRB_name: GRB080818A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8110
SUBJECT: GLAST Burst Monitor detection of GRB 080818
DATE:    08/08/21 16:22:54 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

Elisabetta Bissaldi, Sheila McBreen (MPE),
Valerie Connaughton (UAH) and Andreas von Kienlin (MPE) 
report on behalf of the GLAST Burst Monitor Team: 

"At 13:54:24 UT on 2008 Aug 18, the GLAST Burst Monitor (GBM)
triggered and located GRB 080818 (GBM 080818.579 / trigger 240760465).

The on-ground calculated location, using the GBM trigger data, is
RA = 55.2, Dec = -5.0 (J2000 degrees) 
(equivalent to J2000 03h 41m, -05d 00') 
with an uncertainty of 8.3 degrees (radius, 1-sigma containment, 
statistical only; there is additionally a systematic error 
which is currently estimated to be 2 to 3 degrees). 
The angle from the Large Area Telescope (LAT) boresight is 68 degrees.

This GRB has a duration of approximately 50 s and contains 2 peaks.
The time averaged spectrum from 10 to 300 keV is well fitted by 
a power-law with index -1.57 +/- 0.05. The fluence of the event is 
2.26E-6 ergs per square cm from 50 to 300 keV.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB080816B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8111
SUBJECT: GLAST Burst Monitor detection of a GRB: 080816B
DATE:    08/08/21 22:31:00 GMT
FROM:    Rob Preece at UAH  <Rob.Preece@nasa.gov>

R. D. Preece (UAHuntsville) and A.J. van der Horst (NASA/ORAU) report  
on behalf of the GLAST Burst Monitor Team:

"At 23:44:01 UT on 16 August, 2008, the GLAST Burst Monitor (GBM)
triggered and located GRB 080816B (trigger 240623035 / 080816.989).
The on-ground calculated location, using the GBM trigger data, is
RA = 288.5, Dec = -6.5 (J2000 degrees)
(equivalent to J2000 19h 14m, -06d 30'),
with an uncertainty of 5.2 degrees (radius, 1-sigma containment,  
statistical only; there is additionally a systematic error which is  
currently estimated to be 2 to 3 degrees). The angle from the Large  
Area Telescope (LAT) boresight is 70 degrees.

This GRB was about 5 s long with 2 peaks, showing structure on the 64  
ms time scale. The time-averaged spectrum from T-3.584 to T+1.536 s,  
in the energy range 6 keV to 3500 keV, is best fit with a power law  
times exponential cutoff. The power law index is -0.37 +/- 0.17 and  
the cutoff energy, parameterized as Epeak, is 1230 +/- 230 keV. We  
note that this is a hard event. The average photon flux is 1.38 +/-  
0.08 ph/s-cm^2 in the energy interval 25 - 1000 keV.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."


GRB_name: GRB080822A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8112
SUBJECT: GRB 080822: Swift detection of a short burst
DATE:    08/08/22 13:08:50 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. T. Holland (CRESST/USRA/GSFC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
O. Godet (U Leicester), C. Guidorzi (INAF-OAB), J. A. Kennea (PSU),
V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
J. P. Osborne (U Leicester), C. Pagani (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL), M. Perri (ASDC),
T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-IASFPA),
R. L. C. Starling (U Leicester), G. Stratta (ASDC) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 12:41:59 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080822 (trigger=321174).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 75.270, +45.272 which is 
   RA(J2000)  =  05h 01m 05s
   Dec(J2000) = +45d 16' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single spike
with a duration of less than 128 msec.  The peak count rate
was ~10000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 12:43:16.3 UT, 77.1 seconds after
the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued
X-ray source with an enhanced position: RA, Dec 75.27800, 45.27623
which is equivalent to:
   RA(J2000)  = 05h 01m 6.72s
   Dec(J2000) = +45d 16' 34.4"
with an uncertainty of 2.6 arcseconds (radius, 90% containment). This
location is 25 arcseconds from the BAT onboard position, within the BAT
error circle. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (5.22e+21
cm^-2, Kalberla et al. 2005), with an excess column of 3.6
(+3.64/-2.95) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 100 seconds with the White  
(160-650 nm)  filter starting 83 seconds after the BAT trigger. No  
afterglow candidate is apparent in the initial data products.  The  
TDRSS source list covers 100% of   the XRT error circle. The list
of sources is typically complete to about 18 mag.  No  correction
has been made for the expected extinction corresponding to E(B-V)
= 1.29 mag. 

We note that the XRT position is 10.8 arcsec from the catalog position
of the ROSAT source 2RXP J050107.7+451637. 

Burst Advocate for this burst is S. T. Holland (sholland AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080822A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8113
SUBJECT: New Soft Gamma Repeater 0501+4516 was GRB 080822
DATE:    08/08/22 13:30:44 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC),
N. Gehrels (NASA/GSFC), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
J. Mao (INAF-OAB), F. E. Marshall (NASA/GSFC), C. Pagani (PSU),
D. M. Palmer (LANL), M. Perri (ASDC), T. Sakamoto (NASA/UMBC),
T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the
Swift Team:

At 13:12:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located a second outburst from a new SGR source 0501+4516 (trigger=321177)
which was previously reported as GRB 080822 (Holland et al, GCN Circ 8112). 
Swift was already looking at this location from the trigger on this source
of ~30 min earlier.  The BAT on-board calculated location is 
RA, Dec 75.265, +45.272, which is 
   RA(J2000)  =  05h 01m 04s
   Dec(J2000) = +45d 16' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single spike
with a duration of less than 128 msec.  The peak count rate
was ~17000 counts/sec (15-350 keV), at ~0 sec after the trigger. 


GRB_name: GRB080822A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8114
SUBJECT: GRB 080822 (SGR 0501+4516): archival optical observations
DATE:    08/08/22 17:49:29 GMT
FROM:    Denis Denissenko at IKI, Moscow  <denis@hea.iki.rssi.ru>

D. V. Denisenko (Space Research Institute, Moscow, Russia) reports:

Analysis of the Palomar Observatory Sky Survey plates available at
http://archive.stsci.edu/cgi-bin/dss_plate_finder has revealed a
variable object at the following position:

RA (J2000) = 05 01 06.47
Dec (J2000) = +45 16 28.0

with an uncertainty of 0.2".  This is 7" from the XRT position of GRB
080822 reported by Holland et al. (GCN 8112), thus formally outside the
reported 90% error circle with the radius of 2.6".

The above mentioned star is present in USNO-B1.0 catalogue as USNO-B1
1352-0128683 (RA = 05 01 06.42, Dec = +45 16 27.6) with the following
magnitudes:

B1=19.11, R1=15.99, B2=17.74, R2=15.97, I=16.52.

Animation of two Blue and two Red plates, as well as color-combined
(BRIR) images covering 101"x101" area around the variable star are
available at <http://hea.iki.rssi.ru/~denis/SGR0501+4516.html>.

It should be also noted that the variable object is located 16" from the
ROSAT source 1RXS J050107.9+451631 (catalog position error 13") with the
hardness ratios HR1=0.96+/-0.08, HR2=1.00+/-0.12.  These values are
typical for X-ray binaries, including X-ray transients.  Thus, the
variable star is most likely associated with the ROSAT source.  The
optical spectroscopy of this star is encouraged.  Also the follow-up
X-ray observations of SGR 0501+4846 are required to reveal its true
nature, improve the position accuracy and check the possible identification.

This message can be cited.


GRB_name: GRB080818B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8116
SUBJECT: GRB080818B: GLAST Burst Monitor detection
DATE:    08/08/22 20:45:13 GMT
FROM:    Colleen A. Wilson at NASA/MSFC/NSSTC  <colleen.wilson@nasa.gov>

C.A. Wilson-Hodge (NASA/MSFC), A.J. van der Horst (NASA/ORAU), report on
behalf of the GLAST Burst Monitor Team:

"At 22:40:49 UT on 18 August 2008, the GLAST Burst Monitor (GBM)
triggered and located GRB 080818B (trigger 240792050 / 080818.945).
The on-ground calculated location, using the GBM trigger data, is
RA = 98.1, Dec = +7.4 (J2000 degrees)(equivalent to J2000 06h 32m, +7d 60')
with an uncertainty of 7.7 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is
currently estimated to be 2 to 3 degrees).  The angle from the Large Area
Telescope (LAT) boresight is 68 degrees.

This GRB was about 10 s long with one peak.  The time-averaged spectrum
(8-950 keV) from T-1.3 to T+10.0 s is best fit with a Comptonized spectrum
(power law times exponential cutoff).   The power law index is -1.3 +/- 0.1
and the cutoff energy, parameterized as Epeak, is 80 +/- 11 keV. The
fluence from 50-300 keV is 1E-6 erg/cm^2.
 
The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog.


GRB_name: GRB080822B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8117
SUBJECT: GRB 080822B: Swift detection of a burst
DATE:    08/08/22 21:27:55 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. T. Holland (CRESST/USRA/GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (NASA/UMBC), V. Mangano (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), C. Pagani (PSU), D. M. Palmer (LANL),
M. Perri (ASDC), B. Preger (ASDC), R. L. C. Starling (U Leicester)
and G. Stratta (ASDC) report on behalf of the Swift Team:

At 21:02:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080822B (trigger=321376).  Swift did not slew to this burst
because of the Moon observing constraint.  It will come out of Moon constraint
early 26 Aug 08 UT. 
The BAT on-board calculated location is 
RA, Dec 63.495, +25.743, which is 
   RA(J2000)  =  04h 13m 59s
   Dec(J2000) = +25d 44' 34"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT TDRSS light curve does not show anything
significant which is typical for an image trigger. 

Burst Advocate for this burst is S. T. Holland (sholland AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

[GCN OPS NOTE(22aug08): Per author's request, the missing "B" suffix on the
burst name was added.]


GRB_name: GRB080822A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8122
SUBJECT: New Soft Gamma Repeater 0501+4516 (GRB 080822): GLAST Burst Monitor detection 
DATE:    08/08/23 10:01:50 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

Andreas von Kienlin (MPE), N.P. Bhat (UAH), E. Bissaldi (MPE), 
M.S. Briggs (UAH), V. Connaughton (UAH), R. Diehl (MPE), 
G.J. Fishman (NASA/MSFC), L. Gibby (NASA/MSFC), J. Greiner (MPE), 
A.S. Hoover (LANL), A.J. van der Horst (NASA/ORAU), R.M. Kippen (LANL), 
C. Kouveliotou (NASA/MSFC), G.G. Lichti (MPE), C.A. Meegan (NASA/MSFC), 
S. McBreen (MPE), W.S. Paciesas (UAH), R.D. Preece (UAH), H. Steinle (MPE), 
M.S. Wallace (LANL), and C.A. Wilson-Hodge (NASA/MSFC)report: 

"At 12:41:59  UT on 2008 Aug 22, the GLAST Burst Monitor (GBM) triggered 
 on the new Soft Gamma Repeater 0501+4516 (GRB 080822) 
(GBM 080822.529 / trigger 241101720), reported by SWIFT 
(Holland et al., GCN Circ. 8112, Barthelmy et al, GCN Circ. 8113 
and GCN Circ. 8119). 

The on-ground calculated location, using the GBM trigger data, is 
RA = 86.2, Dec = +43.5 (J2000 degrees),(equivalent to J2000 05h 45m, +43d
30'), 
with an uncertainty of 3.3 degrees (radius, 1-sigma containment, statistical

only). The true location error is 8.0 degrees for this soft, short event.

This event has a duration of about 80 ms. The spectrum in the 
10 keV to 100 keV energy band is well fit by a power law function
with an index of -1.6 +/-0.1. The high temperature for an 
optically thin thermal bremsstrahlung (OTTB) fit is: 71 +/-13 keV.  
These results are consistent with the trigger clearly being seen to 100 keV.

The spectral analysis results presented above are preliminary."


GRB_name: GRB080822B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8123
SUBJECT: GRB 080822B: MASTER optical observation 
DATE:    08/08/23 11:08:44 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

MASTER-Net Team:

D.Kuvshinov, V. Lipunov, V.Kornilov,  E.Gorbovskoy,
A.Belinski, N.Shatskiy, N.Tyurina,
Sternberg Astronomical Institute, Moscow Union 'Optic'

A. Tlatov, I.Golubov
Kislovodsk Solar Station of the Pulkovo observatory

V.Krushinski, I.Zalognikh
Ural State University, Kourovka

S.Yazev, K.Ivanov
Irkutsk State University


MASTER  robotic Net (Moscow region, http://observ.pereplet.ru)
responded to GRB080822B (Holland  et al., GCN Circ 8117) by hand
  due to internet problem at the Moscow Region Site.
The first image was started at 2008-08-22 21:21:35 UT, 18m 43s  after the 
GRB time.
The unfiltered image is calibrated relative to USNO A2.0 (0.8 R + 0.2 B).
The robot did not find OT-candidate in error box.


T-Tgrb    Mean Time     Exposition     Limit   Coadd?

1123 s     1138 s          30 s         17.0      no

1123s      1692 s         25x30 s       18.8     yes


The message can be cited.
mailto: lipunov@sai.msu.ru


GRB_name: GRB080822B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8128
SUBJECT: GRB 080822B, Swift-BAT refined analysis
DATE:    08/08/24 21:02:00 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

G. Sato (ISAS), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
S. T. Holland (CRESST/USRA/GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
K. McLean (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+903 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080822B (trigger #321376)
(Holland, et al., GCN Circ. 8117).  The BAT ground-calculated position is
RA, Dec = 63.560, 25.760 deg, which is 
   RA(J2000)  =  04h 14m 14.5s 
   Dec(J2000) = +25d 45' 35.5" 
with an uncertainty of 3.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 82%.
 
The mask-weighted light curve shows weak emission starting around T-50 sec
and ending around T+70 sec.  T90 (15-350 keV) is 64 +- 20 sec
(estimated error including systematics).
 
The time-averaged spectrum from T+0.0 to T+64.0 sec is fit by a power law.
This fit gives a photon index 2.54 +- 0.5.  (chi squared 76.5 for 59 d.o.f.).
For this model the total fluence in the 15-150 keV band is 1.7 +- 0.6 x 10^-07
erg/cm2 and the 1-sec peak flux measured from T+0.00 sec in the 15-150 keV band
is 0.06 +- 0.02 ph/cm2/sec.  All the quoted errors are at the 90%
confidence level. 

We note that this is a weak detection for BAT and that we can not rule out
a non-burst explanation for this trigger.


GRB_name: GRB080825B
Detection_method: superAGILE
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8133
SUBJECT: GRB 080825B: GRB Localization by SuperAGILE
DATE:    08/08/25 20:11:07 GMT
FROM:    Marco Feroci at IASF/INAF  <feroci@iasf-roma.inaf.it>

Y. Evangelista, P. Soffitta, E. Del Monte, I. Donnarumma, M. Feroci, 
F. Lazzarotto, L. Pacciani, E. Costa, I. Lapshov, M. Rapisarda
(INAF/IASF Rome), A. Giuliani, S. Vercellone, A. Chen,
S. Mereghetti, A. Pellizzoni, F. Perotti, F. Fornari, P. 
Caraveo (INAF/IASF Milan), A. Bulgarelli, F. Gianotti,
M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi,
M. Galli, (INAF/IASF Bologna), M. Tavani, G. Pucella, F. D'Ammando, V. 
Vittorini, A. Argan, A. Trois (INAF/IASF Rome), G. Barbiellini,
F. Longo (INFN Trieste), P. Picozza, A. Morselli (INFN Roma-2),
M. Prest, E. Vallazza (Universita' dell'Insubria), P. Lipari,
D. Zanello (INFN Roma-1), and  P. Giommi, C. Pittori, B. Preger,
P. Santolamazza, F. Verrecchia (ASDC) and L. Salotti (ASI), 
on behalf of the AGILE Team, report:

"SuperAGILE detected a gamma ray burst on 25 August 2008, at 17:46:40 UT. 
The event was approximately 10 degrees off-axis, with a duration of about 
50 s in the 20-60 keV energy range, with a multi-peaked structure.
The burst position was reconstructed  as (RA, Dec) 
(209.281 deg, -68.943 deg), which is:

RA(J2000)  = 13h 57m 07.42s
Dec(J2000) = -68d 56' 34.0"

with an uncertainty of 3' radius. The given uncertainty accounts
for both the statistical and systematic errors.

An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress."

This message may be cited.


GRB_name: GRB080825B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8135
SUBJECT: GRB 080825B - optical counterpart candidate
DATE:    08/08/26 01:15:20 GMT
FROM:    Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr  <cthoene@astro.ku.dk>

Christina C. Thoene (DARK/NBI), Antonio de Ugarte Postigo (ESO) and Davide
Ricci (Univ. of Liege) report:

We observed the complete 3' error box of the SuperAGILE GRB 080825B
(Evangelista et al., GCN 8133) using the Danish 1.54m + DFOSC at La
Silla (Chile) starting Aug. 25 at 23:18:31 UT (5.53 hours after the
burst). In the first I-band frame we detect a new source not present
in the DSS-2 catalogue at the following coordinates (J2000 +/-
0.7"):

RA: 13:56:48.22
DEC: -68:57:18.5

for which we measure an I-band magnitude of 17.4 +/- 0.2 as compared
to several USNO-B1 stars.

A finding chart can be found at:
http://www.sc.eso.org/~adeugart/GRB/080825/080825.jpg

Further observations and analysis are ongoing to establish the connection
to the GRB and the fading of the object.


GRB_name: GRB080825A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8137
SUBJECT: GRB080825: Afterglow confirmation and redshift estimate
DATE:    08/08/26 02:43:47 GMT
FROM:    Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr  <cthoene@astro.ku.dk>

Antonio de Ugarte Postigo (ESO), Christina C. Thoene (DARK/NBI) and Davide
Ricci (Univ. of Liege) report:

We obtained further observations of the candidate optical counterpart
of GRB 080825B (Evangelista et al., GCN 8133) in Bessel-UBVRI bands. The
object is found to be fading in a series of I band images. From 23:18 UT
to 01:41 UT, the candidate afterglow faded from 17.4+/-0.2 to 18.1+/-0.2
mag compared to several USNO-B stars, confirming the reality of the
afterglow proposed by Thoene et al. (GCN 8135). Furthermore the object is
detected in V, R and I band, but not in U and B. We therefore derive a
redshift limit of z>3 if the nondetection is due to Lyman alpha absorption
or z>4.3 if due to the Lyman limit.

Further analysis is ongoing.


GRB_name: GRB080825B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8140
SUBJECT: GRB 080825B: Swift-XRT team analysis
DATE:    08/08/27 02:06:25 GMT
FROM:    Claudio Pagani at PSU/Swift-XRT  <pagani@astro.psu.edu>

C. Pagani reports on behalf of the Swift-XRT team:

We have analyzed the Swift XRT data on the field of the AGILE detected GRB
080825B (Evangelista et al., GCN Circ. 8133), consisting of 7.5 ks of Photon
Counting data collected from T0+44 ks to T0+78 ks.

We detect a point source at the position of the optical afterglow (Thoene et
al., GCN Circ. 8135). During the XRT observations the source faded from an
initial count rate of 0.05 counts/s to a later count rate of 0.01 counts/s.

The spectrum from the PC data can be fitted by an absorbed power law model with
photon index of 2.1 and the absorption consistent with the Galactic value along
the line of sight (2.10e21 cm^-2, Kalberla et al. 2005).  The average observed
(unabsorbed) flux of the PC mode data is 5.8e-13 (9.0e-13) ergs cm^-2 s^-1.

This Circular is an official product of the Swift-XRT team.


GRB_name: GRB080825C
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8141
SUBJECT: GRB080825C: GLAST Burst Monitor detection
DATE:    08/08/27 03:38:23 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

A.J. van der Horst (NASA/ORAU) and V. Connaughton (UAH) report on behalf
of the Fermi GBM Team:

"At 14:13:48 UT on 25 August 2008, the Fermi GBM triggered and located
GRB 080825C (trigger 241366429 / 080825.593).
The on-ground calculated location, using the GBM trigger data, is
RA = 232.2, Dec = -4.9 (J2000 degrees, equivalent to 15h 29m, -4d 54'),
with an uncertainty of 1.5 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is
currently estimated to be 2 to 3 degrees). The angle from the Fermi
LAT boresight is 60 degrees.

This GRB has several peaks, with T90 (50-300 keV) = 22 s and
T50 (50-300 keV) = 12 s. The time-averaged spectrum (8-910 keV)
from T0 to T0+22.1 s is best fit by a Band function with
Epeak = 155 +/- 5 keV, alpha = -0.39 +/- 0.04, and beta = -2.34 +/- 0.09.
The fluence (50-300 keV) is 2.4E-5 erg/cm^2.

The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog."


GRB_name: GRB080825B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8142
SUBJECT: Konus-Wind observation of GRB 080825B
DATE:    08/08/27 13:26:45 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin,
D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov
and T. Cline, on behalf of the Konus-Wind team report:

The most intense part of the GRB 080825B localized by SuperAGILE 
(Evangelista et al., GCN 8133) triggered Konus-Wind
at T0=64012.487 s UT (17:46:52.487).

The burst light curve shows a weak emission starting at ~T0-70s,
the main multipeaked part (from ~T0-5s to ~T0+15s), and an extended 
emission seen up to ~T0+40s.

As observed by Konus-Wind the burst
had a fluence of 7.81(-0.70, +0.83)x10^-6 erg/cm2,
and a 256-ms peak flux measured from T0-0.080 s
of 1.21(-0.31, +0.32)x10^-6 erg/cm2/s
(both in the 20 keV - 1 MeV energy range).

The spectrum of the most intense part
(from T0 to T0+16.640 s) is well fitted (in the 20 keV-1 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.13(-0.36, +0.40),
and Ep = 72(-9, +11) keV (chi2 = 40.0/51 dof).
Fitting by GRBM (Band) model yields:
the low-energy photon index is alpha = -1.05(-0.38, +0.56),
the high energy photon index beta < -2.52,
the peak energy Ep = 71(-9, +11) keV (chi2 = 38.8/50 dof).
All the quoted errors are at the 90% confidence level.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB080825_T64012/


GRB_name: GRB080825B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8143
SUBJECT: GRB 080825B: pseudo-z= 0.83 from prompt emission spectrum
DATE:    08/08/27 14:29:29 GMT
FROM:    Alexandre Pelangeon at LATT,OMP,Toulouse  <alexandre.pelangeon@ast.obs-mip.fr>

We used the spectral parameters of GRB 080825B
provided by Golenetskii et al. (GCNC 8142) to compute
the spectral pseudo-redshift(**) of this burst localized
by SuperAGILE (Evangelista et al., GCN 8133).

We find a pseudo-redshift pz= 0.83  0.30


(**) cf. http://www.ast.obs-mip.fr/grb/pz


GRB_name: GRB080824A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8144
SUBJECT: GRB 080824: Fermi Gamma Ray Burst Monitor detection
DATE:    08/08/27 16:15:00 GMT
FROM:    Colleen A. Wilson at NASA/MSFC/NSSTC  <colleen.wilson@nasa.gov>

C.A. Wilson-Hodge (NASA/MSFC) reports on behalf of the Fermi GBM Team:

"At 21:48:54 UT on 24 August 2008, the Fermi GBM triggered and located
GRB 080824 (trigger 241307335 / 080824909). The on-ground calculated
location, using the Fermi GBM trigger data, is RA = 120.3, Dec = -3.2
(J2000 degrees)(equivalent to J2000 08h 01m, -3d 10'), with a statistical
uncertainty of less than 1 degree (radius, 1-sigma containment; there is
additionally a systematic error which is currently estimated to be 2 to 3
degrees). The angle from the Fermi LAT boresight is 17 degrees.

This GRB was single peaked with a tail. Estimated values (50-300 keV) for
T50 and T90 are 6.1 and 28 s, respectively. The time-averaged spectrum from
T-5.9s to T+6.4 s is best fit with a Band function spectrum with
alpha = -0.4 +/- 0.2, Epeak = 100 +/- 16 keV, and beta = -2.1 +/- 0.2. The
fluence (50-300 keV) is 2.3E-6 erg/cm^2."

The spectral analysis results presented above are preliminary; the final
results will be published in the Fermi GBM GRB Catalog.


GRB_name: GRB080823A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8145
SUBJECT: GRB080823: Fermi Gamma-ray Burst Monitor detection
DATE:    08/08/27 16:16:58 GMT
FROM:    Sheila McBreen at MPE  <smcbreen@mpe.mpg.de>

S. McBreen , A. von Kienlin and E. Bissaldi (MPE) report on
behalf of the Fermi GBM Team:

"At 08:42:13 UT on 23 August 2008, the Fermi GBM triggered and located  
GRB 080823 (trigger 241173734 / 080823.363).
The on-ground calculated  location, using the GBM trigger data, is
 RA = 91.8 , Dec = -40.6   (J2000 degrees, equivalent to 06h 07m, -40d
36'), with an uncertainty  of 3.3 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is
currently estimated  to be 2 to 3 degrees). The angle from the Fermi LAT
boresight is 77 degrees.

This event comprises a small pulse at T0-3 sec, a main pulse with
substructure from 0 to 20 sec and a weaker pulse from 20 to 40 sec.   T90
(50-300 keV) is about 46 sec. The time-averaged  spectrum from T0 to
T0+18s is best fit by a power law function with an exponential high energy
cutoff. The cutoff energy,  parameterized as Epeak, is  164.7+/-34.2 keV
and the power law index is -1.2 +/-0.2. The fluence (50-300 keV) over T90
is 4.1e-6 erg/cm^2.

The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog."


GRB_name: GRB080828A
Detection_method: superAGILE
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8151
SUBJECT: GRB 080828: SuperAGILE GRB Localization
DATE:    08/08/28 07:10:09 GMT
FROM:    Marco Feroci at IASF/INAF  <feroci@iasf-roma.inaf.it>

E. Del Monte, P. Soffitta, I. Donnarumma, Y. Evangelista, M. Feroci, 
F. Lazzarotto, L. Pacciani, E. Costa, I. Lapshov, M. Rapisarda
(INAF/IASF Rome), A. Giuliani, S. Vercellone, A. Chen,
S. Mereghetti, A. Pellizzoni, F. Perotti, F. Fornari, P. 
Caraveo (INAF/IASF Milan), A. Bulgarelli, F. Gianotti,
M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi,
M. Galli, (INAF/IASF Bologna), M. Tavani, G. Pucella, F. D'Ammando, V. 
Vittorini, A. Argan, A. Trois (INAF/IASF Rome), G. Barbiellini,
F. Longo (INFN Trieste), P. Picozza, A. Morselli (INFN Roma-2),
M. Prest, E. Vallazza (Universita' dell'Insubria), P. Lipari,
D. Zanello (INFN Roma-1), and  P. Giommi, C. Pittori, B. Preger,
P. Santolamazza, F. Verrecchia (ASDC) and L. Salotti (ASI), 
on behalf of the AGILE Team, report:

"SuperAGILE detected a gamma ray burst on 28 August 2008, at 03:14:45 UT. 
The event had a duration of about 25 s in the 20-60 keV energy range, 
with a single-peak structure.
The burst position was reconstructed 
as (RA, Dec) (199.626 deg, -65.930 deg), which is:

RA(J2000)  = 13h 18m 30.32s
Dec(J2000) = -65d 55' 48.2"

with an uncertainty of 3' radius. The given uncertainty accounts
for both the statistical and systematic errors.

An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress."

This message may be cited.


GRB_name: GRB080828A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8157
SUBJECT: GRB 080828: Swift-XRT detection of a possible X-ray afterglow
DATE:    08/08/28 21:53:32 GMT
FROM:    Andy Beardmore at U Leicester  <apb@star.le.ac.uk>

A.P. Beardmore and R.L.C. Starling (U. Leicester) report on behalf of the
Swift-XRT team:

The Swift-XRT began observations of the field of the SuperAGILE detected
GRB 080828 (Del Monte et al., GCN Circ 8151) at 2008-08-28 14:07:17UT,
39.15 ks after  the burst. In 4.96 ks of photon counting mode data we
detect a faint, uncatalogued X-ray source at RA, Dec 199.5871, -65.9405
which is
RA  (J2000) =  13:18:20.91
Dec (J2000) = -65:56:25.8
with an uncertainty of 4.2 arcsec (radius, 90% containment).
This source  is 1.1 arcmin away from the AGILE position and within
its error circle.

The measured XRT count rate is 0.008 +/- 0.001 count/s. At this stage
we cannot tell whether the source is fading.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB080825B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8158
SUBJECT: GRB080825B: Swift/UVOT Upper Limits
DATE:    08/08/29 01:10:54 GMT
FROM:    Peter Brown at PSU  <pbrown@astro.psu.edu>

P. J. Brown (PSU) reports on behalf of the Swift/UVOT team:

The Swift/UVOT observed the field of GRB 080825B
starting about 45 ks after the SuperAGILE detection
(Evangelista et al., GCN Circ. 8133).  We do not detect
the optical afterglow seen by Thoene et al. (GCN Circ. 8135)
in any of the UVOT filters down to the following 3 sigma
upper limits.

Filter  T_start(s) T_stop  Exp(s)   MagLimit
white   49916      50823   885      >22.1
uvw2    44237      78448   1903     >21.5
uvm2    61477      67242   988      >20.8
uvw1    67248      73020   1036     >20.9
u       73027      73522   483      >20.8
b       49004      49911   885      >21.2
v       45144      61472   1234     >20.5

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E(B-V) ~ 0.25 mag (Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383,627).


GRB_name: GRB080828A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8161
SUBJECT: GRB080828: Swift/UVOT Upper Limits
DATE:    08/08/29 17:08:41 GMT
FROM:    Paul Ward at MSSL  <paw@mssl.ucl.ac.uk>

P. Ward (MSSL-UCL) and W. Baumgartner (GSFC/UMBC) report on behalf of the 
Swift/UVOT team:

The Swift/UVOT observed the field of GRB 080828 starting 39.15ks after the 
SuperAGILE detection (Del Monte et al., GCN Circ. 8151).  We do not detect 
any afterglow at the Swift XRT position reported by Beardmore et al.
(GCN Circ. 8157) in any of the following UVOT filters down to the given 3
sigma upper limits.

Filter T_start(s) T_stop Exp(s)  MagLimit

White  46201      46561  355.8   > 21.40
u      44376      51948  1798.8  > 20.65
b      45289      52309  1250.3  > 21.33
w1     40064      51035  1615.6  > 21.05
m2     39156      40055  899.8   > 20.50

The photometry is on the UVOT photometric system described in Poole et al. 
(2008, MNRAS, 383,627). The above magnitudes are not corrected for the 
Galactic extinction corresponding to a reddening of E(B-V) ~ 0.81 mag 
(Schlegel et al., 1998).


GRB_name: GRB080830A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8167
SUBJECT: GRB 080830: Fermi Gamma-ray Burst Monitor detection
DATE:    08/09/02 16:21:34 GMT
FROM:    Sheila McBreen at MPE  <smcbreen@mpe.mpg.de>

S. McBreen, E. Bissaldi and A. von Kienlin (MPE)  report on behalf
of the Fermi Gamma-ray Burst Monitor Team:

"At 08:50:16 UT on 30 August 2008, the Fermi Gamma-ray Burst
Monitor (GBM) triggered and located GRB 080830 (trigger 241779017
/080830.368). The on-ground calculated location, using the GBM
trigger data, is RA = 158.2, Dec = +33.6 (J2000 degrees)
(equivalent to J2000 10h 33m, +33d 36'), with an uncertainty
of 4.0 degrees (radius, 1-sigma containment, statistical only;
there is additionally a systematic error which is currently
estimated to be 2 to 3 degrees). The angle from the Fermi LAT
boresight is 23 degrees.

This event comprises four pulses beginning at T0-3 sec. The
main emission occurs during the first 20 sec and T90 (50-300 keV)
about is 45 sec. The time-averaged spectrum from T-3 to T+28 sec
is adequately fit by a power law function with an exponential
high energy cutoff.  The power law index is -0.88 +/-0.12 and
the cutoff energy, parameterized as Epeak, is 280 +/-63 keV.

A slightly better fit is obtained with the Band function with the 
following parameters: alpha = -0.59 +/- 0.28, Epeak = 154 +/-57 keV
and beta = -1.69 +/- 0.16.

The fluence (50-300 keV) over T90 is 4.6E-06 ergs/cm2.

The spectral analysis results presented above are preliminary;
the final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB080903A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8169
SUBJECT: GRB 080903: Swift detection of a burst
DATE:    08/09/03 01:38:31 GMT
FROM:    David Burrows at PSU/Swift  <dxb15@psu.edu>

D. Grupe (PSU), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
M. M. Chester (PSU), J. R. Cummings (NASA/UMBC),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU)
report on behalf of the Swift Team:

At 01:12:23 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080903 (trigger=323542).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 86.797, +51.326 which is 
   RA(J2000) = 05h 47m 11s
   Dec(J2000) = +51d 19' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty).  The BAT light curve showed a broad single-peaked
structure with a duration of about 50 sec.  The peak count rate
was 1250 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 01:13:21.8 UT, 58.5 seconds after
the BAT trigger. Using promptly downlinked data we find a bright, fading,
uncatalogued X-ray source located at RA, Dec 86.79071, 51.26363 which
is equivalent to:
   RA(J2000)  = 05h 47m 9.77s
   Dec(J2000) = +51d 15' 49.1"
with an uncertainty of 3.0 arcseconds (radius, 90% containment). This
location is 224 arcseconds from the BAT onboard position, outside the
on-board BAT error circle, but within the BAT ground-calculated error
circle. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.67e+21 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 1.80e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 400 seconds with the V filter
starting 75  seconds after the BAT trigger. No afterglow candidate
has been found in the  initial data products. The 2.7'x2.7' sub-image
covers 100% of the XRT error  circle. The 3-sigma upper limit at the
location of the XRT candidate is 19.4 mag. No correction has  been
made for the expected extinction of about 0.7 magnitudes. 

Burst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080903A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8170
SUBJECT: GRB 080903: ROTSE-III Optical Limits
DATE:    08/09/03 02:12:02 GMT
FROM:    Fang Yuan at ROTSE  <yuanfang@umich.edu>

F. Yuan (U Mich), W. Rujopakarn (Steward), H. Swan (U Mich), D.A.  
Smith (Guilford), T. Guver (U Arizona) report on behalf of the ROTSE  
collaboration:

ROTSE-IIId, located at the Turkish National Observatory at  
Bakirlitepe, Turkey, responded to GRB 080903 (Swift trigger 323542;  
Grupe et al., GCN 8169), producing images beginning 6.7 s after the  
GCN notice time. An automated response took the first image at  
01:12:47.7 UT, 24.4 s after the burst, and during the gamma-ray  
emission, under fair conditions. We took 10 5-sec, 10 20-sec and 30 60- 
sec exposures. These unfiltered images are calibrated relative to USNO  
A2.0 (R). Imaging is on going.

Comparison to the DSS (second epoch) reveals no new sources within the  
3-sigma Swift/BAT error circle or the XRT error circle, for both  
single images and coadding into sets of 10. Individual images have  
limiting magnitudes ranging from 16.5-17.7; we set the following  
specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
01:12:47.7   01:14:55.9       128     17.7           24.4       Y
01:15:04.6   01:19:42.4       277     18.3          161.3       Y


GRB_name: GRB080903A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8171
SUBJECT: GRB 080903: TAROT Calern observatory optical observations
DATE:    08/09/03 03:45:24 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz@free.fr>

Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 080903 detected by SWIFT
(trigger 323542) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

The observations started 29.1s after the GRB trigger
(11.4s after the notice). The elevation of the field increased
from 38 degrees above horizon and weather conditions
were excellents.

The date of trigger : t0 = 2008-09-03T01:12:23.3

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT at the XRT position provided
by Grupe et al. (GCNC 8169):
t0+29.1s to t0+89.1s : R > 17.1

The second image is 30.0s exposure in tracking mode:
t0+95.9s to t0+125.9s : R > 18.2

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon=160.7489 lat=+11.6608
and the galactic extinction in R band is 0.6 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.


GRB_name: GRB080903A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8172
SUBJECT: GRB 080903: Optical afterglow candidate
DATE:    08/09/03 03:58:28 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (ESO, Chile), A.J. Castro-Tirado,
V. Casanova, J. Gorosabel, M. Jelinek, M. Guerrero
(IAA-CSIC, Granada) report on behalf of a larger collaboration:

We have observed the field of GRB 080903 (Grupe et al., GCN 8169)
using the 1.5m OSN telescope at Sierra Nevada Observatory (Granada)
in V, R and I bands begining at 02:30 UT (78 min after the burst).
We detect a source of I~21.0 on the edge of the XRT error box at
the following coordinates (J2000 +/- 0.5"):

R.A.: 05:47:10.08
Dec.: +51:15:50.9

Further observations are ongoing from OSN and NOT to check the
colour and variability of this source.


GRB_name: GRB080903A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8173
SUBJECT: GRB 080903: Astrotel-Caucasus optical observations
DATE:    08/09/03 05:40:54 GMT
FROM:    Denis Denissenko at IKI, Moscow  <denis@hea.iki.rssi.ru>

S. Korotkiy (Ka-Dar Observatory), T. Kryachko, B. Satovskiy (Astrotel 
Observatory, KSU/AST) and D. Denisenko (IKI) report:

We have observed the error box of Swift gamma-ray burst GRB 080903 
(Grupe et al., GCN 8169) with 0.3-m f/7.8 Astrotel-Caucasus telescope (+ 
Apogee Alta U9000 CCD camera) at Kazan State University Mountain Station 
(Karachay-Cherkessia, Russia).  The first 120-sec unfiltered exposure 
was taken at 01:18:21 UT, 358 seconds after the burst trigger.  Inside 
the XRT error circle we have found a new source not present on DSS 
plates at the following coordinates (J2000):

05 47 10.05 +51 15 50.9

(astrometry relative to USNO-A2.0 catalogue, accuracy +/-0.2").

Using the nearby USNO-A2.0 1350-06155883 (05 47 16.36 +51 15 56.4) with 
R=18.1 as a comparison star, we have measured CR (unfiltered with Red 
zero point) magnitude 19.1 for the afterglow candidate.  The limiting 
magnitude of the image is 20.5.

Four additional images were obtained with the approaching twilight and 
brightening sky background.  The object is still present on the second 
120-sec exposure obtained at 01:22:09 UT, but not detected on the next 
images.

The crop of Astrotel-Caucasus image is available at:

http://www.astroalert.su/files/grb080903_crop_x4_size.jpg

Color-combined (BRIR) DSS image of the same area for comparison:

http://hea.iki.rssi.ru/~denis/GRB080903-BRIR-crop.jpg


GRB_name: GRB080903A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8174
SUBJECT: GRB 080903: Liverpool Telescope observations
DATE:    08/09/03 09:10:06 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi (INAF-OAB), R. J. Smith (LJMU), A. Gomboc (U. Ljubljana)
on behalf of a larger collaboration report:

On 2008 September 03 (03:32:18 UT) we began observing the field of
GRB 080903 (Grupe et al. GCN Circ. 8169) with the Liverpool Telescope
using the SDSS i filter.

We clearly detect the optical afterglow candidate reported by de
Ugarte Postigo et al. (GCN Circ. 8172) and Korotkiy et al.
(GCN Circ. 8173). We found the following magnitudes:

Telescope   Filter  T_mid[hr]   Exposure[s]      Mag
-------------------------------------------------------------
LT          i'         2.59       6x300        21.32 +/- 0.07
LT          i'         4.08       6x300        21.52 +/- 0.11
-------------------------------------------------------------

The calibration was performed using the I magnitude of the following
nearby USNOB1 catalogue star: 05:47:14.30, +51:15:32.8, using I=14.77.


GRB_name: GRB080903A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8175
SUBJECT: GRB 080903: optical observations
DATE:    08/09/03 12:39:23 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

Andreev M., Sergeev A., Karpov N. (Terskol Branch of Institute of
Astronomy),  Khramtsova M. (The Ural State University),  Petkov V.(BNO INR
RAS), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration
report:

We observed the field of GRB 080903 (Grupe et al. GCN 8169)  with Z-600 and
Celestron 11" telescopes of Mt. Terskol observatory.  A set of  60 s
exposures in R filter was taken with Z-600 starting 22 minutes after burst
onset. In a combined image we clearly detect afterglow candidate (Ugarte
Postigo et al. GCN 8172, Korotkiy et al. GCN 8173). Preliminary photometry
is based on USNO-A2.0 1350-06155883 star (05 47 16.36 +51 15 56.4) assuming
R=18.1:

T0+       Exp.        R_mag
(Mid)

1673 sec. 10x60 sec.  19.35 +/-0.2

The afterglow is also detected in unfiltered combined image (40x10s) taken
with Celestron 11" telescope at Tmid = 1280 s. The photometry is underway.


GRB_name: GRB080903A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8176
SUBJECT: GRB 080903, Swift-BAT refined analysis
DATE:    08/09/03 14:25:14 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. Tueller (GSFC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Grupe (PSU), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
K. McLean (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+723 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080903 (trigger #323542)
(Grupe, et al., GCN Circ. 8169).  The BAT ground-calculated position is
RA, Dec = 86.790, 51.256 deg, which is 
   RA(J2000)  =  05h 47m 09.6s 
   Dec(J2000) = +51d 15' 22.4" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows a single FRED peak starting at ~T-5 sec
and ending at ~T+80 sec.  There appears to be very low level emission out
to ~T+500 sec.  T90 (15-350 keV) is 66 +- 11 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-10.5 to T+68.0 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.84 +- 0.52, 
and Epeak of 60 +- 15 keV (chi squared 63 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.4 +- 0.1 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T-2.46 sec in the 15-150 keV band is
0.8 +- 0.1 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.72 +- 0.10 (chi squared 73 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/323542/BA/


GRB_name: GRB080903A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8177
SUBJECT: GRB 080903: Enhanced Swift-XRT position
DATE:    08/09/03 15:05:26 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3613 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 080903, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 86.79206, +51.26433 which is equivalent
to:

RA (J2000): 05h 47m 10.10s
Dec (J2000): +51d 15' 51.6"

with an uncertainty of 1.6 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB080903A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8178
SUBJECT: GRB 080903: Swift-XRT Refined Analysis
DATE:    08/09/03 18:02:51 GMT
FROM:    Dirk Grupe at PSU/Swift-XRT  <grupe@astro.psu.edu>

Dirk Grupe (PSU) and Phil Evans (U Leicester) report on behalf of the 
Swift-XRT team:


The XRT began observing the field of GRB 080903 (trigger=323542; Grupe 
et al.,
GCN Circ 8169) at 01:13:21.8 UT, 58.5 seconds after
the BAT trigger.

The enhanced XRT position given in GCN Circ 8177 (Goad et al)
is 30.3" away from the ground-processed BAT position given in GCN Circ. 
8176
(Tueller et al.),  consistent with that position.

The 0.3-10 keV X-ray light curve starts at a level of 2e-9 ergs/s/cm2 (40
counts/s) in the XRT with a rather flat decay slope at these early times of
alpha = 1.00+/-0.04. The light curve breaks at about 1 ks after the 
burst and
steepens dramatically to alpha = 2.47+/-0.14. If this decay slope 
continues as is,
we predict an XRT count rate at T0+24 hours of 3e-5 counts/s or 2e-15
ergs/s/cm2, so undetectable for XRT.


The spectrum of the Windowed Timing data of the first orbit
can be fitted by an absorbed single powerlaw with an unusual flat photon
index Gamma = 0.94 +/- 0.06 and column density fixed to the Galactic 
value of
1.67e21 cm-2 in the direction of the burst. This photon index is 
consitent with
that found by the BAT in the 15-150 keV band (Gamma=0.84+/-0.52; Tueller 
et al.,
GCN Circ. 8176). The spectrum becomes slightly steeper at later times.
The Photon Counting mode data show an photon spectral slope of 
Gamma=1.23+/-0.16
with the absorption column density fixed to the Galactic value.


This Circular is an official product of the Swift-XRT team.


GRB_name: GRB080903A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8179
SUBJECT: GRB 080903: Swift/UVOT Observations
DATE:    08/09/03 19:06:16 GMT
FROM:    Frank Marshall at GSFC  <marshall@milkyway.gsfc.nasa.gov>

F.E. Marshall (NASA/GSFC) and D. Grupe (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT observed the field of GRB 080903 starting 75 s after
the BAT trigger (Grupe et al., GCN Circ. 8169). A source is
detected in the initial exposure in the V filter at the position
of the optical afterglow (de Ugarte Postigo et al., GCN Circ. 8172).
There is also a marginal (1.8 sigma) detection in the initial exposures
with the U filter. A valid detection in the U filter would
indicate a redshift of less than 3.3.

The magnitudes and 3-sigma upper limits in the UVOT photometric system 
(Poole et al. 2008, MNRAS, 383, 627) for detecting
a source in the first finding chart (FC) exposure and 
subsequent co-added exposures are:

Filter          T_start(s)   T_stop(s)      Exp(s)       Mag 

v (FC)              75          475          393         19.8 +/- 0.24
v                  595        28705         2596        >21.5
b                  555        12429         1307        >21.8
u                  530          829           58         20.0 +/- 0.47
u                 4906        34528         3049        >21.8
uvw1               506         7268          551        >21.0
uvm2               481         7160          655        >20.7
uvw2               571         6750          452        >21.2

The values quoted above are not corrected for the Galactic extinction due
to the reddening of E(B-V) = 0.22 in the direction of the burst 
(Schlegel et al. 1998).


GRB_name: GRB080905A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8180
SUBJECT: GRB 080905: Swift detection of a probably-short burst
DATE:    08/09/05 12:19:45 GMT
FROM:    Claudio Pagani at PSU/Swift-XRT  <pagani@astro.psu.edu>

C. Pagani (PSU), W. H. Baumgartner (GSFC/UMBC),
A. P. Beardmore (U Leicester), M. M. Chester (PSU),
J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), D. Grupe (PSU),
S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA),
J. Mao (INAF-OAB), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), B. Preger (ASDC), J. L. Racusin (PSU),
P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-IASFPA),
P. Schady (MSSL-UCL), M. Stamatikos (NASA/ORAU),
R. L. C. Starling (U Leicester), M. C. Stroh (PSU),
E. Troja (INAF-IASFPA), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU)
report on behalf of the Swift Team:

At 11:58:54 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080905 (trigger=323870).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 287.662, -18.877 which is 
   RA(J2000) = 19h 10m 39s
   Dec(J2000) = -18d 52' 37"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows 3 peaks with a total 
duration of about 2 sec.  The spectrum is hard, with most response above
25 keV in the BAT energy range. The peak count rate was ~4500 counts/sec 
(15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 12:01:05.3 UT, 130.4 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 287.67363,
-18.87986 which is equivalent to:
   RA(J2000)  = 19h 10m 41.67s
   Dec(J2000) = -18d 52' 47.5"
with an uncertainty of 2.8 arcseconds (radius, 90% containment). This
location is 40 arcseconds from the BAT onboard position, within the BAT
error circle. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
8.95e+20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm)  filter starting 114 seconds after the BAT trigger. No
afterglow candidate has  been found in the initial data products. The
2.7'x2.7' sub-image covers 100% of  the XRT error circle. The 3-sigma
upper limit at the location of the XRT position is 17.8 mag.  No
correction has been made for the expected extinction corresponding to
E(B-V) of 0.14. 

Burst Advocate for this burst is C. Pagani (pagani AT astro.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080905A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8181
SUBJECT: GRB 080905: R & I-band optical observations
DATE:    08/09/05 16:47:34 GMT
FROM:    Javier Gorosabel at IAA-CSIC  <jgu@iaa.es>

P. Tristram (MOA, Univ. of Canterbury),  A.J. Castro-Tirado
(IAA-CSIC, Granada), P. Yock  (Univ.  of  Auckland), J. Gorosabel
(IAA-CSIC, Granada), A. de Ugarte Postigo (ESO, Santiago), report on
behalf of a larger collaboration:

"Following the detection by Swift of GRB 080905 (Pagani et al. GCNC
8180), we have obtained R & I-band images at the 0.6m telescope of the
Mt. John Observatory, New Zealand. The images were taken starting on
Sep 5.529 UT (i.e. 43 min post-burst).

We do not detect any object brighter than R=20.8 and I=20.3 consistent
with the XRT position. We note the presence of  two extended R~15
(R~15.4) objects 8.5" (10") South (North-East)  (Object A  at
RA(J2000)=19:10:41.51, DEC(J2000)=-18:52:56.2  and Object B at
RA(J2000)=19:10:41.10, DEC(J2000)=-18:52:40.6, respectively) from the
XRT position which  could be hosting the probably-short GRB 080905. A
finding chart can be found at
http://www.sc.eso.org/~adeugart/GRB/080905/080905fc.jpg"


GRB_name: GRB080905B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8182
SUBJECT: GRB 080905B: Swift detection of a burst with possible optical counterpart
DATE:    08/09/05 17:22:03 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

M. C. Stroh (PSU), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), S. Immler (CRESST/GSFC/UMD),
J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
C. Pagani (PSU), K. L. Page (U Leicester), B. Preger (ASDC),
J. L. Racusin (PSU), T. Sakamoto (NASA/UMBC), P. Schady (MSSL-UCL),
R. L. C. Starling (U Leicester) and L. Vetere (PSU) report on behalf
of the Swift Team:

At 16:55:45 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080905B (trigger=323898).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 301.723, -62.571 which is 
   RA(J2000) = 20h 06m 53s
   Dec(J2000) = -62d 34' 15"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed three well separated
peaks each about 10 seconds long with a total burst duration of about 
90 sec.  The peak count rate was ~2000 counts/sec (15-350 keV), at ~4 sec 
after the trigger. 

The XRT began observing the field at 16:57:28.6 UT, 103.2 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 301.74027,
-62.56347 which is equivalent to:
   RA(J2000)  = 20h 06m 57.66s
   Dec(J2000) = -62d 33' 48.5"
with an uncertainty of 2.7 arcseconds (radius, 90% containment). This
location is 39 arcseconds from the BAT onboard position, within the BAT
error circle. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (3.49e+20
cm^-2, Kalberla et al. 2005), with an excess column of 1.7
(+1.47/-1.31) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 2.11e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 100 seconds with the White   
(160-650 nm)  filter starting 112 seconds after the BAT trigger.   
The 2.7'x2.7' sub-image covers 100% of the XRT error circle.  Inside 
the XRT error circle is a 16th mag source that is starlike in the DSS,
  but appears  extended or double in the UVOT image and may be an  
optical afterglow.  A second finding chart in V does not allow us to 
 confirm or reject the candidate at this time.  No  correction has  
been made for the  expected extinction corresponding to E(B-V) of   
0.05. 

Burst Advocate for this burst is M. C. Stroh (stroh AT astroh.org). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080825C
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8183
SUBJECT: GRB080825C: Fermi-LAT observations
DATE:    08/09/05 17:45:46 GMT
FROM:    Aurelien Bouvier at Stanford  <bouvier@stanford.edu>

A. Bouvier (SLAC), D. Band (GSFC), J. Bregeon (INFN Pisa), J. Chiang  
(SLAC), S. Cutini (ASDC), B. Dingus (LANL), N. Gehrels (GSFC), Y.  
Fukazawa (Hiroshima U), M. Hayashida (SLAC), F. Longo (INFN Trieste),  
J. McEnery (GSFC), M. Ohno (JAXA), N. Omodei (INFN Pisa), V. Pelassa  
(LPTA), F. Piron (LPTA), D. Sanchez (LLR), J. Scargle (NASA Ames), H.  
Tajima (SLAC), T. Tanaka (SLAC), G. Thayer (SLAC) on behalf of the  
Fermi LAT team:

We report a detection by the Fermi Large Area Telescope (LAT) of  
emission from GRB080825C, which was triggered by the Fermi Gamma-ray  
Burst Monitor (GBM) at 14:13:48 UT on August 25th 2008 (GCN 8141 by  
Van der Horst et al.). The angle of the GBM best localization (ra,  
dec=232.2,-4.6) with the LAT boresight was 60 deg at the time of the  
trigger which is on the edge of our field of view.

The data from the Fermi LAT shows a significant increase in the event  
rate within 10 degree of the GBM localization and up to 35 seconds  
after the GBM trigger that is spatially and temporally correlated  
with the GBM emission with a significance of more than 5 sigma. All  
the LAT events detected during the GBM emission have energies below 1  
GeV.

The best LAT on-ground localization is found to be  
RA,DEC=233.96,-4.72 deg with a 90% containment radius of 1.5 deg  
(statistical+systematics; 68% containment radius: 0.95 deg) which is  
consistent with the GBM localization.

This circular is an official product of the Fermi LAT team.


GRB_name: GRB080825C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8184
SUBJECT: GRB 080825C: Fermi GBM Spectral Analysis
DATE:    08/09/05 18:01:27 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

A.J. van der Horst (NASA/ORAU), V. Connaughton and M.S. Briggs (UAH)
report on behalf of the Fermi GBM Team:

"We have performed time-resolved spectroscopy of GRB 080825C (GCN 8141,
GCN 8183). The main emission up to 23 seconds is best fit by the Band
function. Time-resolved spectra of this emission period display the
commonly observed hard-to-soft spectral evolution, with Epeak decreasing
from 170 to 110 keV, while the spectral indices remain roughly constant
at alpha ~ -0.4 and beta ~ -2.4, consistent with the time-averaged
spectral result (GCN 8141).
Weaker emission following this period lasts a further 11 seconds and
deviates from this spectral behaviour. The spectrum of this tail over
the energy range 8-900 keV is best fit by a single power law with
index -1.41 +/- 0.09.

The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog."


GRB_name: GRB080905A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8185
SUBJECT: GRB 080905A: Swift-XRT Refined Analysis
DATE:    08/09/06 02:31:56 GMT
FROM:    Claudio Pagani at PSU/Swift-XRT  <pagani@astro.psu.edu>

C. Pagani and J. Racusin (PSU) report on behalf of the Swift-XRT team:

We have analyzed the first orbit of Swift-XRT data for the short GRB 080905A
(Pagani et al., GCN 8180) beginning at T0+130 seconds to T0+1.1 ks.

The enhanced XRT position given in GCN Circ 8180 is 40 arcseconds from the BAT
onboard position, within the BAT error circle.

The XRT lightcurve shows an initial count rate of approximately 6 counts/s for
the first 100 seconds of observations, followed by a steep decay and a
shallower phase. The decaying lightcurve can be fit with a broken power-law
with an initial decay index of 6.4+/-2.0, a break at approximately T0+400
seconds and a later decay index of 1.0+/-0.5.

The spectrum of 1 ks of Photon counting mode data from the first orbit can be
fit by an absorbed power-law with a photon index of 1.3+/-0.3 and absorption
consistent with the Galactic value along the line of sight (9e20 cm^-2,
Kalberla et al. 2005).  The average observed (unabsorbed) flux of the PC mode
data is 2.9e-9 (3.1e-10) ergs cm^-2 s^-1.

Assuming the X-ray emission continues to decline at the same rate, we predict a
0.3-10.0 keV XRT count rate of 0.001 counts/s at T+24hr, which corresponds to
an observed flux of 7e-14 ergs cm^-2 s^-1.

This Circular is an official product of the Swift-XRT team.


GRB_name: GRB080906A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8186
SUBJECT: GRB 080906: Swift detection of a burst with optical afterglow
DATE:    08/09/06 13:52:03 GMT
FROM:    David Burrows at PSU/Swift  <dxb15@psu.edu>

L. Vetere (PSU), S. D. Barthelmy (GSFC), P. J. Brown (PSU),
D. N. Burrows (PSU), M. M. Chester (PSU), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (CRESST/GSFC/USRA),
J. Mao (INAF-OAB), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
D. M. Palmer (LANL), J. L. Racusin (PSU),
B. Sbarufatti (INAF-IASFPA), M. Stamatikos (NASA/ORAU),
G. Tagliaferri (INAF-OAB), E. Troja (INAF-IASFPA) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 13:33:16 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080906 (trigger=323984).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 227.890, -80.486 which is 
   RA(J2000) = 15h 11m 34s
   Dec(J2000) = -80d 29' 09"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed one major peak
of duration ~50 sec, with possible smaller peaks.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~10 sec after the trigger. 

The XRT began observing the field at 13:34:27.6 UT, 71.3 seconds after
the BAT trigger. XRT found a bright, fading, uncatalogued X-ray source located
at RA, Dec 228.0514, -80.5183 which is equivalent to:
   RA(J2000)  = 15h 12m 12.3s
   Dec(J2000) = -80d 31' 05.8"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 150 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy. 


UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)
filter starting 82 seconds after the BAT trigger. There is a candidate
afterglow in the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  =  15:12:10.63 = 228.0443
  DEC(J2000) = -80:31:04.1  = -80.5178
with a 1-sigma error radius of about 0.5 arc sec. This position is 4.6 arc sec. 
from the center of the XRT error circle. The estimated magnitude is 19.7 with a
1-sigma error of about 0.5 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.30. 


GRB_name: GRB080905A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8187
SUBJECT: GRB 080905A, Swift-BAT refined analysis
DATE:    08/09/06 16:51:33 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), C. Pagani (PSU),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080905A (trigger #323870)
(Pagani, et al., GCN Circ. 8180).  The BAT ground-calculated position is
RA, Dec = 287.663, -18.865 deg, which is 
   RA(J2000)  =  19h 10m 39.1s 
   Dec(J2000) = -18d 51' 55.4" 
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 56%.
 
The mask-weighted light curve shows three peaks; the first two are partially
overlapping, starting at T+0.0 and ending at ~T+0.4 sec.  The third peak
starts at ~T+0.6 and ends at ~T+1.3 sec.  T90 (15-350 keV) is 1.0 +- 0.1 sec
(estimated error including systematics).
 
The time-averaged spectrum from T+0.0 to T+1.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.85 +- 0.24.  The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.04 sec in the 15-150 keV band
is 1.3 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/323870/BA/


GRB_name: GRB080905B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8188
SUBJECT: GRB 080905B, Swift-BAT refined analysis
DATE:    08/09/06 17:03:34 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), M. C. Stroh (PSU),
J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+903 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080905B (trigger #323898)
(Stroh, et al., GCN Circ. 8182).  The BAT ground-calculated position is
RA, Dec = 301.746, -62.568 deg, which is 
   RA(J2000)  =  20h 06m 59.1s 
   Dec(J2000) = -62d 34' 03.8" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 37%.
 
The mask-weighted light curve shows two clusters pf peaks. The first starts
at ~T-2 sec and almost returns to background levels as the second cluster
starts around T+40 sec.  The second cluster returns to background at ~T+220 sec.
T90 (15-350 keV) is 128 +- 16 sec (estimated error including systematics).
 
The time-averaged spectrum from T-15.5 to T+128.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.78 +- 0.15.  The fluence in the 15-150 keV band is 1.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+8.02 sec in the 15-150 keV band
is 0.5 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/323898/BA/


GRB_name: GRB080905B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8189
SUBJECT: GRB 080905B: Enhanced Swift-XRT position
DATE:    08/09/06 17:20:42 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 979 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 080905B, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 301.74122, -62.56313 which is equivalent
to:

RA (J2000): 20h 06m 57.89s
Dec (J2000): -62d 33' 47.3"

with an uncertainty of 1.7 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB080905A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8190
SUBJECT: GRB 080905A: NOT and VLT observations
DATE:    08/09/06 18:40:26 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@astro.ku.dk>

D. Malesani (DARK/NBI), A. de Ugarte Postigo (ESO), J. P. U. Fynbo 
(DARK/NBI), A. J. Levan (Univ. Warwick), E. Rol (Univ. Leicester), N. R. 
Tanvir (Univ. Leicester), C. C. Thoene (DARK/NBI), J. Telting (NOT), A. 
Baran (Cracow Univ.), report on behalf of a larger collaboration:

We observed the field of the short GRB 080905A (Pagani et al., GCN 8180) 
with the NOT and the VLT telescopes equipped with ALFOSC and FORS2, 
respectively. The NOT observations started on 2008 Sep 5.854 UT (8.51 hr 
after the GRB) and the total exposure time was 30 min. The VLT 
observations started on 2008 Sep 6.097 UT (14.3 hr after the GRB) and 
the total exposure was 40 min. All images were taken with the R filter.

Inside the XRT error circle, we detect a single, faint source with R ~ 
24 (against USNO-B1 stars), visible in both the NOT and VLT images. No 
variability of the source can be robustly determined, hence we cannot 
assess the relationship of this object with the GRB, especially given 
the relatively crowded field (Galactic latitude -12.6). Further 
observations are planned.

The coordinates of this object are:

RA(J2000) = 19:10:41.73
Dec(J2000) = -18:52:47.3

with an error of ~0.6".

We note that in our NOT images (seeing ~1"), the extended objects 
identified by Tristram et al. (GCN 8181) appear resolved into several 
pointlike sources.

Finding charts can be found at the following URL:

http://www.astro.ku.dk/~malesani/GRB/080905A

We acknowledge significant support from the observing staff at Paranal, 
in particular Swetlana Hubrig, Elena Mason and Andres Pino.


GRB_name: GRB080905B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8191
SUBJECT: GRB 080905B: VLT redshift
DATE:    08/09/07 00:16:14 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@astro.ku.dk>

Paul M. Vreeswijk, Johan P. U. Fynbo, Daniele Malesani, Jens Hjorth 
(DARK/NBI), Antonio de Ugarte Postigo (ESO), report on behalf of a 
larger collaboration:

We observed the field of GRB 080905B (Stroh et al., GCN 8182) with the 
ESO VLT equipped with FORS2. Several spectra were obtained with 
different grism choices, beginning on 2008 Sep 6.053  UT (8.34 hr after 
the GRB), and covering the wavelength ranges 3800-9500 AA at low to 
moderate resolution.

In the acquisition images, we clearly detect a point source inside the 
refined XRT error circle (Osborne et al., GCN 8189), at the coordinates 
(J2000):

RA = 20:06:57.90
Dec = -62:33:46.8

This position is consistent with that of the UVOT candidate afterglow 
reported by Stroh et al. (GCN 8182), the object being now significantly 
fainter (R ~ 20.2). We note that this position is 3.8" off the center of 
the bright 2MASS galaxy 2MASX J20065732-6233465, also visible in the DSS 
and in the UVOT images.

Spectroscopy of the afterglow reveals resonance absorption features from 
several ions, including OI, SiII, CIV, FeII, AlII, AlIII, MgII, MgI, at 
a redshift z = 2.374. The detection of transitions from fine-structure 
levels of FeII indicates that this is the redshift of the GRB, under the 
assumption that these levels are populated by GRB afterglow ultraviolet 
photons. We also find evidence for an intervening absorber at z = 1.438.

We acknowledge excellent support from the Paranal staff, in particular 
Elena Mason and Andres Pino.


GRB_name: GRB080905B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8192
SUBJECT: GRB 080905B: Refined UVOT Analysis
DATE:    08/09/07 00:43:31 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) & M. C. Stroh (PSU) report on behalf
of the Swift/UVOT team:

       The Swift/UVOT observed the field of GRB 080905B starting 94 s
after the BAT trigger (Stroh et al., 2008, GCNC. 8182).  Settled
observations started at T + 113 s.  We detect the optical afterglow
(Stroh et al., GCNC 8182) in the v and white filters at the
UVOT-enhanced location of the XRT afterglow (Osborne, et al., 2008,
GCNC 8089).  There is an uncertain detection in the b filter.  The
refined UVOT source position is

  RA (J2000) =  20:06:57.89
Dec (J2000) = -62:33:47.0

with an estimated uncertainty of 0.7 arcsec (radius, 90%
confidence).  We note that the afterglow is slightly blended with the
USNO-B1.0 star 274-094527, which makes it dificult to confirm the
detection in the b band.

     Magnitudes and upper limits are reported below.

Filter   TSTART   TSTOP     Exposure     Mag   Err  Comment
  white      113     213           98   18.70  0.09
    v        219     619          394   16.60  0.07
    b        699    6033          206   19.49  0.15  uncertain detection
    u        674    5828          216  >20.7         3-sigma upper limit
   uvw1      650    5623          197  >20.3         3-sigma upper limit
   uvm2     5218    5418          197  >19.9         3-sigma upper limit
   uvw2      729    6445          197  >20.5         3-sigma upper limit

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.05 mag (Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383,627).  The possible
detection in the b filter, coupled with the non-detections in the u,
uvw1, uvm2, and uvw2 filters, are consistent with a redshift of
approximately z < 3.3.  The power-law decay index in the v band
between 763 and 6505 s is -0.88.


GRB_name: GRB080905B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8193
SUBJECT: GRB 080905B: Swift-XRT Refined Analysis
DATE:    08/09/07 07:06:17 GMT
FROM:    Michael Stroh at PSU/Swift  <stroh@astroh.org>

M.C. Stroh (PSU) reports on behalf of the Swift-XRT team:

We have analyzed the Swift-XRT data obtained for GRB 080905B (Stroh et  
al., GCN Circ. 8182), totaling 85s of Windowed Timing and 10.2ks of  
Photon Counting data.

The 0.3-10 keV X-ray light-curve can be fit by a double broken power- 
law with an initial decay index of 2.46 +/- 0.18, second decay index  
of 0.01 +/- 0.18, and a third decay index of 1.41 +/- 0.4 with first  
and second break points at 258s and 2734s respectively. We predict  
counting rates of 7.88e-3 cts/s and 4.44e-3 cts/s at T+48 and T+72  
hours.

The spectrum from the Windowed Timing data can be fit with a power-law  
in excess of the Galactic value (3.5e20 cm-2, Kalberla et al. 2005),  
with an intrinsic column density of 1.32 (+0.57/-0.48)e22 cm^-2 and a  
photon index of 1.49 (+0.13/-0.12). The observed (unabsorbed) 0.3-10  
keV flux is 5.34e-10 (6.1e-10) ergs/cm^2/s.

The spectrum from the Photon Counting data can be fit with a power law  
with intrinsic column density of 2.26 (+0.53/-0.47)e22 cm^-2 and a  
photon index of 1.92 (+0.10/-0.10). The observed (unabsorbed) 0.3-10  
keV flux is 1.259e-10 (1.7e-10) ergs/cm^2/s.

This is an official product of the Swift-XRT team.


GRB_name: GRB080906A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8194
SUBJECT: GRB 080906: GROND observations of the optical/NIR afterglow
DATE:    08/09/07 09:44:25 GMT
FROM:    Paulo M. J. Afonso at MPE  <pafonso@mpe.mpg.de>

GRB 080906: GROND observations of the optical/NIR afterglow 

P.Afonso, T. Kruehler, J. Greiner, C.Clemens, A. Yoldas (all MPE Garching)
and A. Kuepcue Yoldas (ESO) report on behalf of the GROND team: 

We observed the field of GRB 080906 (Swift trigger 323984; L. Vetere et
al., GCN #8186), simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2m ESO/MPI telescope at La Silla 
Observatory (Chile). 

Observations started at 00:12 UT on September 7th, 2008, 10.7 hrs after
the GRB trigger.We detect the optical afterglow reported by  L. Vetere et
al. (GCN #8186) at a position consistent with the UVOT detection in all
bands, implying a redshift smaller than 3.5. 

Preliminary photometry yields the following magnitudes calibrated against
USNO-B1 and 2MASS field stars in stacked images: 

Band  Exp(min)   Mag 

g'    24         22.2 +- 0.1
r'    24         21.4 +- 0.1
i'    24         21.2 +- 0.1
z'    24         21.2 +- 0.1
J     20         20.2 +- 0.1
H     20         19.2 +- 0.1
K     20         18.5 +- 0.1 

not corrected for the expected Galactic foreground reddening of E(B-V) =
0.30 mag (Schlegel et al., 1998). 

 


GRB_name: GRB080905A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8195
SUBJECT: GRB 080905A: optical afterglow
DATE:    08/09/07 10:35:30 GMT
FROM:    Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@astro.ku.dk>

A. de Ugarte Postigo (ESO), D. Malesani (DARK/NBI), A. J. Levan (Univ. 
Warwick), J. Hjorth (DARK/NBI), N. R. Tanvir (Univ. Leicester), report 
on behalf of a larger collaboration:

We observed again the field of the short GRB 080905A (Pagani et al., GCN 
8180) with the ESO VLT equipped with FORS2. R-band observations were 
carried out starting on 2008 Sep 7.004 UT (1.50 days after the GRB) and 
the total exposure time was 40 minutes.

The object located inside the XRT error circle visible in our early VLT 
images (Malesani et al., GCN 8190) has clearly faded between the two 
observations, and is thus likely the optical afterglow of GRB 080905A. 
We note that this object is located outside the revised 2.2"-radius 
(90%) UVOT-enhanced XRT error circle (distance from center 4.6"), as 
provided at http://www.swift.ac.uk/xrt_positions/index.php (value of Sep 
7.4 UT).

In our second epoch image, which is deeper and has a better seeing 
(~0.9"), we also note the presence of a bright extended object, possibly 
a spiral galaxy, about 9" S, 3" E of the afterglow (partially covered by 
foreground stars).

Finding charts can be found at

http://www.astro.ku.dk/~malesani/GRB/080905A/#epoch2

We acknowledge significant support from the ESO observing staff at 
Paranal, in particular Elena Mason, Andres Pino and Swetlana Hubrig.


GRB_name: GRB080906A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8196
SUBJECT: GRB 080906, Swift-BAT refined analysis
DATE:    08/09/07 17:40:23 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
J. Tueller (GSFC), T. Ukwatta (GWU), L. Vetere (PSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080906 (trigger #323984)
(Vetere, et al., GCN Circ. 8186).  The BAT ground-calculated position is
RA, Dec = 228.055, -80.540 deg, which is 
   RA(J2000)  =  15h 12m 13.3s 
   Dec(J2000) = -80d 32' 24.9" 
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 58%.
 
The mask-weighted light curve shows a roughly symmetrical peak starting
at ~T-100 sec, peaking around T+10 sec, and tailing off to about T+100 sec.
T90 (15-350 keV) is 147 +- 21 sec (estimated error including systematics).
 
The time-averaged spectrum from T-105 to T+104 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.59 +- 0.09.  The fluence in the 15-150 keV band is 3.5 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band
is 1.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/323984/BA/


GRB_name: GRB080906A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8197
SUBJECT: GRB 080906: Swift-XRT Refined Analysis
DATE:    08/09/07 20:20:43 GMT
FROM:    Loredana Vetere at PSU  <vetere@astro.psu.edu>

L. Vetere, J.L. Racusin, C. Pagani (PSU), J.P. Osborne, A.P. Beardmore,
P.A. Evans and M.R. Goad (U. Leicester)  report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 080906 (trigger=323984; Vetere et al.,
GCN Circ 8186) at 13:34:27.6 UT, 71.3 seconds after the BAT trigger.

Using 1224 s of XRT Photon Counting mode data and 2 UVOT images, we find an
astrometrically corrected X-ray position (using the XRT-UVOT alignment and
matching to the USNO-B1 catalogue): RA, Dec = 228.04211, -80.51787 which is
equivalent to:

 RA (J2000): 15 12 10.11
 Dec (J2000): -80 31 04.3

 with an uncertainty of 1.8 arcsec (90% confidence).

This position may be improved as more data are received. The latest position can
be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described
by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf),
the current algorithm is an extension of this method.

This position is 80 arcsec away from the ground-processed BAT position given in
GCN Circ. 8196 (Stamatikos et al.) inside BAT error circle.


The WT mode lightcurve shows a number of flares, with the strongest peaking
around
186, 598 and 907 s after the trigger. The PC data in later orbits  shows some
flaring activity and decays as a single power-law  with alpha = 1.25 +/- 0.11.

The WT spectrum of the first 80 s (before the first peak) can be fitted with a
power-law of Gamma = 1.82 +/-0.08 and absorption consistent with the Galactic
value
along the line of sight (9.7x10^20 cm^-2). The observed (unabsorbed) flux over
this
time is 1.98 (2.7)x10^-9 erg cm^-2 s^-1. A spectrum extracted from the PC mode
data
(11.6-75.6 ks after the trigger) can be fitted with a power-law of Gamma = 2.3
+0.1/-0.2
and total NH = (1.7 +/- 0.5)x10^22 cm^-2, slightly in excess of the Galactic
value.
The observed (unabsorbed) flux over this time is 1.7 (3.1)x10^-11 erg cm^-2
s^-1.

If the decay continues with alpha = 1.25, the predicted count-rate at 48 hours
is
0.007 count s^-1, corresponding to an observed (unabsorbed) flux of 2.6
(4.8)x10^-13
erg cm^-2 s^-1.


This Circular is an official product of the Swift-XRT team.


GRB_name: GRB080906A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8198
SUBJECT: GRB 080906: Refined Swift/UVOT Observations
DATE:    08/09/07 22:00:22 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/USRA/GSFC) & L. Vetere (PSU) report on behalf of
the Swift/UVOT team:

       The Swift/UVOT observed the field of GRB 080906 starting 62 s
after the BAT trigger (Vetere et al., 2008, GCNC. 8186).  Settled
observations started at T + 82 s.  We detect the optical afterglow
(Vetere et al., GCNC 8186) in the v, b, u, and white filters.  The
refined UVOT source position is

  RA (J2000) =  15:12:10.65
Dec (J2000) = -80:31:03.2

with an estimated uncertainty of 0.64 arcsec (radius, 90% confidence).

     Magnitudes and upper limits are reported below.

Filter   TSTART   TSTOP   Exposure     Mag  Err  Comment
  white       82     182         98   19.71 0.15
    v        188     588        393   18.61 0.12
    b        668    6204        216   21.02 0.44
    u        643    5998        236   20.37 0.34
   uvw1      619    5793        236  >20.9        2-sigma upper limit
   uvm2      594    5588        236  >20.5        2-sigma upper limit
   uvw2      698    6614        235  >21.1        2-sigma upper limit

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.30 mag (Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383,627).

      The detection in the u filter, coupled with the non-detections in
the uvw1, uvm2, and uvw2 filters, are consistent with a redshift of
approximately z < 2.6.  The power-law decay index in the v band
between 338 and 6719 s is -0.50 +/- 0.04.

Please update my e-mail address in your Address Book to <Stephen.T.Holland@nasa.gov 
 >.
/
\
/


GRB_name: GRB080905A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8202
SUBJECT: GRB 080905A: MITSuME Akeno optical upper limits
DATE:    08/09/08 13:33:19 GMT
FROM:    Nobuyuki Kawai at Tokyo Tech  <nkawai@hp.phys.titech.ac.jp>

H. Nakajima, T. Shimokawabe, Y.A. Mori, Y. Kudou, and N. Kawai (Tokyo  
Tech) report on behalf of the MITSuME collaboration:

We performed optical imaging observation of the field of GRB 080905A
(C. Pagani et al. GCN 8180) with the 3-color 50cm MITSuME Telescope at
Akeno, Japan from 12:40:12 UT (42min after the trigger) to 14:32:07 UT.
In the co-added images of Ic, Rc, and g' bands, we did not detect any
afterglow candidate in the XRT error circle. The 3-sigma limiting
magnitudes based on USNO-B1.0 (I-band) and NOMAD (R-band,g'-band)
stars are following:

Filter Start(UT) End(UT)  Exposure   LimitMag
---------------------------------------------------
g'     12:40:12  13:14:31 30 x 60 s  17.1
Rc     12:40:12  13:14:31 30 x 60 s  17.6
Ic     12:40:12  13:14:31 30 x 60 s  17.6
---------------------------------------------------


GRB_name: GRB080905A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8203
SUBJECT: GRB 080905A: Enhanced Swift-XRT position
DATE:    08/09/08 15:06:05 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, J.P. Osborne and M.R. Goad (U. Leicester) report on behalf
of the Swift-XRT team:

Using more data than were available at the time of de Ugarte Postigo et
al. (GCN Circ 8195), the UVOT-enhanced X-ray position of GRB 080905A has
been improved to RA, Dec = 287.67390, -18.88022 which is equivalent to:

RA (J2000): 19 10 41.74
Dec (J2000): -18 52 48.8

with an uncertainty of 1.6 arcsec (90% confidence). This position lies
1.5" from the optical counterpart identified by Malesani et al (GCN
Circ. 8190), consistent with that position.

Position enhancement, using the XRT-UVOT alignment and matching to the
USNO-B1 catalogue, is described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is
an extension of this method.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB080905A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8204
SUBJECT: GRB 080905A: Fermi Gamma-ray Burst Monitor detection
DATE:    08/09/09 12:03:02 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi, S. McBreen (MPE), V. Connaughton (UAH) and 
A. von Kienlin (MPE) report on behalf of the 
Fermi Gamma-ray Burst Monitor Team: 



"At 11:58:55 UT on 5 September 2008, the Fermi GBM triggered 
and located GRB 080905A (trigger 242308736 / 080905499), which was 
also detected by Swift (Pagani et al., GCN 8180). The on-ground 
calculated location, using the Fermi GBM trigger data, is 
RA = 286.3, Dec = -18.2 (J2000 degrees) (equivalent to J2000 
19h 05m, -18d 12'), with a statistical uncertainty of 4.6 degree 
(radius, 1-sigma containment; there is additionally a systematic 
error which is currently estimated to be 2 to 3 degrees). 
This position is 1.5 deg from the Swift refined position
(Evans et al., GCN 8203). The angle from the Fermi LAT boresight 
to the Swift position is 28 degrees.

This short GRB consists of two peaks, the first from T0 to
T0+0.4 sec and the second from T0+0.6 sec to T0+1.1 sec.
The first peak shows substructure in agreement with 
the Swift-BAT refined analysis (J. Cummings et al., GCN 8187).
T90 (50-300 keV) is about 1 sec.

The time-averaged spectrum from T0 to T0+1 sec is well fit 
by a power law function with index -0.96 +/- 0.05.
The fluence (50-300 keV) is 2.8(+/-0.2)E-07 erg/cm2
and the peak flux (50-300 keV) is 6.1 +/- 0.8 ph/cm2/s.


The spectral analysis results presented above are preliminary; 
final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB080905B
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8205
SUBJECT: GRB 080905B: Fermi Gamma-ray Burst Monitor detection
DATE:    08/09/09 18:15:32 GMT
FROM:    Narayana Bhat at U Alabama/Huntsville/GBM  <Narayana.Bhat@nasa.gov>

P. N. Bhat (UAH), W. Paciesas (UAH) and A.J. van der Horst (NASA/ORAU)
report on behalf of the Fermi Gamma-ray Burst Monitor Team:


"At 16:55:46 UT on 5 September 2008, the Fermi GBM triggered
and located GRB 080905B (trigger 242326547 / 080905705), which was
also detected by Swift (Stroh et al., GCN 8182). The on-ground calculated
location, using the Fermi GBM trigger data, is RA = 307.1, Dec = -60.2
(J2000 degrees) (equivalent to J2000 20h 28m, -60d 12'), with a statistical
uncertainty of 5.7 degree (radius, 1-sigma containment; there is
additionally a systematic error which is currently estimated to be 2 to 3
degrees). The angle from the Fermi LAT boresight to the GBM localization
is 82 degrees. 

This long GRB consists of one main peak at trigger time, possibly a weak
pre-trigger at T-20 s and second peak at T0 + 70 sec and the third from
T0+80 sec to T0+110 sec similar to the Swift light curve.

The burst duration (in the energy range 20-1000 keV) T90 is about 159 sec.

The time-averaged spectrum from T0-20 to T0+110 sec is well fit by a power
law function with index -1.75 +/- 0.12.The fluence (20-1000 keV) is
4.1(+/-0.3)E-08 erg/cm2and the peak flux (20-1000 keV) is 0.21 +/- 0.02
ph/cm2/s.

The spectral analysis results presented above are preliminary;
final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB080904A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8206
SUBJECT: GRB 080904:  Fermi Gamma-ray Burst Monitor detection
DATE:    08/09/10 01:52:43 GMT
FROM:    Valerie Connaughton at MSFC  <valerie@nasa.gov>

Valerie Connaughton (UAH) and Alexander van der Horst (NASA/MSFC), 
report on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 21:16:10 UT on 04 September 2008, the Fermi Gammay-Ray Burst Monitor
(GBM) triggered and located a soft GRB 080904 (trigger 242255765 /
080904.886). The on-ground calculated location, using the GBM trigger
data, is RA = 215.1, Dec = -32.3 (J2000 degrees) (equivalent to J2000
14h 20m, -32d 18m), with an uncertainty of 1.4 degrees (radius, 1-sigma
containment, statistical only; there is additionally a systematic error
which is currently estimated to be 2 to 3 degrees).  The angle from the
Large Area Telescope (LAT) boresight is 23 degrees.

This GRB was about 22 s long with 1 peak, showing some substructure on
the pulse rise.   The time-averaged spectrum from T-4 to T+17 s is best
fit by a Band function with the following parameters:
alpha= 0.0 +/- 0.17
beta = -2.70 +/- 0.08
Epeak = 35 +/- 1 keV

The fluence between 50 and 300 keV over these 21 seconds is 2.25 +/-
0.49 x 10^-6 erg/cm^2 with a peak flux of 3.5 +/- 0.7 photons/cm^2/sec.
Between 15 and 150 keV the peak flux is 12.7 +/- 2.7 photons/cm^2/sec.

According to the prescription of Sakamoto et al. 2008 (ApJ, 679, 570),
the ratio of the fluences in the 25-50 keV and 50-100 keV energy
ranges of 1.37 +/- 0.36 puts this in the X-Ray Flash category (XRF)
but the error bar allows it to be considered, alternatively,
an X-Ray Rich event (XRR).

The spectral analysis results presented above are preliminary; the
final results will be published in the GBM GRB Catalog."


GRB_name: GRB080905B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8207
SUBJECT: GRB 080905B: Watcher optical detection
DATE:    08/09/10 12:26:32 GMT
FROM:    John French at UCD,Ireland  <jfrench@bermuda.ucd.ie>

John French (UCD School of Physics, DARK/NBI), Gary Melady (UCD School of Physics), Daniele Malesani, Paul Vreeswijk (DARK/NBI) report on behalf of
a larger collaboration:

The Watcher 40 cm robotic telescope at Boyden Observatory, South Africa, began imaging the field of GRB 080905B (Stroh et al al. GCN 8182) at
16:56:28 UT, 43 s after the Swift triggger. In a stacked sequence of 10 unfiltered 10 s exposures, with a mid-time of 16:57:37 UT (112 s after the
Swift trigger), we detect a point source inside the refined XRT error circle (Osborne et al. GCN 8189), at a position consistent with the
detections reported by Holland et al. (GCN 8192) , Vreeswijk et al. (GCN 8191) and Stroh et al. (GCN 8182).

We measure a magnitude of 16.2 +/- 0.2 for the source, based on comparison with the USNO-B1 star at RA 20:06:51.361, Dec -62:32:52.55. Further
analysis is ongoing.


GRB_name: GRB080905A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8208
SUBJECT: GRB080905A: Swift/UVOT Upper Limits
DATE:    08/09/10 13:18:20 GMT
FROM:    Peter Brown at PSU  <pbrown@astro.psu.edu>

P. J. Brown and C. Pagani (PSU) report on behalf of the Swift/UVOT team:

The Swift/UVOT observed the field of GRB 080905A
starting about 114 s after the BAT detection
(Pagani et al., GCN Circ. 8180).  We do not detect
any source in the revised XRT error circle (Evans et
al., GCN Circ. 8203) including the faint optical afterglow
seen by Malesani et al. (GCN Circ. 8190)
in any of the UVOT filters down to the following 3 sigma
upper limits (where T_start and T_stop represent the
elapsed time since the BAT trigger in seconds).

Filter  T_start(s) T_stop  Exp(s)   MagLimit
white   114        970     198      >21.3
uvw2    730        750     19       >18.1
uvm2    626        4520    95       >19.2
uvw1    651        825     39       >18.8
u       675        850     39       >19.2
b       700        865     15       >18.9
v       220        1250    1014     >20.6

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E(B-V) = 0.14 mag (Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383,627).


GRB_name: GRB080905B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8210
SUBJECT: GRB 080905B: Photometric Redshift for the 2MASS Galaxy
DATE:    08/09/10 13:45:38 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

Stephen Holland (CRESST/USRA/GSFC) reports, on behalf of the
Swift/UVOT team:

      We have performed UVOT photometry on the 2MASS galaxy 2MASX
J20065732-6233465 galaxy located 4 arcsec from the optical afterglow
of GRB 080905B (Stroh et al., 2008, GCNC 8182).  Our magnitudes are:

Filter    Mag  Err
    v    17.85 0.05
    b    18.70 0.05
    u    18.46 0.05
  uvw1   18.76 0.07
  uvm2   18.71 0.07
  uvw2   18.76 0.07

These magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E_{B-V} = 0.05 mag (Schlegel et al.,
1998, ApJS, 500, 525) along this line of sight.  The photometry is on
the UVOT photometric system described in Poole et al. (2008, MNRAS,
383,627).

      The detection in the uvw2 filter implies that the redshift of the
2MASS galaxy can not be greater than approximately z = 1.7.    This is
inconsistent with the VLT redshift of z = 2.374 for the afterglow
(Vreeswijk, et al., 2008, GCNC 8191).  This suggests that the 2MASS
galaxy is not the host galaxy of GRB 080905B.


GRB_name: GRB080905C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8213
SUBJECT: GRB 080905C: Fermi GBM detection
DATE:    08/09/11 15:08:30 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi, S. McBreen and A. von Kienlin (MPE) 
report on behalf of the Fermi GBM Team: 



"At 13:41:29 UT on 5 September 2008, the Fermi Gamma-ray Burst Monitor  
triggered and located GRB 080905C (trigger 242314890 / 080905570).
The on-ground calculated location, using the Fermi GBM trigger 
data, is RA = 96.9, Dec = -69.8 (J2000 degrees) 
(equivalent to J2000 06h 28m, -69d 48'), 
with a statistical uncertainty of 8 degrees (radius, 1-sigma
containment; there is additionally a systematic error which is 
currently estimated to be 2 to 3 degrees). The angle from the 
Fermi LAT boresight is 108 degrees. 

This event comprises three pulses beginning at T0-4 s. 
The main emission occurs during the first 11 sec and T90 (50-300 keV)
is about 28 s. The time-averaged spectrum from T0-3.6 s to T0+17 s
is adequately fit by a power law function with an exponential
high energy cutoff. The power law index is -0.90 +/-0.17 and
the cutoff energy, parameterized as Epeak, is 78.8 +/- 5.9 keV.

The fluence (25-1000 keV) is 4.6 (+/-0.3)E-06  erg/cm2
and the peak flux (25-1000 keV) on the 128 ms timescale 
is 4.4 +/- 1.9 ph/cm2/s.


The spectral analysis results presented above are preliminary; 
the final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB080906B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8214
SUBJECT: GRB 080906B: Fermi GBM detection
DATE:    08/09/11 16:01:22 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi, S. McBreen and A. von Kienlin (MPE) 
report on behalf of the Fermi GBM Team: 




"At 05:05:11 UT on 6 September 2008, the Fermi Gamma-ray Burst Monitor
triggered and located GRB 080906B (trigger 242370312 / 080906212).
The on-ground calculated location, using the Fermi GBM 
trigger data, is RA = 185.5, Dec = -8.6 (J2000 degrees) 
(equivalent to J2000 12h 22m, -08d 36'), 
with a statistical uncertainty of 3.3 degrees (radius, 1-sigma 
containment; there is additionally a systematic error which is 
currently estimated to be 2 to 3 degrees). The angle from the 
Fermi LAT boresight is 32 degrees. 

This GRB consists of one main emission phase comprising
several overlapping pulses, with an estimated T90 (50-300 keV) 
of about 5 s. The time-averaged spectrum from T0 to T0+3.8 s is 
best fit by a Band function with the following parameters:
alpha = -0.07 +/- 0.09             
beta = -2.10 +/- 0.07             
Epeak = 125.3 +/- 6.6 keV         

The fluence (25-1000 keV) is 10.9 (+/-0.1)E-06 erg/cm2.
The peak flux (25-1000 keV) on the 128 ms timescale
is 22 +/- 4 ph/s/cm2.



The spectral analysis results presented above are preliminary;
the final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB080906A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8216
SUBJECT: GRB 080906: Watcher observations
DATE:    08/09/12 13:41:43 GMT
FROM:    Alejandro Ferrero at U College,Dublin  <alejandro.ferrero@ucd.ie>

Alejandro Ferrero (UCD School of Physics), John French (UCD School of
 Physics, DARK/NBI), Gary Melady (UCD School of Physics) report on
 behalf of a larger collaboration:
 
 The Watcher 40 cm robotic telescope at Boyden Observatory, South
 Africa, began imaging the field of GRB 080906 (Vetere et al. GCN 8186)
 at 16:51:15.5 UT, 3.6 h after the Swift triggger. We do not detect the
 afterglow reported by Holland et al. (GCN 8198) and Afonso et al. (GCN
 8194). Our first 120s exposure has a limiting magnitude of 16.9, while
 a stacked sequence of 10 120s images, with an exposure mid-time of 3.8
 hrs after the trigger, results in a limiting magnitude of 18.4.
 Unfiltered magnitudes are transformed to R-band by comparison with the
 USNO-B1 catalog.


GRB_name: GRB080913A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8217
SUBJECT: GRB 080913: Swift detection of a burst
DATE:    08/09/13 07:03:29 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

P. Schady (MSSL-UCL), A. P. Beardmore (U Leicester),
J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester),
O. Godet (U Leicester), C. Gronwall (PSU),
C. B. Markwardt (CRESST/GSFC/UMD), K. L. Page (U Leicester),
D. M. Palmer (LANL), A. M. Parsons (GSFC), D. Perez (U Leicester),
R. L. C. Starling (U Leicester) and E. Troja (INAF-IASFPA) report on
behalf of the Swift Team:

At 06:46:54 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080913 (trigger=324561).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 65.725, -25.110 which is 
   RA(J2000) = 04h 22m 54s
   Dec(J2000) = -25d 06' 36"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure with a duration of about 10 sec.  The peak count rate
was ~800 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 06:48:33.6 UT, 99.5 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 65.72800,
-25.12945 which is equivalent to:
   RA(J2000)  = 04h 22m 54.72s
   Dec(J2000) = -25d 07' 46.0"
with an uncertainty of 2.4 arcseconds (radius, 90% containment). This
location is 70 arcseconds from the BAT onboard position, within the BAT
error circle. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
3.17e+20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm)  filter starting 105 seconds after the BAT trigger. No
afterglow candidate has  been found in the initial data products. The
2.7'x2.7' sub-image covers 25% of  the BAT error circle and 100% of
the XRT error circle. The 3-sigma upper limit at the XRT position is
20.7 mag.  The 8'x8' region for the list of sources generated
on-board covers 100% of the  BAT error circle. The list of sources is
typically complete to about 18 mag. No  correction has been made for
the expected extinction corresponding to E(B-V) of  0.04. 

Burst Advocate for this burst is P. Schady (ps AT mssl.ucl.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080913A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8218
SUBJECT: GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
DATE:    08/09/13 09:07:05 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

A. Rossi (Tautenburg Obs.), J. Greiner, T. Kruehler, A. Yoldas (all MPE), 
S. Klose (Tautenburg Obs.), A. Kuepcue Yoldas (ESO)
report on behalf of the GROND team: 

We observed the field of GRB 080913 (Swift trigger 324561; Schady et
al., GCN #8217), simultaneously in g'r'i'z'JHK with GROND (Greiner et al.
2008, PASP 120, 405) mounted at the 2.2m ESO/MPI telescope at La Silla 
Observatory (Chile). Observations started at 06:50 UT on September 13, 2008, 
3 min after the GRB trigger. We detect a faint optical object inside
the 2.4 arcsec Swift/XRT error box (Schady et al., GCN #8217).

We detect the object only in the z'-band and NIR, but not in i'-band
or bluer. Preliminary photometry yields the following magnitudes calibrated 
against USNO-B1 and 2MASS field stars in stacked images: 
r' > 23.2 mag,
i' > 23.0 mag,
z' = 22.4 mag,
not corrected for the expected Galactic foreground reddening of E(B-V) =
0.05 mag (Schlegel et al., 1998). 

The non-detection in i' and bluer may indicate a redshift of about 6.
We caution however, that the drop-out is only 0.6 mag in depth between
our i' and z' bands, and our lack of better sensitivity could make this
a wrong interpretation. We encourage deeper observations.

 


GRB_name: GRB080913A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8219
SUBJECT: GRB 080913: Enhanced Swift-XRT position
DATE:    08/09/13 09:10:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2223 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 080913, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 65.72775, -25.12950 which is equivalent
to:

RA (J2000): 04h 22m 54.66s
Dec (J2000): -25d 07' 46.2"

with an uncertainty of 1.9 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB080913A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8220
SUBJECT: GRB 080913: REM NIR early observations
DATE:    08/09/13 09:58:37 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo, S. Covino, L.A. Antonelli, D. Malesani, D. Fugazza, L.  
Calzoletti,  S. Campana, G.  Chincarini, M.L. Conciatore, S. Cutini, V. 
D'Elia,  F. D'Alessio, F.  Fiore, P. Goldoni, D. Guetta,  C. Guidorzi, 
G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E. Meurs, L. 
Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L.  Stella, G.  Stratta, 
G. Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F. Vitali report on 
behalf of the REM team:

The robotic 60-cm REM telescope located at La Silla (Chile) observed 
automatically the field of the GRB 080913 (Schady et al. GCN 8217) on 
Sep 13 starting about 6 min after the burst.  Observations were carried 
out at high airmass. Coadding a series of 10s, 30s and 60s exposures, at 
a mean t-t0 ~ 40 min we do not see the object reported by Rossi et al. 
(GCN 8218) or any other afterglow candidate inside the refined XRT error 
box (Beardmore et al.; GCN 8219) down to J > 17.1, H > 17.2 and K > 15.8 
(3sigma c.l.).


GRB_name: GRB080913A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8221
SUBJECT: GRB 080913: VLT/FORS2 observations
DATE:    08/09/13 10:58:48 GMT
FROM:    Paul Vreeswijk at Dark Cosmology Centre,U.of Copenhagen  <pmv@dark-cosmology.dk>

P.M. Vreeswijk, J.P.U. Fynbo, D. Malesani (DARK/NBI) report on behalf 
of a larger collaboration:

The field of GRB 080913 (Swift trigger 324561; Schady et al., GCN 
#8217) was observed in target-of-opportunity mode with VLT+FORS2 using 
the imaging sequence RzIVBR, starting at 7:31 UT on September 13, 2008, 
i.e. 45 minutes after the GRB.

In the z-band image a faint source is detected within the Swift/XRT 
error circle, with magnitude z(AB) = 23.1 (based on a very preliminary 
calibration), while this object is not detected in any of the other 
optical filters. Comparison with the z-band magnitude reported by Rossi 
et al. (GCN #8218) suggests that the object has faded between 3 and 45 
minutes after the burst, and therefore is likely the afterglow of GRB 
080913.

We are very grateful for the excellent support by the Paranal 
observatory staff, in particular Rachel Gilmour and Heidi Korhonen.

[GCN OPS NOTE(06nov08): Per author's request, "Heidi Schmidt" was
changed to "Hiedi Korhonen".]


GRB_name: GRB080913A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8222
SUBJECT: GRB 080913, Swift-BAT refined analysis
DATE:    08/09/13 16:07:01 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc@milkyway.gsfc.nasa.gov>

M. Stamatikos (GSFC/ORAU),  S. D. Barthelmy (GSFC),  W. Baumgartner 
(GSFC/UMBC),
J. Cummings (GSFC/UMBC),  E. Fenimore (LANL),  N. Gehrels (GSFC),
H. Krimm (GSFC/USRA),  C. Markwardt (GSFC/UMD),  K. McLean (GSFC/UMD),
D. Palmer (LANL),  A. Parsons (GSFC),  T. Sakamoto (GSFC/UMBC),  G. Sato 
(ISAS),
P. Schady (MSSL-UCL),  J. Tueller (GSFC),  T. Ukwatta (GWU)

(i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry 
downlink,
we report further analysis of BAT GRB 080913 (trigger #324561) (Schady, 
et al.,
GCN Circ. 8217).  The BAT ground-calculated position is
RA, Dec = 65.741, -25.127 deg which is
  RA(J2000)  =  04h 22m 57.9s
  Dec(J2000) = -25d 07' 38.6"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 39%.

The mask-weighted light curve shows multiple overlapping peaks, somewhat
smooth in character.  T90 (15-350 keV) is 8 +- 1 sec (estimated error
including systematics).

The time-averaged spectrum from T-3.8 to T+5.2 sec is best fit by a 
power law
with an exponential cutoff.  This fit gives a photon index 0.46 +- 0.70,
and Epeak of 93.1 +- 56.1 keV (chi squared 38.53 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 5.6 +- 0.6 x 10-07 
erg/cm2
and the 1-sec peak flux measured from T+0.11 sec in the 15-150 keV band is
1.4 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.36 +- 0.15 (chi squared 44.56 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/324561/BA/


GRB_name: GRB080913A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8223
SUBJECT: GRB 080913: GROND photo-z
DATE:    08/09/13 16:39:12 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

J. Greiner, T. Kruehler (both MPE), A. Rossi (Tautenburg Obs.)
report on behalf of the GROND team: 

We have analyzed more data of our GROND observing run (Rossi et al. 2008, 
GCN #8218) of GRB 080913 (Schady et al. 2008, GCN #8217; Stamatikos et al. 
2008, GCN #8222). The object reported previously is clearly detected in 
several epochs. The position is

RA (2000.0) = 04:22:54.74 
Decl. (2000.) = -25:07:46.2

with an uncertainty of 0.5 arcsec. This position is consistent with the 
astrometrically corrected Swift X-ray position (Beardmore et al. 2008, 
GCN #8219).

z'-band data spanning the time period from 3 min to 3 hrs after the burst
clearly show a fading source and are well fit with a power law
of decay slope 0.6 +- 0.3. This confirms the fading seen with the VLT
(Vreeswijk et al. 2008, GCN #8221). If this fading continues, we predict
z(AB) ~ 25 mag at 24 hrs after the GRB.

The afterglow is detected in z'JHK, but not in g'r'i-bands. After
correction for foreground extinction of A_V=0.129, we obtain (AB system)
g > 23.3 +- 0.1
r > 23.3 +- 0.1
i > 23.0 +- 0.1
z = 22.52 +- 0.15
J = 20.90 +- 0.06
H = 20.67 +- 0.09
K = 20.54 +- 0.21
at 07:13 UT (mid-time of 12 min exposure), 26 min after the GRB.
A fit to this simultaneously obtained 7-filter spectral energy distribution, 
using Hyper-z (Bolzonella et al. 2000) results in a photometric redshift of
z = 6.44 +- 0.3. The SED-fit is shown on http://www.mpe.mpg.de/~jcg/grb080913.html


GRB_name: GRB080913A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8224
SUBJECT: GRB080913: Swift/UVOT Upper Limits
DATE:    08/09/13 16:40:12 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates and P. Schady report on behalf of the Swift/UVOT team.

The Swift/UVOT began settled observations of the field of GRB 080913 
starting
105s after the BAT trigger (Schady et al., GCN 8217). We do not detect an
afterglow in any of the UVOT filters inside the UVOT-enhanced XRT
error circle (Beardmore et al., GCN 8219).

The 3 sigma upper limits for the finding charts (fc) and summed images
are given below:

Filter    T_start(s)  T_stop(s)  Expo(s)  Magnitude (3 sigma UL)
-----------------------------------------------------------------
White (fc)   105        205        98           >20.92
White        105       1964        238          >21.26                 
v (fc)       211        611        393          >20.08
v            211       1858        865          >20.39
b            691       1957        97           >19.62
u            666       1932        117          >19.36
w1           641       1907        117          >19.48
m2           616       1882        78           >18.84
w2           721       1833        58           >18.99
----------------------------------------------------------------

The above magnitudes are not corrected for the Galactic extinction 
corresponding to a
reddening of E_{B-V} = 0.04 mag (Schlegel et al., 1998, ApJS, 500, 525). 
The photometry
is on the UVOT flight system described in Poole et al. 
(2008,MNRAS,383,627).


GRB_name: GRB080913A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8225
SUBJECT: GRB 080913: VLT/FORS spectrum
DATE:    08/09/13 17:28:26 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

J.P.U. Fynbo (DARK/NBI), J. Greiner, T. Kruehler (both MPE),
A. Rossi (Tautenburg Obs), P. Vreeswijk, D. Malesani (both DARK/NBI)
report on behalf of a larger collaboration

Based on the rapid determination of an i'-band drop out we triggered 
VLT/ToO observations (program-ID 081.A-0135; PI Greiner) and obtained 
spectroscopy with FORS2+Gris600z of the afterglow of GRB080913
(Schady et al. 2008, GCN #8217; Stamatikos et al. 2008, GCN #8222). 
Observations started at 8:30, about 100 min after the GRB, and continued
until morning twilight. We detect a red continuum that disappears
bluewards of a break around 9400 AA. Interpreting this break
as the onset of the Lyman-alpha forest we infer a redshift
of about z=6.7 consistent with the photometric redshift determined
by GROND  (Greiner et al., GCN #8223).

We are very grateful for the excellent support by the Paranal
observatory staff, in particular Rachel Gilmour and Heidi Korhonen.

[GCN OPS NOTE(06nov08): Per author's request, "Heidi Schmidt" was
changed to "Hiedi Korhonen".]


GRB_name: GRB080913A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8226
SUBJECT: GRB 080913: Swift-XRT refined analysis
DATE:    08/09/13 17:30:12 GMT
FROM:    Andy Beardmore at U Leicester  <apb@star.le.ac.uk>

A.P. Beardmore (U. Leicester) and P. Schady (MSSL-UCL) report on behalf
of the Swift-XRT team :

The Swift-XRT started observing the field of GRB 080913 (trigger number 
324561, Schady et al., GCN Circ. 8217) at 2008-09-13 06:48:30 UT, 94 s
after the trigger. The best XRT position is the UVOT-enhanced position
reported by Beardmore et al. (GCN Circ. 8219).

The X-ray light curve presently spans 5 orbits of photon counting mode
data from T+108 s to T+23 ks. The light curve shows a number of small
flares in the first orbit, with the largest giving a factor of ~7 
increase in count rate at T+1.8 ks, on top of a power-law decay of 
index 1.20 +0.16 -0.13.

A 2.7 ks exposure X-ray spectrum from T+108 s to T+7.6 ks can be well 
fit by an absorbed power-law with a photon index of 1.69 +0.46 -0.41 
and a column density consistent with the Galactic value of 3.2 x 10^20 cm^-2 
in the direction of the burst.  The observed  0.3-10.0 keV flux is 
(3.2 +0.9 -1.6) x 10^-12 erg cm^-2 s^-1 which corresponds to an unabsorbed 
flux of (3.7 +1.6 -1.7) x 10^-12  erg cm^-2 s^-1. The count to flux 
conversion factor is 4.6 x 10^-11 erg cm^-2 count^-1.

Providing the source continues to decay at the same rate, we predict a
count rate of 2.8 x 10^-4 count s^-1 at T+1 day.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB080915A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8227
SUBJECT: GRB 080915: Swift detection of a burst
DATE:    08/09/15 00:14:56 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

S. R. Oates (UCL-MSSL), A. P. Beardmore (U Leicester),
J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester),
C. Gronwall (PSU), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL), A. M. Parsons (GSFC),
R. L. C. Starling (U Leicester) and T. N. Ukwatta (GSFC/GWU) report
on behalf of the Swift Team:

At 00:02:49 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080915 (trigger=324744). The BAT on-board calculated location 
is RA, Dec 18.004, -76.014 which is 
   RA(J2000) = 01h 12m 01s
   Dec(J2000) = -76d 00' 51"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 20 sec.  The peak count rate
was ~700 counts/sec (15-350 keV), at ~2 sec after the trigger. 

Due to an observing constraint, Swift will not slew until 
T0+62.4 minutes. There will be no XRT or UVOT data until
this time. 

Burst Advocate for this burst is S. R. Oates (sro AT mssl.ucl.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080915A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8228
SUBJECT: GRB 080915: ROTSE-III Optical Limits
DATE:    08/09/15 00:45:01 GMT
FROM:    Wiphu Rujopakarn at U AZ/Steward  <wiphu@as.arizona.edu>

W. Rujopakarn (Steward), H. Swan (U Mich), T. Guver (U Arizona) report on
behalf of the ROTSE collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia,
responded to GRB 080915 (Swift trigger 324744; Oates et al., GCN 8227),
producing images beginning 11.2 s after the GCN notice time. An automated
response took the first image at 00:03:42.2 UT, 52.2 s after the burst,
under cloudy conditions. These observations were affected by the full
moon. We took 10 5-sec, and 1 20-sec exposures. These unfiltered images
are calibrated relative to USNO A2.0 (R). Imaging is on going.

Comparison to the DSS (second epoch) reveals no new sources within the
3-sigma Swift/BAT error circle. Individual images have limiting magnitudes
ranging from 14.0-14.3; we set the following specific limit.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
00:03:42.2   00:03:47.2         5     14.2           52.2       N


GRB_name: GRB080915A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8230
SUBJECT: GRB 080915, Swift-BAT refined analysis
DATE:    08/09/15 12:32:14 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
S. R. Oates (UCL-MSSL), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080915 (trigger #324744)
(Oates, et al., GCN Circ. 8227).  The BAT ground-calculated position is
RA, Dec = 17.911, -76.042 deg, which is 
   RA(J2000)  =  01h 11m 38.5s 
   Dec(J2000) = -76d 02' 29.9" 
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 89%.
 
The mask-weighted light curve shows a single FRED-like peak starting
at ~T-5 sec, peaking at ~T+4 sec and ending at ~T+25 sec.
T90 (15-350 keV) is 14 +- 5 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.2 to T+16.2 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.64 +- 0.29.  The fluence in the 15-150 keV band is 2.3 +- 0.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+3.03 sec in the 15-150 keV band
is 0.5 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/324744/BA/


GRB_name: GRB080915A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8231
SUBJECT: GRB 080915: Swift-XRT afterglow detection and analysis
DATE:    08/09/15 12:34:11 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans (U. Leicester) and S.R. Oates (MSSL/UCL)
report on behalf of the Swift-XRT team.

We have analysed 1.7 ks of XRT data on GRB080915 (Oates et al, GCN Circ
8227), beginning  4.9 ks after the GRB trigger. Swift did not slew
immediately to the burst due to an Earth limb constraint.

We find a faint, fading source with a mean count rate ~0.01 counts per
second at a position of RA, Dec=17.9473, -76.0204 degrees, which is
equivalent to:

RA (J2000):  01h 11m 47.35s
Dec (J2000): -76d 01' 13.4"

with an uncertainy of 6.5 arcsec (radius, 90% containment). This
position is 54 arcsec from the BAT position, within the BAT error
circle.

The light curve shows a power-law decay with an index of 0.94
(+1.19/-0.58); the large uncertainty arises because the light curve
contains only 2 points.

A spectrum formed from the PC data can be modelled with an absorbed
power-law. The absorption column is poorly constained, but consistent
with the Galactic value of 6.7 x 10^20 cm^-2 (Kalberla et al. 2005), and
the photon index is 2.3 (+2.6, -1.3).

If the light curve continues to decay at alpha=0.94 we predict a count
rate at T0+24 hrs of 0.0018  counts per second. This corresponds to an
observed (unabsorbed) 0.3-10 keV flux of 6.36 x 10^-14 (1.22 x 10^-13)
erg cm^-2 s^-1.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB080915A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8232
SUBJECT: GRB 080915: Swift/UVOT Upper Limits
DATE:    08/09/15 13:39:55 GMT
FROM:    Alice Breeveld at MSSL-UCL  <aad@mssl.ucl.ac.uk>

A. Breeveld (MSSL-UCL) and S.R. Oates (MSSL-UCL) report on behalf of the
Swift/UVOT team:

The Swift/UVOT observed the field of GRB 080915 (Oates et al., GCN Circ.
8227) with settled exposures starting 3872s after the trigger. We do not
find a source in any of the UVOT observations inside the XRT error
circle (Evans et al., GCN Circ. 8231). The 3-sigma upper limits in the
UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for
detecting a source in the first white finding chart exposure and
subsequent co-added exposures are:

Filter          T_start T_stop  Exp     Mag (3-sigma UL)
                  (s)     (s)     (s)
=========================================================
white (FC)      3872    3972    98.2    > 19.9
white           5004    5204    196.6   > 20.5
v               3979    4179    196.6   > 18.8
v               9633    10539   885.1   > 19.7
b               4799    4999    196.6   > 19.6
u               4594    4794    196.6 > 19.1
uvw1            4389    4589    196.6 > 19.3
uvm2            4184    11087   731.3   > 20.4
uvw2            5210    5329    117.3 > 19.6

The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E(B-V) = 0.049 mag in the
direction of the burst (Schlegel et al. 1998).


GRB_name: GRB080915A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8233
SUBJECT: GRB 080915: REM NIR early observations
DATE:    08/09/15 15:28:59 GMT
FROM:    Stefano Covino at Brera Astronomical Observatory  <stefano.covino@brera.inaf.it>

S. Covino, P. D'Avanzo, L.A. Antonelli, D. Malesani, D. Fugazza, L.  
Calzoletti,  S. Campana, G.  Chincarini, M.L. Conciatore, S. Cutini,  
V. D'Elia,  F. D'Alessio, F.  Fiore, P. Goldoni, D. Guetta,  C.  
Guidorzi, G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E.  
Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L.  Stella,  
G.  Stratta, G. Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F.  
Vitali report on behalf of the REM team:


The robotic 60-cm REM telescope located at La Silla (Chile) observed  
automatically the field of the GRB 080915 (Oates et al. GCN 8227) on  
Sep 15 starting from about 2 min after the GRB time for 30 min. In  
the XRT error circle (Evans et al. GCN 8231) we see no sources  
fainter than the 2MASS limits in the J, H and K bands.


GRB_name: GRB080915B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8234
SUBJECT: GRB 080915B: Swift detection of a burst
DATE:    08/09/15 16:04:26 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

H. Ziaeepour (UCL-MSSL), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
C. Gronwall (PSU), S. T. Holland (CRESST/USRA/GSFC),
J. A. Kennea (PSU), J. Mao (INAF-OAB), P. T. O'Brien (U Leicester),
S. R. Oates (UCL-MSSL), J. P. Osborne (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL), A. M. Parsons (GSFC),
D. Perez (U Leicester), M. Perri (ASDC), T. Sakamoto (NASA/UMBC),
R. L. C. Starling (U Leicester), G. Stratta (ASDC) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 15:53:35 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080915B (trigger=324805). The BAT on-board calculated 
location is RA, Dec 213.078, -11.473 which is 
   RA(J2000) = 14h 12m 19s
   Dec(J2000) = -11d 28' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single FRED peak
structure with a duration of about 5 sec.  The peak count rate
was ~13,000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to the Solar observing constraint, Swift cannot slew to the 
BAT position until mid-December. There will thus be no XRT or 
UVOT data for this trigger. 

Burst Advocate for this burst is H. Ziaeepour (hz AT mssl.ucl.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080912A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8235
SUBJECT: GRB 080912 : Fermi GBM detection
DATE:    08/09/15 16:57:29 GMT
FROM:    Sheila McBreen at MPE  <smcbreen@mpe.mpg.de>

S. McBreen, E. Bissaldi and A. von Kienlin (MPE) report on
behalf of the Fermi GBM Team:

"At 08:38:55 UT on 12 September 2008, the Fermi Gamma-ray Burst Monitor
triggered and located GRB 080912 (trigger 242901536 / 080912360).
The on-ground calculated location, using the Fermi GBM
trigger data, is RA = 26.1, Dec = -5.1 (J2000 degrees)
(equivalent to J2000 01h 44m, -05d 06'),
with a statistical uncertainty of 8.4 degrees (radius, 1-sigma
containment; there is additionally a systematic error which is
currently estimated to be 2 to 3 degrees). The angle from the
Fermi LAT boresight is 56 degrees.

This GRB consists of one main pulse starting at T0-3 with a
T90 (50-300 keV) of about 17 s. The  time-averaged
spectrum in this interval is adequately fit  by a
powerlaw function with index -1.74 +/-0.07.

The fluence (25-1000 keV) is 3.3 (+/-0.1)E-06 erg/cm2.
The peak flux (25-1000 keV) on the 64 ms timescale
is 4.1 +/- 0.7 ph/s/cm2.

The spectral analysis results presented above are preliminary;
the final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB080915B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8236
SUBJECT: GRB 080915B, Swift-BAT refined analysis
DATE:    08/09/15 19:49:30 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

K. McLean (GSFC/UMD), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU),
H. Ziaeepour (UCL-MSSL)
(i.e. the Swift-BAT team):
 
Using the data set from T-28 to T+930 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080915B (trigger #324805)
(Ziaeepour, et al., GCN Circ. 8234).  The BAT ground-calculated position is
RA, Dec = 213.088, -11.491 deg, which is 
   RA(J2000)  =  14h 12m 21.2s 
   Dec(J2000) = -11d 29' 26.9" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 74%.
 
The mask-weighted light curve shows a roughly symmetric peak starting
at ~T-0.5 sec, peaking at ~T+0.6 sec, and ending at ~T+4.5 sec.
T90 (15-350 keV) is 3.9 +- 0.7 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.5 to T+6.1 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.48 +- 0.35, 
and Epeak of 42.3 +- 9.1 keV (chi squared 54.5 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 9.9 +- 0.6 x 10^-7 erg/cm2
and the 1-sec peak flux measured from T+0.18 sec in the 15-150 keV band is
8.5 +- 0.3 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.02 +- 0.08 (chi squared 62.6 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/324805/BA/


GRB_name: GRB080916A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8237
SUBJECT: GRB 080916: Swift detection of a burst with optical afterglow
DATE:    08/09/16 10:03:53 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

H. Ziaeepour (UCL-MSSL), L. Vetere (PSU),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
S. Campana (INAF-OAB), P. A. Evans (U Leicester), C. Gronwall (PSU),
H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (MSSL),
V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB), S. R. Oates (UCL-MSSL),
K. L. Page (U Leicester), D. M. Palmer (LANL), B. Preger (ASDC),
P. Romano (INAF-IASFPA), T. Sakamoto (NASA/UMBC),
M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 09:45:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080916 (trigger=324895).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 336.302, -57.022 which is 
   RA(J2000) = 22h 25m 12s
   Dec(J2000) = -57d 01' 17"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure with a duration of about 60 sec.  The peak count rate
was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 09:46:30.8 UT, 70.2 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 336.27802, -57.02190 which is
equivalent to:
   RA(J2000)  = 22h 25m 6.72s
   Dec(J2000) = -57d 01' 18.8"
with an uncertainty of 3.3 arcseconds (radius, 90% containment). This
location is 46 arcseconds from the BAT onboard position, within the BAT
error circle. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.83e+20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)
filter starting 76 seconds after the BAT trigger. There is a candidate
afterglow in the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 22:25:06.19 = 336.2758
  DEC(J2000) = -57:01:22.8  = -57.0230
with a 1-sigma error radius of about 0.5 arc sec. This position is 5.9 arc
sec. from the center of the XRT error circle. The estimated magnitude is 18.3
with a 1-sigma error of about 0.5 mag. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.02. 

Burst Advocate for this burst is H. Ziaeepour (hz AT mssl.ucl.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080916A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8238
SUBJECT: GRB 080916: REM candidate afterglow
DATE:    08/09/16 10:04:09 GMT
FROM:    Stefano Covino at Brera Astronomical Observatory  <stefano.covino@brera.inaf.it>

D. Fugazza, S. Covino, P. D'Avanzo, L.A. Antonelli,
L. Calzoletti,  S. Campana, G.  Chincarini, M.L. Conciatore, S. Cutini,   
V. D'Elia,  F. D'Alessio, F.  Fiore, P. Goldoni, D. Guetta,  C.  
Guidorzi, G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E.   
Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L.  Stella,   
G.  Stratta, G. Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F.   
Vitali report on behalf of the REM team:


The robotic 60-cm REM telescope located at La Silla (Chile) observed  
automatically the field of the GRB 080916 on
Sep 16 starting from about 20 s after the GRB time. We see a source  
not present in the 2MASS catalogue with approximately H~14.5 one  
minute after the burst at the coordinates RA=22:25:06.19,  
DEC=-57:01:24.1 (error 1 arcsec).

Further observations are in progress.

[GCN OPS NOTE(16sep08):  The author requests that people should use
the 8238 Circular as the primary source.  The 8239 Circular was
the result of multiple efforts of a distributed team.]
[GCN OPS NOTE(16sep08): Per author's request, DM was removed
from the author list.]


GRB_name: GRB080916A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8239
SUBJECT: GRB 080916: REM detection of the NIR afterglow
DATE:    08/09/16 11:45:46 GMT
FROM:    Angelo Antonelli at Obs. Astro. di Roma  <a.antonelli@oa-roma.inaf.it>

L.A. Antonelli, S. Covino, P. D'Avanzo, D. Fugazza, L.  
Calzoletti,  S. Campana, G.  Chincarini, M.L. Conciatore, S. Cutini,  
V. D'Elia,  F. D'Alessio, F.  Fiore, P. Goldoni, D. Guetta,  C.  
Guidorzi, G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E.  
Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L.  Stella,  
G.  Stratta, G. Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F.  
Vitali report on behalf of the REM team:


The robotic 60-cm REM telescope located at La Silla (Chile) observed  
automatically the field of the GRB 080916 (Ziaeepour et al. GCN 8237)  
on Sep 16 starting observations about 19.4 sec after the GRB. We  
clearly detect a NIR source at RA(J2000)=22:25:06.13, Dec.(J2000) 
=-57:01:22 with an uncertainty of 1" which is compatible with the  
position of the UVOT source (Ziaeepour et al. GCN 8237). At the  
beginning of the observation the source had a magnitude H=14.0+/-0.3,  
calibrated against 2MASS. The source showed a clear fading behavior  
during the REM observation.

[GCN OPS NOTE(16sep08):  The author requests that people should use
the 8238 Circular as the primary source.  The 8239 Circular was
the result of multiple efforts of a distributed team.]
[GCN OPS NOTE(16sep08): Per author's request, DM was removed
from the author list.]


GRB_name: GRB080916B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8240
SUBJECT: GRB 080916B: Swift detection of a burst
DATE:    08/09/16 14:55:24 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

G. Stratta (ASDC), S. D. Barthelmy (GSFC),
A. P. Beardmore (U Leicester), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
S. D. Hunsberger (PSU), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), J. Mao (INAF-OAB),
C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC),
P. T. O'Brien (U Leicester), S. R. Oates (UCL-MSSL),
J. P. Osborne (U Leicester), K. L. Page (U Leicester),
M. Perri (ASDC), B. Preger (ASDC), R. L. C. Starling (U Leicester),
M. C. Stroh (PSU) and T. N. Ukwatta (GSFC/GWU) report on behalf of
the Swift Team:

At 14:44:47 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080916B (trigger=324907).  The BAT on-board calculated location is 
RA, Dec 163.624, +69.044 which is 
   RA(J2000) = 10h 54m 30s
   Dec(J2000) = +69d 02' 39"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 50 sec.  The peak count rate
was ~750 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to an observing constraint, Swift will not slew until 
T0+18.9 minutes. There will be no XRT or UVOT data until
this time. 

Burst Advocate for this burst is G. Stratta (giulia.stratta AT asdc.asi.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080916A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8241
SUBJECT: GRB 080916A: Enhanced Swift-XRT position
DATE:    08/09/16 15:21:27 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2559 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 080916A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 336.27682, -57.02271 which is equivalent
to:

RA (J2000): 22h 25m 6.44s
Dec (J2000): -57d 01' 21.7"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB080916B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8242
SUBJECT: GRB 080916B: Swift-XRT afterglow detection
DATE:    08/09/16 15:36:21 GMT
FROM:    Matteo Perri at ISAC/ASDC  <perri@asdc.asi.it>

G. Stratta, M. Perri, P. Evans report on behalf of
the Swift-XRT Team:

The XRT began observing the field at 15:07:22.2 UT, 1354.9 seconds
after the BAT trigger. Using promptly downlinked data we find an
uncatalogued X-ray source located at RA, Dec 163.66560, 69.06574 which
is equivalent to:
   RA(J2000)  = 10h 54m 39.74s
   Dec(J2000) = +69d 03' 56.7"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 94 arcseconds from the BAT onboard position, within the BAT
error circle.

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.8e+20 cm^-2 (Kalberla et al. 2005).


GRB_name: GRB080916A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8243
SUBJECT: GRB 080916A, Swift-BAT refined analysis
DATE:    08/09/16 17:06:23 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

W. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL),
A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU),
H. Ziaeepour (UCL-MSSL)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080916A (trigger #324895)
(Ziaeepour, et al., GCN Circ. 8237).  The BAT ground-calculated position is
RA, Dec = 336.289, -57.026 deg, which is 
   RA(J2000)  =  22h 25m 09.3s 
   Dec(J2000) = -57d 01' 33.7" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 82%.
 
The mask-weighted light curve shows two overlapping FRED peaks
starting at ~T-3 sec and ending at ~T+100 sec.
T90 (15-350 keV) is 60 +- 7 sec (estimated error including systematics).
 
The time-averaged spectrum from T-2.4 to T+88.6 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.17 +- 0.21, 
and Epeak of 94.6 +- 23.0 keV (chi squared 48.0 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 4.0 +- 0.1 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+1.25 sec in the 15-150 keV band is
2.7 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.63 +- 0.05 (chi squared 64.5 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/324895/BA/


GRB_name: GRB080916A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8244
SUBJECT: GRB 080916A: Swift XRT refined analysis
DATE:    08/09/16 17:19:57 GMT
FROM:    Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>

R.L.C. Starling (U. Leicester) and H. Ziaeepour (MSSL-UCL) report on 
behalf of the Swift-XRT team:

We have analysed the first two orbits of Swift XRT data for GRB 080916A 
(Ziaeepour et al., GCN Circ. 8237) from T0+70 s to T0+7440 s with total 
exposure time 3.4 ks. The enhanced X-ray position is given in Evans et 
al., GCN Circ. 8241. 

The light curve can be represented by a 5-segment broken power law with an 
initial decay alpha1=1.3+0.4/-0.6 breaking at Tbk1=102+4/-6 s to a steep 
decay of alpha2=3.5+/-0.3 until Tbk2=190+25/-13 s. The light curve then 
flattens to alpha3=1.07+0.06/-0.3 and breaks at Tbk3=690+150/-140 s to a 
further steep decay of alpha4=2.9+2/-0.8. From Tbk4=1270+240/-220 s the 
decay becomes shallow again with alpha5=0.3+/-0.2. 

The spectrum from 3.2 ks of Photon Counting mode data can be fit with an 
absorbed power law with photon index Gamma=2.1+/-0.2 and intrinsic 
absorption (in excess of the Galactic value of 1.8e20 cm-2) of 
nH=(2.6+0.7/-0.6)e21 cm-2. This is consistent with the spectrum formed 
from the initial 170 s of Windowed Timing mode data. The observed 
(unabsorbed) count rate to flux conversion is 1 count/s = 4.0e-11 
(6.8e-11) erg/cm2/s. 

The predicted count rate at T+24hr would be approximately 0.1 count/s if 
the decay continues on the current plateau-like phase.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB080916C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8245
SUBJECT: GRB 080916C: Fermi GBM Detection
DATE:    08/09/16 18:09:46 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

Adam Goldstein (UAH) and Alexander van der Horst (NASA/MSFC) report on
behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 00:12:45 UT on 16 September 2008, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered and located the bright GRB 080916C (trigger 243216766 /
080916.009). The on-ground calculated location, using the GBM trigger data,
is RA = 121.8,  Dec = -61.3 (J2000 degrees, equivalent to J2000 8h 07m,
-61d 18'), with a statistical uncertainty of less than 1 degree (radius,
1-sigma
containment) and an additional systematic error which is currently estimated
to be 2 to 3 degrees. The angle from the Fermi Large Area Telescope (LAT)
boresight is 52 degrees.

This GRB has several peaks, with T90 (50-300 keV) = 66 s and
T50 (50-300 keV) = 33 s. This burst is detected up to several MeV;
spectral analysis is ongoing."


GRB_name: GRB080916C
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8246
SUBJECT: GRB 080916C: Fermi LAT observation
DATE:    08/09/16 18:25:23 GMT
FROM:    Nicola Omodei at INFN(Pisa)/GLAST  <nicola.omodei@pi.infn.it>

H. Tajima (SLAC), J. Bregeon (INFN Pisa), J. Chiang (SLAC), G. Thayer (SLAC)
on behalf of the Fermi LAT team:

We report a detection by the Fermi Large Area Telescope (LAT) of 
emission from the long GRB 080916C, which was triggered by the Fermi 
Gamma-ray Burst Monitor (GBM) at 00:12:45 UT on September 16th 2008 (GCN 
8245). The angle of the GBM best position (RA, Dec=121.8,-61.3) with 
respect to the LAT boresight was 52 degrees at the time of the trigger, 
which is close the edge of our field of view.

The data from the Fermi LAT shows a significant increase in the event 
rate within 10 degrees of the GBM location after the GBM trigger that is 
spatially and temporally correlated with the GBM emission with high 
significance. More than 10 photons are observed above 1 GeV during this 
time.

The best LAT on-ground localization is found to be (RA,Dec=119.88, 
-56.59) with a 90% containment radius of 0.13 deg (statistical; 68% 
containment radius: 0.09 deg, preliminary systematic error is less than 
0.1 deg) which is consistent with the GBM localization.

This circular is an official product of the Fermi LAT team.


GRB_name: GRB080916B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8247
SUBJECT: GRB 080916B: Enhanced Swift-XRT position
DATE:    08/09/16 19:40:44 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1049 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 080916B, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 163.66512, +69.06545 which is equivalent
to:

RA (J2000): 10h 54m 39.63s
Dec (J2000): +69d 03' 55.6"

with an uncertainty of 5.1 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB080915A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8248
SUBJECT: GRB 080915a, SMARTS optical/IR observations 
DATE:    08/09/16 19:57:08 GMT
FROM:    Bethany Cobb at Yale U  <cobb@astro.yale.edu>

B. E. Cobb (UC Berkeley), reports:

Using the ANDICAM instrument on the SMARTS 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 080915a
(GCN 8227, Oates et al.) with a mid-exposure time of
2008-09-15 01:54 UT (~1.9 hrs post-burst).  We then re-observed
the field at 2008-09-16 6:12 UT (~30.2 hrs post-burst).  Total summed 
exposure times for each observation amounted to 36 minutes in I
and 30 minutes in J.

A comparison of our two epochs of imaging reveals no variable source
at the position of the X-ray afterglow reported by Evans et al. (GCN 
8231).  Our limiting magnitudes are I>21.9 and J>20.1.
(Optical photometry is calibrated against Landolt standard stars
and IR photometry is calibrated against 2MASS stars in the field.)


GRB_name: GRB080916A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8249
SUBJECT: GRB080916A: Refined Swift/UVOT Observations
DATE:    08/09/16 19:58:10 GMT
FROM:    Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>

S. R. Oates (UCL-MSSL) and H. Ziaeepour (UCL-MSSL) report on
behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 080916A, 78s after the BAT trigger (Ziaeepour et al., GCN 8237).
We detect the afterglow in all of the UVOT filters at the position:

RA(J2000)  =  22:25:06.20
DEC(J2000) =  -57:01:22.9

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence).
This position is consistent with the UVOT enhanced XRT position (Evans et
al., GCN 8241) and the REM position (Fugazza et al., GCN 8238).

UVOT magnitudes are reported below for the finding charts (fc) and images:

Filter    Tstart(s)  Tstop   Expo(s)   Magnitude/3sigUL
-----------------------------------------------------
white (fc)    78    178        98       18.33 +/- 0.06
white        872    972        98       18.47 +/- 0.06
v     (fc)   182    582       393       17.55 +/- 0.06
v            978   1378       393       18.39 +/- 0.11
b           1458   1477        19       18.90 +/- 0.35
u            538    658        19       17.53 +/- 0.19
w1           613    633        19       18.25 +/- 0.39
m2           741   1565        39       18.42 +/- 0.40
w2           692    864        39       18.75 +/- 0.37
-----------------------------------------------------

These magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E{B-V} = 0.02 mag (Schlegel et al.
1998). The photometry is on the UVOT flight system described in Poole
et al. (2008,MNRAS,383,627).


GRB_name: GRB080916B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8250
SUBJECT: GRB 080916B, Swift-BAT refined analysis
DATE:    08/09/16 20:55:15 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), G. Stratta (ASDC),
J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team) report:
 
Using the data set from T-239 to T+617 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080916B (trigger #324907)
(Strata, et al., GCN Circ. 8240).  The BAT ground-calculated position is
RA, Dec = 163.632, 69.061 deg, which is 
   RA(J2000)  =  10h 54m 31.6s 
   Dec(J2000) = +69d 03' 38.2" 
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 53%.
 
The mask-weighted light curve shows a weak FRED-like peak starting
at ~T-4 sec, peaking at ~T+3 sec, and ending at ~T+50 sec.  There is a
possibility of very weak emission lasting out to at least T+350 sec,
at which time the spacecraft slewed away fro the burst location.
T90 (15-350 keV) is 32 +- 8 sec (estimated error including systematics).
 
The time-averaged spectrum from T-3.3 to T+35.7 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.49 +- 0.23.  The fluence in the 15-150 keV band is 6.3 +- 0.9 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+3.30 sec in the 15-150 keV band
is 0.6 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/324907/BA/


GRB_name: GRB080916C
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8251
SUBJECT: IPN Triangulation and Energy Spectrum of GRB080916C
DATE:    08/09/16 22:36:31 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@ssl.berkeley.edu>

K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team, 

S. Golenetskii, R.  Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and
T. Cline on behalf of the Konus-Wind team

E. Bellm, D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger, W.
Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team, 

A. von Kienlin, G. Lichti, and A. Rau, on behalf of the
INTEGRAL SPI-ACS GRB team, and

E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, I. Lapshov,
F. Lazzarotto, L. Pacciani, M. Galli, and M. Marisaldi, on behalf 
of the AGILE Team, 

report:

GRB080916C (Goldstein and van der Horst, GCN 8245; Tajima et
al., GCN 8246) was also observed by AGILE (MCAL, SuperAGILE, and ACS -
but not localized), RHESSI, INTEGRAL (SPI-ACS), Konus-Wind,
and MESSENGER.  A preliminary triangulation gives a long,
narrow error box centered at RA, Dec = 119.830, -56.790 degrees
(0.2 degrees from the center of the LAT error circle), whose
corners are:

 RA(2000)    DEC(2000)             
  119.486    -62.130
  120.126    -62.702
  119.901    -50.632
  120.321    -51.274

A figure is posted at ssl.berkeley.edu/ipn3/080916C.

Using the RHESSI data between 100 keV and 17 MeV, the time-integrated
spectrum for the 62-second interval beginning at 00:12:46 UT can be described
by a cutoff power law with alpha ~ -1.2 +/- 0.3, Epeak ~ 1100 +/- 500 keV,
and fluence ~ (9.0 +/- 1.6) x 10^-5 ergs/cm^2 (100 keV - 10 MeV).


Both the triangulation and the energy spectrum can be substantially
improved.


GRB_name: GRB080916B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8252
SUBJECT: GRB 080916B: Swift UVOT Refined Analysis
DATE:    08/09/17 00:42:53 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU) and G. Stratta (ASDC) report on behalf of the
Swift UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 080916B, 1359s after the BAT trigger (Stratta et al., GCN 8240).
There is a possible detection of an afterglow in the UVOT white filter
at:

     RA (J2000)  10:54:39.78
    Dec (J2000)  69: 3:57.9

with an estimated uncertainty of 0.8 arcsec (radius, 90% confidence).
This position is consistent with the UVOT enhanced XRT position (Evans
et al., GCN 8247).  The afterglow candidate does not appear in the DSS
images, and photometry from the second orbit of Swift observations
suggests that it has faded.

UVOT magnitudes and 3-sigma upper limits are reported in the following
table:

Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-----------------------------------------------------
white    1359.0    1458.8    98.2   20.50 +/- 0.21
white    7826.0    8025.7   196.6     > 21.27
v        1340.9    2920.7   342.1     > 19.62
b        1516.3    2676.5   155.6     > 20.32
u        1491.6    2651.7   155.6     > 19.91
uvw1     1467.3    2627.3   155.5     > 19.91
uvm2     1604.9    3076.8   285.0     > 20.06
uvw2     1556.0    2716.0   155.5     > 19.91

The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_{B-V} = 0.02 mag.
All photometry is on the UVOT flight system described in Poole et al.
(2008, MNRAS, 383, 627).


GRB_name: GRB080916C
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8253
SUBJECT: GRB 080916C: Swift/XRT detection of possible afterglow
DATE:    08/09/17 04:41:53 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

Jamie A. Kennea reports on behalf of the Swift Team:

At 17:08 UT, September 16th 2008 Swift began TOO observations of the Fermi 
GBM and LAT detected GRB 080916C (GCN 8245,8246). Preliminary analysis of 
downlinked data from this observation reveals a single point source 
detected in the field of view at RA, Dec = 119.8459, -56.63891 which is 
equivalent to:

RA (J2000): 07h 59m 23.0s
Dec (J2000): -56d 38' 20.1"

with an estimated uncertainty of 8 arcsec (radius, 90% confidence). We 
note that this point source is uncatalogued and 189 arcseconds from the 
center of the Fermi LAT error circle (GCN 8246), within the LAT 90% 
confidence error circle. Currently we cannot determine if this source is 
fading, and therefore cannot confirm if this source is associated with GRB 
080916C. Observations of this source are on-going.


GRB_name: GRB080916A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8254
SUBJECT: GRB080916A: Spectroscopic redshift
DATE:    08/09/17 07:35:16 GMT
FROM:    Johan U. Fynbo at U.Copenhagen  <jfynbo@astro.ku.dk>

J. P. U. Fynbo, D. Malesani, J. Hjorth, J. Sollerman, C. C. Thoene (DARK),
report on behalf of a larger collaboration.

We observed the field of GRB 080916A (Ziaeepour et al., GCN 8237) with the
ESO VLT equipped with FORS1. Observations started on 2008 Sep 17.097 UT,
17.1 hr after the burst, for a total exposure time of 1 hr with the 300V
grism. Based on MgII absorption and emission lines from [OII] and [OIII]
we infer a redshift for GRB080916A of z=0.689 (based a preliminary
wavelength calibration).

We acknowledge excellent support from the observing staff at
Paranal, in particular Dominique Naef, Heidi Korhonen and Chris Lidman.


GRB_name: GRB080916C
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8255
SUBJECT: GRB 080916C: Enhanced XRT position 
DATE:    08/09/17 09:01:33 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, J.P. Osborne, A.P. Beardmore and M.R. Goad, (U. Leicester)
report on behalf of the Swift-XRT team.

Using 1310 s of XRT Photon Counting mode data and 1 UVOT images, we find an 
astrometrically corrected X-ray position (using the XRT-UVOT alignment and 
matching to the USNO-B1 catalogue): RA, Dec = 119.84706, -56.63788 which is 
equivalent to:

RA (J2000): 07 59 23.29
Dec (J2000): -56 38 16.4

with an uncertainty of 2.1 arcsec (90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB080913A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8256
SUBJECT: GRB 080913: Konus-Wind and Swift/BAT joint spectral analysis
DATE:    08/09/17 09:41:53 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

V. Pal'shin, S. Golenetskii, R.Aptekar, E. Mazets, D. Frederiks, and
T. Cline on behalf of the Konus-Wind team,

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC),
W. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
D. Palmer (LANL), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), and T. Ukwatta (GWU)
on behalf of the Swift-BAT team,

report:

We performed the Konus-Wind and the Swift/BAT joint spectral analysis
of GRB 080913 (Swift/BAT trigger #324561: Schady et al., GCN Circ. 8217,
Stamatikos et al. GCN Circ. 8222).
Since the Konus-Wind observed this GRB in the waiting mode, we only
have 3 channel spectral data for the Konus-Wind which cover the energy
range from 20 keV to 1.3 MeV.  Therefore, the joint spectral analysis of
the Konus-Wind and the Swift/BAT data enables to derive the broad-band
spectral parameters of this burst.

The time interval of the spectral data for each instrument is chosen
from  T0(BAT)-4.1 to T0(BAT)+4.7 sec where T0(BAT) is the trigger time
of BAT at 06:46:54.1 UTC.  The energy ranges which we used in the joint
spectral analysis are 20-1300 keV and 14-150 keV for the Konus-Wind and
the Swift/BAT respectively.  The spectral data of two instruments are
fit with the spectral model multiplied by the constant factor to take
into account the systematic effective area uncertainties in the response
matrices of each instrument.

The spectrum is well fit with a power-law with exponential cutoff model:
dN/dE ~ E^{alpha}*exp(-(2+alpha)*E/Epeak). The constant factors of each
instrument agree within 5%.  No systematic residual from the best fit
model is seen in the spectral data of each instrument.  The best fit
spectral parameters are: alpha = -0.89(-0.46, +0.65) and Epeak = 131
(-48/+225) keV (chi2/dof = 43.7/58).  The best fit spectral parameters
for the Band function fixing beta=-2.5 are: alpha = -0.82(-0.53, +0.75)
and Epeak = 121 (-39/+232) keV (chi2/dof = 43.9/58).  The energy fluence
in the 15-1000 keV band calculated by a power-law with exponential
cutoff model for this 8.8 sec interval is 8.5(-2.2, +6.0)x10^-7 erg/cm2

All the quoted errors are at the 90% confidence level.

Assuming z = 6.7 (Fynbo et al., GCN Circ. 8225) and a standard cosmology
model with H_0 = 71 km/s/Mpc, Omega_M = 0.27, Omega_Lambda = 0.73, the
isotropic energy  release is E_iso ~7x10^52 erg in 1 keV to 10 MeV at
the GRB rest frame extrapolating the best Band function fit fixing
beta=-2.5.

Looking only at the parameters of the prompt emission, namely T90~1 sec
and Ep ~900 keV in the GRB rest frame, this burst could be classified as
a short burst.


GRB_name: GRB080916C
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8257
SUBJECT: GRB 080916C: GROND Detection of the Optical Afterglow Candidate
DATE:    08/09/17 10:55:42 GMT
FROM:    Christian Clemens at MPE  <cclemens@mpe.mpg.de>

C. Clemens (MPE), A. Rossi (Tautenburg Obs.), J. Greiner and S. McBreen (both 
MPE) report on behalf of the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI 
telescope at La Silla Observatory (Chile) observed the field of GRB 080916C, 
which triggered Fermi GBM (Goldstein et al., GCN #8245) and for which 
significant correlated emission was detected by the Fermi LAT (Tajima et al., 
GCN #8246). The field was followed up by Swift XRT (Kennea et al., GCN 
#8253).

Observations started at 07:57 UT on September 17th, 2008, 31.7 hr after the 
GBM trigger. They were performed at an average seeing of 1.5" and at an 
average airmass of 1.7 as well as under bright moon.

We found a faint source at the edge of the astrometrically corrected 2.1'' 
Swift-XRT error circle reported by Evans et al. (GCN #8255) at

RA (J2000) = 07h 59m 23.32s
DEC (J2000) = -56d 38' 18.0''

with an uncertainty of 0.5".

Based on the first 50 min of effective exposures, we estimate a preliminary 
magnitude of

z' ~ 21.74 mag +/- 0.17.

Given magnitude is calibrated against USNO-B1 field stars.

No statement about variability can be made at this point. Further observations 
are planned.

Please note, that no correction for the Galactic foreground reddening of 
E(B-V) = 0.32 mag (Schlegel et al., 1998) has been applied.


GRB_name: GRB080916C
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8258
SUBJECT: Konus-Wind observation of GRB 080916C
DATE:    08/09/17 11:30:55 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P.
Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind
team, report:

The long GRB 080916 (Fermi GBM trigger 243216766/080916.009; Goldstein 
and van der Horst, GCN 8245; Tajima et al., GCN 8246; Hurley et al., GCN 
8251) triggered Konus-Wind at T0=764.632 s UT (00:12:44.632).

The burst light curve shows the main part with a duration of ~70 s 
followed by a weak tail seen at least till ~T0+200 s.

As observed by Konus-Wind the burst
had a fluence of (1.24 +/- 0.17)x10^-4 erg/cm2,
and a 256-ms peak flux measured from T0+3.168 s
of (1.19 +/- 0.30)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+71.424 s) is well be fitted (in the 20 keV - 10 MeV 
range) by GRBM (Band) model for which:
the low-energy photon index is alpha = -1.040(-0.058, +0.065),
the high energy photon index beta = -2.26(-0.40, +0.21),
the peak energy Ep = 505(-70, +79) keV (chi2 = 75.6/84 dof).

All the quoted errors are at the 90% confidence level.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB080916_T00764/


GRB_name: GRB080916A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8259
SUBJECT: Konus-Wind observation of GRB 080916A
DATE:    08/09/17 14:31:01 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin,
D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov
and T. Cline, on behalf of the Konus-Wind team report:

The long GRB 080916A (Swift-BAT trigger # 324895:
Ziaeepour et al., GCN 8237, Baumgartner et al. 8243) triggered 
Konus-Wind at T0=35121.715 s UT (09:45:21.715).

The burst light curve shows a single pulse with a duration of ~40 s.

As observed by Konus-Wind the burst
had a fluence of 5.54(-0.66, +0.79)x10^-6 erg/cm2,
and a 256-ms peak flux measured from T0+1.024 s
of 1.05(-0.40, +0.41)x10^-6 erg/cm2/s
(both in the 20 keV - 1 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+33.024 s) is well fitted (in the 20 keV-1 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.00(-0.32, +0.38),
and Ep = 129(-21, +33) keV (chi2 = 32.0/51 dof).
Fitting by GRBM (Band) model yields only an upper limit on
the high energy photon index: beta < -2.43.

All the quoted errors are at the 90% confidence level.

Assuming z = 0.689 (Fynbo et al., GCN 8254) and a standard
cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, Omega_\Lambda =
0.73, the isotropic energy release E_iso ~7x10^51 erg, the peak 
luminosity (L_iso)_max ~ 2x10^51 erg/s, and Ep_rest ~220 keV.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB080916_T35121/


GRB_name: GRB080916B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8260
SUBJECT: GRB 080916B: Swift-XRT refined analysis
DATE:    08/09/17 15:17:17 GMT
FROM:    Matteo Perri at ISAC/ASDC  <perri@asdc.asi.it>

G. Stratta, M. Perri, B. Preger (ASDC) report on behalf of the
Swift-XRT team:

We have analyzed the first two orbits of Swift XRT data of
GRB 080916B (Stratta et al., GCN Circ. 8242), consisting of
2.8 ks of Photon Counting data collected starting
from 22.8 min after the burst.

During the XRT observation, from T0+1.4 ks to T0+8.5 ks,
the source shows a fading behaviour from 0.08 cts/s
to 0.02 cts/s. Assuming a power law model, the best fit decay index is
alpha = 1.0  0.2. At this rate we predict a count rate
level of 1.7 x 10-3 cts/s one day after the trigger.

The 0.3-10 keV extracted spectrum (2.8 ks of integration time)
is consistent with an absorbed power law model.
Fixing the column density to the Galactic value
(NH = 1.8 x 1020 cm-2 from Kalberla et al. 2007)
the best fit photon index is 2.0  0.5.

The observed 0.3-10.0 keV flux is (1.0+/-0.6) x 10-12 erg cm-2 s-1
which corresponds to an unabsorbed flux of 1.1 x 10-12  erg cm-2 s-1.
The count to observed flux conversion factor is 6.6 x 10-11 erg cm-2
count-1.

This Circular is an official product of the Swift-XRT team.


GRB_name: GRB080916C
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8261
SUBJECT: GRB 080916C: Swift XRT refined analysis
DATE:    08/09/17 15:24:55 GMT
FROM:    Matteo Perri at ISAC/ASDC  <perri@asdc.asi.it>

M. Perri, B. Preger, G. Stratta (ASDC) report on behalf of the
Swift XRT team:

The Swift XRT started observing the field of the FERMI GRB 080916C
(Goldstein et al., GCN Circ. 8245) at 2008-09-16 17:11:28 UT, about
17 hours after the trigger.

We confirm that the X-ray source reported by Kennea (GCN Circ. 8253) is
the afterglow of the GRB.

Using 2614 s of XRT Photon Counting mode data and 2 UVOT images, we find
an astrometrically corrected X-ray position (using the XRT-UVOT
alignment and matching to the USNO-B1 catalogue): RA, Dec = 119.84684,
-56.63801 which is equivalent to:

RA (J2000): 07 59 23.24
Dec (J2000): -56 38 16.8

with an uncertainty of 1.9 arcsec (90% confidence). This position is
consistent with the XRT position reported by Evans et al. (GCN Circ. 8255)
using less data.

The X-ray light curve from T+61 ks to T+102 ks can be fit with a single
power-law model with a decay index of 1.7 (-0.7) (+1.0).

A 7.6 ks exposure X-ray spectrum from T+61 ks to T+102 ks can be well
fit by an absorbed power-law model with a photon index of 2.1 (+0.9 -0.7)
and a column density of 3.7 (+3.3) (-2.1) x 10^21 cm^-2. We note that
the Galactic column density value in the direction of the burst is
1.5 x 10^21 cm^-2.
The observed 0.3-10.0 keV flux is 8.6 x 10-13 erg cm^-2 s^-1 which
corresponds to an unabsorbed flux of 1.5 x 10^-12  erg cm^-2 s^-1.

Providing the source continues to decay at the same rate, we predict an
observed flux of  about 3 x 10^-13 erg cm^-2 s^-1 at T+2 days.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB080916C
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8262
SUBJECT: GRB 080916C: Swift UVOT Refined Analysis
DATE:    08/09/17 17:59:31 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU), P. Schady (MSSL-UCL), and M. Perri (ASDC)
report on behalf of the Swift UVOT team:

The Swift/UVOT began observations of the field of GRB 080916C 17.0
hours after the Fermi GBM dectection (Goldstein & van der Horst, GCN
8245). No afterglow is detected within the XRT error circle (Evans, et
al., GCN 8255) in any of the observed UVOT filters.

UVOT magnitude 3-sigma upper limits are reported in the following
table:

Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
v         101253   101857     590        > 19.75
u          96469    97132     645        > 19.99
uvw1       66675    67517     829        > 20.34
uvw1       95562    96462     886        > 20.38
uvm2       61130    66667    1090        > 20.31
uvm2       94655    95555     886        > 20.20
uvw2      100347   101246     886        > 20.43

The quoted upper limits have not been corrected for the large expected
Galactic extinction along the line of sight of E_{B-V} = 0.32 mag
(Schlegel et al., 1998).  All photometry is on the UVOT flight system
described in Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB080916A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8263
SUBJECT: GRB 080916A: Fermi GBM detection
DATE:    08/09/17 22:39:42 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi (MPE), S. McBreen (MPE),
C.A. Wilson-Hodge (NASA/MSFC) and A. von Kienlin (MPE) 
report on behalf of the Fermi GBM Team: 


"At 09:45:18 UT on 16 September 2008, the Fermi Gamma-ray Burst Monitor
triggered and located GRB 080916A (trigger 243251119 / 080916406), which
was also detected by Swift (Ziaeepour et al., GCN 8237) and
Konus-Wind (Golenetskii et al., GCN 8259). The on-ground 
calculated location, using the Fermi GBM trigger data, is 
RA = 331.5, Dec = -58.1 (equivalent to J2000 
22h 06m, -58d 06'), with a statistical uncertainty of 3.2 degrees 
(radius, 1-sigma containment; there is additionally a systematic 
error which is currently estimated to be 2 to 3 degrees). 
This position is 2.8 deg from the Swift refined position
(Evans et al., GCN 8241). The angle from the Fermi LAT boresight 
to the Swift position is 76 degrees.

This long GRB consists of several peaks, with the brightest one
lasting from T0 to T0+13 s and a second peak from T0+13 s to T0+24 s
followed by weaker emission.
T90 (25-1000 keV) is about 60 sec, in agreement with 
the Swift-BAT refined analysis (Baumgartner et al., GCN 8243),
and T50 (25-1000 keV) is about 25 s.

The time-averaged spectrum from T0 to T0+58 sec is 
adequately fit by a power law function with an exponential
high energy cutoff.  The power law index is -0.9 +/-0.1 and
the cutoff energy, parameterized as Epeak, is 109 +/- 9 keV.

The fluence (25-1000 keV) is 1.5 (+/- 0.5)E-05 erg/cm2
and the peak flux (25-1000 keV) on the 1 s timescale
is 4.5 (+/- 0.7) ph/cm2/s.


The spectral analysis results presented above are preliminary; 
final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB080916A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8264
SUBJECT: GRB 080916A: Rapid PROMPT Observations
DATE:    08/09/17 22:57:02 GMT
FROM:    Rebecca Holmes at U.North Carolina  <rholmes@physics.unc.edu>

R. Holmes, M. Schubel, J. Haislip, D. Reichart, M. Nysewander, A. 
LaCluyze, K. Ivarsen, J. A. Crain, A. Foster, T. Brennan, and A. Trotter 
report:

Skynet observed the localization of GRB 080916A (Ziaeepour et al., GCN 
8237) with four of the 16" PROMPT telescopes at CTIO beginning 56 
seconds after the trigger in UBVRI.

We detect the afterglow (Fugazza et al., GCN 8238) in I.  At 56 seconds 
after the burst we measure I ~ 17.7 mag (calibrated to 5 USNO B1 stars).


GRB_name: GRB080916A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8266
SUBJECT: GRB 080916A: GROND lightcurve
DATE:    08/09/18 11:23:16 GMT
FROM:    Andrea Rossi at TLS Tautenburg  <rossi@tls-tautenburg.de>

A. Rossi (Tautenburg Obs.),T. Kruehler, J. Greiner, A. Yoldas, C. Clemens,
 R. Filgas (all MPE Garching), A. Kupcu Yoldas (ESO) and 
G. Szokoly (Eoetvoes Univ.,Budapest) report on behalf of the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405),  mounted at the 2.2m ESO/MPI
telescope at La Silla Observatory (Chile), started observations of the
field of GRB 080916A (Ziaeepour et al. GCN #8237) in g'r'i'z'JHK at 
23:57:34 UT on 2008-09-16, 14 hours after the burst trigger.

We clearly detect the optical afterglow detected by UVOT (Ziaeepour 
et al. GCN #8237) and REM telescope (Fugazza et al. GCN #8238). 
Observations continued for 60 min and were repeated at the mid-time 
06:40 UT for total 60 min.

Calibrating the field on USNO-B1 stars, we derive the following
r band magnitudes, not corrected for the Galactic foreground 
extinction corresponding to a reddening of E_(B-V)=0.019 mag 
(Schlegel et al. 1998):

midtime(s) r er
52239        21.8 0.03
54054        21.9 0.04
74076        22.1 0.07
76260         22.3 0.07

The total r band light curve is well fitted by power law with index 
of 0.81+- 0.13. Assuming the optical light curve continues 
the decline with the same power law index, we predict r' 
band magnitudes 23.4 at 3 days after the burst. 


GRB_name: GRB080913A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8267
SUBJECT: GRB080913: Swift-BAT spectral lag
DATE:    08/09/18 14:15:23 GMT
FROM:    Dong Xu at DARK,NBI  <dong@astro.ku.dk>

Dong Xu (DARK/NBI) reports

The Swift/BAT data were reduced in a standard way. Making use of the
Cross Correlation Function (CCF) for different energy bands over 15-150
keV, we found negligible spectral time lags, being consistent with the
values/range of previous Swift short-duration GRBs. Also we note the
rest-frame energy band which BAT corresponds to for this burst (z~6.7,
Fynbo et al. GCN 8225) is higher than that for previous GRBs.

DX is grateful to R. L. C. Starling, P. T. O'Brien, and K. Page through
the SPARTAN program on Swift data reduction.


GRB_name: GRB080915A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8268
SUBJECT: GRB 080915A: GROND upper limits
DATE:    08/09/18 15:09:18 GMT
FROM:    Thomas Kruehler at MPE/MPI  <kruehler@mpe.mpg.de>

A. Rossi (Tautenburg Obs.), T. Kruehler, J. Greiner, A. Yoldas,
C. Clemens, R. Filgas (all MPE Garching), A. Kupcu Yoldas (ESO)
and G. Szokoly (Eoetvoes Univ., Budapest), report on behalf of
the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405), mounted at the
2.2m ESO/MPI telescope at La Silla Observatory (Chile), started
observations of the field of GRB 080915A (Oates et al. GCN #8227)
in g'r'i'z'JHK at 00:07:25 UT on 2008-09-15, 4.6 minutes after the burst
and continued for 130 minutes.

The observations were resumed in the following night, starting at
05:18:45 UT and continued for 70 minutes.

We detect 2 sources, one inside the XRT error circle (Evans et al.GCN #8231)
at coordinates RA, DEC (J2000) = 01:11:47.83, -76:01:13.7,
the other at the edge of the XRT error circle at coordinates
RA, DEC (J2000) = 01:11:45.4, -76:01:10.5.

A comparison of the two observing runs does not reveal any evidence for
variability. We conclude that most likely none of them is associated with
GRB 080915A.

The co-added images from the first run then yield the following upper
limits measured at a mid-time of 0.038 days after the trigger and
calibrated on the SDSS standard star SA95-190:

g' > 23.8
r' > 23.7
i' > 23.5
z' > 23.1
J  > 20.5
H  > 19.3
K  > 18.3


GRB_name: GRB080919A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8270
SUBJECT: GRB 080919: Swift detection of a short burst
DATE:    08/09/19 00:41:17 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

B. Preger (ASDC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC),
S. T. Holland (CRESST/USRA/GSFC), S. D. Hunsberger (PSU),
S. Immler (CRESST/GSFC/UMD), H. A. Krimm (CRESST/GSFC/USRA),
C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), M. Perri (ASDC), T. Sakamoto (NASA/UMBC),
M. Stamatikos (NASA/ORAU), G. Stratta (ASDC), M. C. Stroh (PSU) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 00:05:13 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080919 (trigger=325268).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 265.289, -42.396 which is 
   RA(J2000)  =  17h 41m 09s
   Dec(J2000) = -42d 23' 45"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single spike
with a duration of about 1 sec.  The peak count rate
was ~3300 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 00:06:23.8 UT, 70.8 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 265.22379,
-42.36876 which is equivalent to:
   RA(J2000)  = 17h 40m 53.71s
   Dec(J2000) = -42d 22' 07.5"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 199 arcseconds from the BAT onboard position, outside the
BAT error circle. 

UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)
filter starting 82 seconds after the BAT trigger.  The 2.7'x2.7' sub-image 
covers 25% of the BAT error circle and none of the XRT error circle. 
The 8'x8' region for the list of sources generated on-board covers 90% of the 
BAT error circle and 100% of the XRT error circle. 
No afterglow candidate has been found in the initial data products. Typical
upper limit is ~18th magitude. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.49. We note that this is a crowded field. 

This event lies near to the direction of the Galactic Bulge
(long,lat = 348.03, -6.26) and so we cannot immediately rule out
the possibility that this source is Galactic.  However, the duration
and the spectral hardness of this event are consistent with a
classical Short GRB. 

Burst Advocate for this burst is B. Preger (preger AT asdc.asi.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080919A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8271
SUBJECT: GRB 080919: REM NIR observations
DATE:    08/09/19 05:06:36 GMT
FROM:    Stefano Covino at Brera Astronomical Observatory  <stefano.covino@gmail.com>

S. Covino, L.A. Antonelli, L. Calzoletti,  S. Campana, G. Chincarini,  
M.L. Conciatore, S. Cutini,  V. D'Elia,  F. D'Alessio, P. D'Avanzo,  
F. Fiore, D. Fugazza, P. Goldoni, D. Guetta, C. Guidorzi, G.L.  
Israel, E. Maiorano, N. Masetti, A. Melandri, E. Meurs, L. Nicastro,  
E. Palazzi, E. Pian, S. Piranomonte, L.  Stella,  G.  Stratta, G.  
Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F. Vitali report on  
behalf of the REM team:


The robotic 60-cm REM telescope located at La Silla (Chile) observed  
automatically the field of the short GRB 080919 (Preger et al. GCN  
8270) starting from about 74s s after the GRB time. For a technical  
problem the images are of mediocre quality. However, we detect a  
source consistent with the position of the XRT transient and already  
present in the 2MASS catalogue (RA=17:40:53.778, DEC=-42:22:07.36)  
with H = 13.73 +- 0.03. In our frames the source appears at about  
H~14.0, constant within the duration of the REM observations (about  
30min).

At the present stage, beyond the position consistency, we can not  
infer whether this source is related or not to the fading X-ray  
source reported in Preger et al. (GCN 8270). Further observations are  
then encouraged.


GRB_name: GRB080916C
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8272
SUBJECT: GRB 080916C: GROND Confirmation of the Optical Afterglow
DATE:    08/09/19 10:08:00 GMT
FROM:    Christian Clemens at MPE  <cclemens@mpe.mpg.de>

C. Clemens (MPE Garching), A. Rossi (Tautenburg Obs.), J. Greiner, S. McBreen, 
T. Kruehler, A. Yoldas (all MPE Garching), A. Kupcu Yoldas (ESO) and G. 
Szokoly (Eoetvoes Univ., Budapest) report on behalf of the GROND team:

We observed the field of GRB 080916C for a second time with GROND at 08:04 UT 
on September 19th, 2008, 3.3 d after the GBM trigger with 54 min of effective 
exposures. Observations were performed at an average seeing of 1.7" and at an 
average airmass of 1.7.

We do not detect the afterglow candidate first reported by Clemens et al. (GCN 
#8257) with the following 5-sigma upper limits:

z' > 22.7 mag.

These measurements strongly indicate a fading of the source compared to our 
first epoch observations. We therefore propose this is to be the afterglow of 
GRB 080916C.


GRB_name: GRB080916C
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8273
SUBJECT: GRB 080916C: GROND Confirmation of the Optical Afterglow
DATE:    08/09/19 10:08:07 GMT
FROM:    Christian Clemens at MPE  <cclemens@mpe.mpg.de>

C. Clemens (MPE Garching), A. Rossi (Tautenburg Obs.), J. Greiner, S. McBreen, 
T. Kruehler, A. Yoldas (all MPE Garching), A. Kupcu Yoldas (ESO) and G. 
Szokoly (Eoetvoes Univ., Budapest) report on behalf of the GROND team:

We observed the field of GRB 080916C for a second time with GROND at 08:04 UT 
on September 19th, 2008, 3.3 d after the GBM trigger with 54 min of effective 
exposures. Observations were performed at an average seeing of 1.7" and at an 
average airmass of 1.7.

We do not detect the afterglow candidate first reported by Clemens et al. (GCN 
#8257) with the following 5-sigma upper limits:

z' > 22.7 mag.

These measurements strongly indicate a fading of the source compared to our 
first epoch observations. We therefore propose this is to be the afterglow of 
GRB 080916C.


GRB_name: GRB080916C
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8274
SUBJECT: GRB 080916C: IRSF/SIRUS NIR Observation
DATE:    08/09/19 14:41:06 GMT
FROM:    Nobuyuki Kawai at Tokyo Tech  <nkawai@hp.phys.titech.ac.jp>

T. Nagayama (Kyoto University) reports on behalf of the IRSF/SIRIUS  
team:

We have imaged the field of GRB 080916C (van der Horst, GCN 8245)
based on the localization by Fermi/LAT (Tajima et al, GCN 8246) in J, H,
and Ks with the Simultaneous three-color InfraRed Imager for Unbiased
Survey (SIRIUS) on the Nagoya-SAAO 1.4m telescope (IRSF) starting at
2:53 on September 17 UT for 50 min.

The optical afterglow candidate suggested by Clemens et al. (GCN 8257,
GCN 8272) was detected marginally in H and Ks bands.
The preliminary magnitude was Ks= 18.6 +- 0.5.


GRB_name: GRB080919A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8275
SUBJECT: GRB 080919, Swift-BAT refined analysis
DATE:    08/09/19 15:06:18 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

W.H. Baumgartner (GSFC/UMBC),  S. D. Barthelmy (GSFC),
J.R. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H.A. Krimm (GSFC/USRA), C.B. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
D.M. Palmer (LANL), A.M. Parsons (GSFC), B. Preger (ASDC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T.N. Ukwatta (GWU) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080919 (trigger #325268)
(Preger, et al., GCN Circ. 8270).  The BAT ground-calculated position is
RA, Dec = 265.221, -42.375 deg which is
 RA(J2000)  =  17h 40m 53.0s
 Dec(J2000) = -42d 22' 29.5"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.

The mask-weighted light curve shows a broad peak of approximately 750 msec
duration starting at T+0 followed immediately by a weaker ~400 msec
peak seen mostly below 50 keV. T90 (15-350 keV) is 0.6 +- 0.1 sec 
(estimated error including systematics).

The time-averaged spectrum from T+0.1 to T+0.8 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum
is 1.10 +- 0.26.  The fluence in the 15-150 keV band is 7.2 +- 1.1 x 10-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.08 sec in the 15-150 keV band
is 1.2 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% 
confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/325268/BA/


GRB_name: GRB080919A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8276
SUBJECT: GRB 080919: Swift-XRT refined analysis
DATE:    08/09/19 16:40:58 GMT
FROM:    Matteo Perri at ISAC/ASDC  <perri@asdc.asi.it>

B. Preger (ASDC), G. Stratta (ASDC), M. Perri (ASDC) report on behalf
of the Swift XRT team:

The Swift XRT started observing the field of GRB080919 (trigger=325268;
Preger et al., GCN Circ. 8270) at 00:06:23.8 UT, 70.8 seconds
after the trigger.

The position of the X-ray afterglow is: RA, Dec= 265.223958, -42.368667
which is equivalent to:

RA (J2000): 17 40 53.75
Dec (J2000): -42 22 07.2

with an uncertainty of 2.0 arcsec (90% confidence).

The X-ray light curve from T0+74 s to T0+25 ks shows a fading behavior.
At ~T0 + 200 data show a 200 s long flare peaking
at ~T0 + 240 s with peak count rate of (1.2+/-0.3) cts/s
that is about a factor of 4 above the underlying continuum.
Excluding the flare, the light curve can be well modelled with
a broken power law, with best fit first decay index
alpha_1 = 2.2+/-0.2, a temporal break at ~T0 + 891 s and second
decay index alpha_2= 0.8+/-0.2.

A 4.5 ks exposure X-ray spectrum from T0+100 s to T0+7811 s can be
fit by an absorbed power-law model with a photon index of 2.0 (+0.5 -0.4)
and a column density of 3.9 (+3.2) (-2.3) x 10^21 cm^-2 in addition to
the Galactic column density value in the direction of the burst
(2.6 x 10^21 cm^-2, Kalberla et al. 2005).

Providing the source continues to decay at the same rate, we predict an
observed flux of about 2 x 10^-14 erg cm^-2 s^-1 at T0+1 days.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB080919A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8277
SUBJECT: GRB 080919: Swift/UVOT Refined Analysis
DATE:    08/09/19 18:17:38 GMT
FROM:    Stefan Immler at NASA/GSFC  <stefan.m.immler@nasa.gov>

S. Immler (CRESST/GSFC/UMD) and S. T. Holland (CRESST/USRA/GSFC), on 
behalf of the Swift Team:

Swift UVOT started observing GRB 080919 (Preger et al. GCN 8270) 82 
seconds after the BAT trigger. The source detected by REM (Covino et al. 
GCN 8271) is detected in all optical and in the uvw1 filter and shows no 
signs of fading over a period of ~25 ks after the trigger. It is the 
only optical source detected within the XRT error circle (Preger et al. 
GCN 8276). The following UVOT magnitudes (and 3-sigma upper limits) are 
measured:

Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-----------------------------------------------------
white      82    18561   2,203   18.40.1
v         188    23441   2,766   17.20.1
b         670    17648   1,375   18.30.1
u         645     7509    510   19.60.3
uvw1      620    25158   1,301   20.40.5
uvm2      594    24347   1,278    >20.4
uvw2      701    19375   1,809    >20.8

The quoted upper limits have not been corrected for the expected 
Galactic extinction along the line of sight of E(B-V) of 0.49 mag 
(Schlegel et al. 1998). All photometry is on the UVOT flight system 
described in Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB080916C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8278
SUBJECT: GRB 080916C: Fermi GBM Spectral Analysis
DATE:    08/09/20 23:41:31 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

Alexander van der Horst (NASA/ORAU) and Adam Goldstein (UAH) report on
behalf of the Fermi Gamma-ray Burst Monitor Team:

"We have performed spectral analysis of GRB 080916C (GCN 8245, 8246).
The time averaged spectrum, from 8 keV up to 30 MeV, of the main emission
up to 66 seconds after the burst is best fit by a Band function with
Epeak = 424 +/- 24 keV, alpha = -0.91 +/- 0.02, and beta = -2.08 +/- 0.06.
The fluence (8 keV - 30 MeV) is 1.9e-4 erg/cm^2.

These spectral analysis results are preliminary; the final results will
be published in the GBM GRB Catalog."


GRB_name: GRB080913B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8280
SUBJECT: GRB 080913B:  Fermi GBM detection
DATE:    08/09/21 15:32:20 GMT
FROM:    Bill Paciesas at UAH  <bill.paciesas@nasa.gov>

Bill Paciesas (UAH), Alexander van der Horst (NASA/MSFC) and Adam Goldstein
(UAH), report on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 17:38:31 UT on 13 September 2008, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered and located GRB 080913B (trigger 243020312 / 080913.735).
The on-ground calculated location, using the GBM trigger data,
is RA = 46.3, Dec = -4.6 (J2000 degrees) (equivalent to J2000 3h 05m,
-4d 36'), with an uncertainty of 3.3 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is
currently estimated to be 2 to 3 degrees).  The angle from the Large Area
Telescope (LAT) boresight is 71 degrees.

This GRB was about 140 s long consisting of several peaks with a main
emission period of 30 seconds.  The time-averaged spectrum from T-2 to T+28 s 
is best fit by a power law with exponential cut-off,
with a power-law index of -0.69 +/- 0.16 and a cut-off energy, parameterized as 
Epeak, of 114 +/- 14 keV. The fluence between 50 and 300 keV over these 30 seconds 
is (2.2 +/- 0.5) x 10^-6 erg/cm^2.

The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog."


GRB_name: GRB080922A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8281
SUBJECT: GRB080922: A long GRB detected by INTEGRAL
DATE:    08/09/22 12:15:38 GMT
FROM:    Sandro Mereghetti at IASF/CNR  <sandro@iasf-milano.inaf.it>

S.Mereghetti, A.Paizis (IASF-Milano), D.Gotz (CEA-Saclay), W. Ishibashi, 
V.Beckmann, M. Beck (ISDC, Versoix), and J. Borkowski (CAMK, Torun) on 
behalf of the IBAS Localization Team report:

A GRB lasting about 60 s has been detected by IBAS in IBIS/ISGRI data at 
11:03:36 UT of September 22. The coordinates (J2000)  are:

RA: 270.838 [degrees]
DEC: -22.509 [degrees]

with an uncertainty of 2 arcmin (90% c.l.).

A preliminary analysis gives a peak flux in the 20-200 keV range of about 
1 ph/cmq/s (1-s integration time) and a fluence over the same energy 
range of about 1.5x10e-6 erg/cmq.

A plot of the light curve will be posted at

http://ibas.iasf-milano.inaf.it/IBAS_Results.html

This message can be cited.


GRB_name: GRB080922A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8282
SUBJECT: GRB080922: Swift-XRT upper limit
DATE:    08/09/23 07:16:06 GMT
FROM:    Valentina La Parola at INAF-IASPA  <laparola@ifc.inaf.it>

B. Sbarufatti, V. La Parola, V. Mangano (INAF-IASFPa), on behalf of the Swift-XRT team

  At 2008-09-22 14:54UT Swift performed a TOO observation of the INTEGRAL
burst GRB 080922 (Mereghetti et al., GCN Circ. 8281), 3h52m after the
INTEGRAL trigger.

   No X-ray source was found in or near the IBAS error circle in a 5.9ks
exposure Swift/XRT Photon Counting mode image down to a 3 sigma limiting 0.3-10keV count
rate of 4.3e-3 count/s. Assuming a power-law spectrum of photon index 2
absorbed by the Galactic column density of 1.14e22 cm-2 in the direction
of the burst, this corresponds to an observed 0.3-10keV flux limit of
2.55e-13 erg cm-2 s-1.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB080922A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8283
SUBJECT: GRB 080922: Swift/UVOT Upper Limits
DATE:    08/09/23 14:52:56 GMT
FROM:    Stephen Holland at USRA/NASA/GSFC/SSC  <sholland@milkyway.gsfc.nasa.gov>

S. T. Holland (CRESST/GSFC/USRA) and B. Sbarufatti (INAF-IASFPa)
report on the behalf of the Swift UVOT team:

      The Swift/UVOT observed the field of GRB 080922 starting 13,904 s
(= 3.84 hr) after the INTEGRAL detection (Mereghetti et al. 2008, GCN
Circ. 8281).  We do not find any new source, relative to the DSS or
2MASS, or any variable source inside the INTEGRAL/IBAS error circle.
The 3-sigma upper limits for detecting a source in the co-added
images, using a 2.5 arcsecond radius circular aperture, are:

Filter  T_start   T_stop   Exp(s)     Mag
-----------------------------------------
    v     15,622   15,834     208    >18.9
    b     14,550   26,731     625    >20.6
    u     14,333   31,298     834    >20.3
  uvw1    13,904   30,081    1668    >20.5
  uvm2    15,839   15,853      14    >16.1
  uvw2    14,769   27,419    2341    >20.8
-----------------------------------------

The quoted upper limits have not been corrected for the expected, and
highly uncertain, Galactic extinction along the line of sight
corresponding to a reddening of E_{B-V} = 20 mag (Schlegel, et al.,
1998, ApJS, 500, 525).  All photometry is on the UVOT flight system
described in Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB080916A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8284
SUBJECT: GRB080916A: Suzaku WAM observation of the prompt emission
DATE:    08/09/23 14:59:42 GMT
FROM:    Kazutaka Yamaoka at Aoyama Gakuin U  <yamaoka@phys.aoyama.ac.jp>

M. Suzuki, M. Kokubun, M. Ohno, T. Takahashi (ISAS/JAXA), 
K. Yamaoka, S. Sugita (Aoyama Gakuin U.), Y.E. Nakagawa, T. Tamagawa
(RIKEN), T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata
(Hiroshima U.),  M. Tashiro, Y. Terada, Y. Urata, A. Endo, K. Onda,
N. Kodaka, K. Morigami, T. Sugasahara, W. Iwakiri (Saitama U.),
T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), E. Sonoda, 
M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori (Univ. of Miyazaki),  
S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report:

The long GRB080916A (Swift/BAT trigger #324895; Ziaeepour et al., 
GCN 8237) was detected by the Suzaku Wide-band All-sky Monitor (WAM)
which covers an energy range of 50 keV - 5 MeV at 09:45:19.970 UT (=T0).
The observed light curve shows a single peak at T0+0 s, followed by a second 
 soft peak at ~T0+16 s with a total duration (T90) of about 20 seconds. 
The fluence in 100 - 500 keV was (2.57 +/- 0.32)x10^-6 erg/cm^2. 
The 1-s peak flux measured from T0+0 s was
1.54 (-0.12, +0.25) photons/cm^2/s in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-5s to 
T0+10s is fit by a single power-law with a photon index of 
1.58 +/- 0.29 (chi^2/d.o.f = 13.1/12) in 100 - 500 keV. 
All the quoted errors are at statistical 90% confidence level, in which 
the systematic uncertainties are not included.

The light curves with 1/64 sec time resolution for this burst are now 
available at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html


GRB_name: GRB080922A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8289
SUBJECT: GRB080922, optical upper limit
DATE:    08/09/25 08:27:02 GMT
FROM:    Ryuuji Hara at U of Miyazaki  <ryuu55@astro.miyazaki-u.ac.jp>

R. Hara, H.hayasi, N.Ohmori, K.Kono H. Tanaka, M.Yamauchi, E.Sonoda,
(University of Miyazaki)

We have observed the field covering the error circle of
GRB080922 (GCN 8281, S.Mereghetti et al.) with
the unfiltered CCD camera on the 30-cm telescope at
University of Miyazaki.
The observation was started 11:14:04 UT, 11.7min
after the INTEGRAL trigger time.

We have compared our data of 30 sec exposures
with the USNO-A2.0 catalog,there is no new source
at the reported position.

the upper limits are as follows:
--------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
--------------------------------------------------------------
11:15:19  11:15:49      1        16.7
11:15:19  11:41:35      20       17.1
---------------------------------------------------------------

-- 
----------------------------------------
$B5\:jBg3XBg3X1!(B $B1~MQJ*M}3X@l96(B
$B=$;N2]Dx(B 2$BG/(B
$B86(B $BN6;y(B
ryuu55@astro.miyazaki-u.ac.jp
----------------------------------------


GRB_name: GRB080920A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8290
SUBJECT: GRB 080920: Fermi GBM detection
DATE:    08/09/25 13:55:36 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE), E. Bissaldi (MPE), S. McBreen (MPE) 
report on behalf of the Fermi GBM Team: 

"At 06:25:48 UT on 20 September 2008, the Fermi Gamma-ray Burst Monitor
triggered and located GRB 080920 (trigger 243584749 / 080920268). 
The on-ground calculated location using the Fermi GBM trigger data is 
RA = 124.6, Dec = 1.6 (equivalent to J2000 08h 18m, 01d 36'), 
with a statistical uncertainty of 3.4  degrees 
(radius, 1-sigma containment; there is additionally a systematic 
error which is currently estimated to be 2 to 3 degrees). 
The angle from the Fermi LAT boresight is 16 degrees.

This long GRB comprises one FRED like pulse, starting at T0-6 s.
T90 (25-1000 keV) is about 85 s. The time-averaged spectrum 
from T0-6 to T0+79 s is adequately fit by a power law model 
with index -1.42 +/- 0.06. It can also be fit with a power 
law function with an exponential high energy cutoff. 
The cutoff energy, parameterized as Epeak, is 162 +/- 35 keV. 
In this case the power law index is poorly constrained (-0.63 +/- 0.25).


The fluence in the 25-1000 keV band is 2.4 (+/- 0.5) E-06 erg/cm2 
and the peak flux (25-1000 keV) on the 1 s timescale
is 1.29 (+/- 0.14) ph/cm2/s.  

The spectral analysis results presented above are preliminary; 
final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB080925A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8291
SUBJECT: GRB 080925: Fermi GBM Detection
DATE:    08/09/27 05:56:47 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

Adam Goldstein (UAH), Alexander van der Horst (NASA/ORAU) and Rob Preece
(UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 18:35:55 UT on 25 September 2008, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered and located the bright GRB 080925 (trigger 244060556 /
080925.775). The on-ground calculated location, using the GBM trigger
data, is RA = 96.1, Dec = +18.2 (J2000 degrees, equivalent to 6h 24m,
+18d 12'), with a statistical uncertainty less than 1 degree (radius,
1-sigma containment) and an additional systematic error which is
currently estimated to be 2 to 3 degrees. The angle from the Fermi
Large Area Telescope (LAT) boresight is 38 degrees.

This GRB has several peaks, with T90 (50-300 keV) = 29 s and
T50 (50-300 keV) = 9 s. The time-averaged spectrum (8 keV-1 MeV)
from T0 to T0+16.6 s is best fit by a Band function with
Epeak = 120 +/- 5 keV, alpha = -0.53 +/- 0.05, and beta = -2.26 +/- 0.08.
The fluence (50-300 keV) is 9.7E-6 erg/cm^2.

The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog."


GRB_name: GRB080928A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8292
SUBJECT: GRB 080928: Swift detection of a burst with an optical counterpart
DATE:    08/09/28 15:16:04 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. Sakamoto (NASA/UMBC), S. D. Barthelmy (GSFC),
P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), C. Gronwall (PSU),
C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC),
J. Mao (INAF-OAB), F. E. Marshall (NASA/GSFC),
P. T. O'Brien (U Leicester), K. L. Page (U Leicester),
D. M. Palmer (LANL), A. M. Parsons (GSFC) and
T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:

At 15:01:32 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 080928 (trigger=326115).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 95.084, -55.173 which is 
   RA(J2000) = 06h 20m 20s
   Dec(J2000) = -55d 10' 23"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  This is an image trigger so as usual
the BAT lightcurve shows nothing. 

The XRT began observing the field at 15:04:22.6 UT, 169.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 95.0691, -55.1997 which is equivalent to:
   RA(J2000)  = 06h 20m 16.58s
   Dec(J2000) = -55d 11' 58.9"
with an uncertainty of 4.8 arcseconds (radius, 90% containment). This
location is 100 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 5.77e-09 erg cm^-2 s^-1 (0.2-10
keV). 


UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)
filter starting 179 seconds after the BAT trigger. There is a candidate
afterglow in the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 06:20:16.85 =  95.0702
  DEC(J2000) = -55:11:59.3  = -55.1998
with a 1-sigma error radius of about 0.5 arc sec. This position is 2.3 arc sec. 
from the center of the XRT error circle. The estimated magnitude is 19.2 with a
1-sigma error of about 0.5 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.07. 




Burst Advocate for this burst is T. Sakamoto (Taka.Sakamoto AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB080928A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8293
SUBJECT: GRB 080928A: ROTSE-III Confirmation of Optical Counterpart 
DATE:    08/09/28 15:58:35 GMT
FROM:    Eli Rykoff at UCSB  <erykoff@physics.ucsb.edu>

E.S. Rykoff (UCSB), F. Yuan (U Mich), T.A. McKay (U Mich), report on 
behalf of the ROTSE collaboration:

ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded 
to GRB 080928A (Swift trigger 326115, GCN 8292, Sakamoto et al.). The 
first image was at 15:03:44.9 UT, 132.0 s after the burst (7.9 s after 
the GCN notice time). The unfiltered images are calibrated relative to 
USNO A2.0. Our initial images did not detect the UVOT counterpart to a 
limiting magnitude of ~17.2.  However, after ~500 seconds the source 
brightened to 16.9 mag, and it brightened again at ~2000 s to ~16.2 mag. 
The coordinates of the source are consistent with the UVOT counterpart:

      06:20:17.0      -55:11:58.8    (J2000), with positional 
uncertainty of 1" or better

start UT     mag     mlim(of image)
----------------------------------
15:19:02.3     16.9     16.9


This source is not visible in DSS (second epoch), 2MASS or the MPChecker 
database.

A jpeg image is available at 
http://www.rotse.net/images/gsb326115_3a04_img.jpg

Continuing observations are in progress.


GRB_name: GRB080928A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8294
SUBJECT: GRB 080928, Swift-BAT initial refined analysis
DATE:    08/09/28 23:18:56 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

J. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), C. Guidorzi (INAF-OAB),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
K. L. Page (U Leicester), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+323 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 080928 (trigger #326115)
(Sakamoto, et al., GCN Circ. 8292).  The BAT ground-calculated position is
RA, Dec = 95.063, -55.175 deg, which is 
   RA(J2000)  =  06h 20m 15.1s 
   Dec(J2000) = -55d 10' 29.5" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 84%.
 
The mask-weighted light curve shows that BAT triggered on a weak blip 
that occurred long before the main emission of this burst.  The initial
peak started at ~T-10 sec, peaked at ~T_zero, and returned to baseline
around T+30 sec.  Then a second, slightly larger peak, started at ~T+50
and ended at ~T+130 sec.  Then the main emission started at ~T+170, with
a pair of peaks at ~T+205 and ~T+215 sec.  We currently only have data
downlinked out to T+325 sec and the mask-weighted lightcurve shows
continued emission out to this time.  The flight-generated mask-weighted
lightcurve (lower resolution) shows no further peaks beyond T+325 sec.
The main peak at ~T+210 sec coincides with the peak emission in the
prompt XRT TDRSS lightcurve.
 
The time-averaged spectrum from T+51.1 to T+255.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.80 +- 0.12.  The fluence in the 15-150 keV band is 2.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+202.83 sec in the 15-150 keV band
is 2.1 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 

When we get the remainder of the event-by-event data downlinked,
we will issue revised spectral fit results and a T90.
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/326115/BA/


GRB_name: GRB080928A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8295
SUBJECT: GRB 080928: Enhanced Swift-XRT position
DATE:    08/09/28 23:23:00 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 5367 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 080928, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 95.07029, -55.19958 which is equivalent
to:

RA (J2000): 06h 20m 16.87s
Dec (J2000): -55d 11' 58.5"

with an uncertainty of 1.4 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB080928A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8296
SUBJECT: GRB 080928: GROND DETECTION
DATE:    08/09/29 12:02:04 GMT
FROM:    Andrea Rossi at TLS Tautenburg  <rossi@tls-tautenburg.de>

A. Rossi (Tautenburg Obs.), C. Clemens, J. Greiner, A. Yoldas, T. Kruehler,
R. Filgas (all MPE Garching), A. Kupcu Yoldas (ESO) and
G. Szokoly (Eoetvoes Univ., Budapest) report on behalf of the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405),  mounted at the 2.2m ESO/MPI
telescope at La Silla Observatory (Chile), started observations of the
field of GRB 080928 (Sakamoto et al. GCN #8292) in g'r'i'z'JHK at
04:46:00 UT on 2008-09-29, 13.5 hours after the burst trigger.

We clearly detect the optical afterglow detected by UVOT (Sakamoto et al.
GCN #8292) and ROTSE telescope (Rykoff et al. GCN #8293) in
all optical bands, implying a redshift z<3.5.

Observations continued for 90 min and were repeated at the mid-time
06:00 UT for a total 90 min. Both observations were done during strong wind
and bad seeing (>2").

Calibrating the field on the SDSS standard SA95-149, we derive the following
r' band observed magnitudes:

  midtime(s)    r'    err
------------------------
50507        20.57    0.04   
65807        21.36    0.06   

Our data, when compared to the reported brightness of the afterglow
reported by UVOT, suggest a break between the UVOT and the GROND
measurements.


GRB_name: GRB080928A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8297
SUBJECT: GRB 080928, Swift-BAT final refined analysis
DATE:    08/09/29 12:41:32 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

E. Fenimore (LANL), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+494 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080928 (trigger #326115)
(Sakamoto, et al., GCN Circ. 8292).  The BAT ground-calculated position is
RA, Dec = 95.061, -55.176 deg, which is 
   RA(J2000)  =  06h 20m 14.6s 
   Dec(J2000) = -55d 10' 34.8" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 84%.
 
With all the data downlinked, the mask-weighted light curve shows
that BAT triggered on a weak blip that occurred long before the
main emission of this burst.  The initial peak started at ~T-10 sec,
peaked at ~T_zero, and returned to baseline around T+30 sec.
Then a second, slightly larger peak, started at ~T+50 and ended at ~T+130 sec.
Then the main emission started at ~T+170, with a pair of peaks at ~T+205 and
~T+215 sec.  The emaission tails down to almost background at T+400 sec
at which time Swift started to enter the SAA and the errors on the flux
become large.  T90 (15-350 keV) is 280 +- 30 sec (estimated error
including systematics).
 
The time-averaged spectrum from T+51.1 to T+381.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.77 +- 0.12.  The fluence in the 15-150 keV band is 2.5 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+202.83 sec in the 15-150 keV band
is 2.1 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/326115/BA/


GRB_name: GRB080928A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8298
SUBJECT: GRB 080928: Swift/UVOT observations
DATE:    08/09/29 12:54:16 GMT
FROM:    Paul Kuin at MSSL  <npkuin@googlemail.com>

N. P. M. Kuin (MSSL/UCL), T. Sakamoto (NASA/UMBC),and Stephen
Holland (GSFC) report on behalf of the Swift UVOT team

The Swift UltraViolet/Optical Telescope (UVOT) began observations of
GRB080928 (Swift BAT trigger number 326115, Sakamoto et al., GCN Circ.
8292), on September 28, 2008, at 15:04:15 UT, 161 seconds after the
trigger with a setling exposure in the UVOT v filter.

We detect a new source at position :

RA=06:20:16.836 Dec=-55:11:58.95  (95.07015, -55.199708 deg (J2000)),

with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence).

The initial magnitude observed for GRB080928  is given below for the
first observation in the UVOT v filters:

Filter Tstart(s) Tstop(s)  Exp(s)  Magnitude

wh(fc)  179      279       99.8    19.09 +/- 0.14  7.3-sigma
v (fc)  285      479      193.7    19.07 +/- 0.43  2.5-sigma
uvm2   4227     4427      196.6   >19.47 3-sigma upper limit (weak signal)
uvw1   4432     4632      196.6    18.64 +/- 0.19  5.6-sigma
u      4638     4838      199.8    17.96 +/- 0.09 12.1-sigma
b      4843     5043      199.8    18.40 +/- 0.09 11.9-sigma
uvw2   5255     5455      196.6   >19.89 3-sigma upper limit
v      5460     5660      199.8    18.03 +/- 0.15 7.3-sigma

The upper limits in the UV filters uvw2 and uvm2 indicate an
upper limit to the redshift of z < 1.8. An initial rise is seen
up to about 200s in the white filter event data.

The values quoted above are on the UVOT Photometric System
(Poole et al, 2008, MNRAS 383,627). They are not corrected for the
expected galactic reddening of E(B-V) = 0.067 in the direction of
the burst (Schlegel et al. 1998).


GRB_name: GRB080928A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8299
SUBJECT: GRB 080928: Swift-XRT refined analysis
DATE:    08/09/29 12:56:41 GMT
FROM:    Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>

C. Guidorzi, R. Margutti, J. Mao (INAF-OAB) and T. Sakamoto (GSFC/UMBC)
report on behalf of the Swift-XRT team:

We have analysed the first 7 orbits of Swift-XRT data obtained for
GRB 080928 (Sakamoto et al., GCN Circ. 8292), covering 325 s of Windowed
Timing (WT) mode data and 15.3 ks of Photon  Counting (PC) mode data.
The UVOT-enhanced XRT position was given by Osborne et al. in GCN Circ. 
8295.

The light-curve can be modelled by a broken power-law, with a couple
of bright flares peaking at 210 and 360 s with a FWHM duration of 55
and 35 s and a peak count rate of 420 +/- 10 and 75 +- 3 count s^-1,
respectively. The power-law decay index changes from an initial value
of 1.20 +- 0.03 to 1.7 +- 0.2 after a break time of (11 +- 2) ks
(uncertainties at 1 sigma). The first flare coincides with the main
emission seen by BAT (Fenimore et al. GCN Circ. 8297).

A spectrum extracted from WT data around the first flare, from 176 to 250 s,
can be modelled with an absorbed power-law, with Gamma = 1.45 +- 0.06 and
NH = (1.7 +- 0.2)x1e21 cm^-2, in excess of the Galactic column in this
direction of 5.6e20 cm^-2. Another spectrum extracted around the second
flare, from 300 to 470 s, can be fit with the same model, with
Gamma = 1.85 +- 0.06 and NH = (1.1 +- 0.2)x1e21 cm^-2.
A later spectrum extracted from PC data, from 5 to 47 ks, can be fit with
an absorbed power law with Gamma  = 2.2 +- 0.2 and NH = (1.2 +- 0.4)x1e21
cm^-2. The observed (unabsorbed) flux over this time interval is 8.4x10^-12
(1.2x10^-11) erg cm^-2 s^-1.

If the light-curve continues to decay with the current rate, the count
rate 24 hours after the burst is estimated to be 5.6e-3 count s^-1, which
corresponds to an observed flux of 2.5x10^-13 erg cm^-2 s^-1.

This is an official product of the Swift-XRT team.


GRB_name: GRB080928A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8300
SUBJECT: GRB080928: Gemini-South Absorption Redshift
DATE:    08/09/29 15:31:33 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara@astro.psu.edu>

A. Cucchiara, D. B. Fox (Penn State), S. B. Cenko  (Berkeley) and E. Berger
(Harvard) report on behalf of a larger collaboration:

Starting at 06:54 UT on 2008 September 29 (T0+16h) we observed the optical
counterpart of GRB 080928 (Sakamoto et al., GCN 8292, Rykoff  et al., 
GCN 8293)
using Gemini-South with the GMOS-South spectrograph (R~1200).
We acquired 2x900s spectra which covered the wavelength range 4000A-8000A.

Our spectrum shows a flux cut-off blueward of 4500A indicating a likely DLA
associated with the GRB host galaxy, consistent with a redshift of z ~ 2.6.

We also identify multiple metal absorption features including FeII(2249),
FeII(2260), SiIV(1393), SiIV(1402), CIV(1548), CIV(1550), NiII(1741) and
NiII(1751) at a common redshift of z = 2.49.

Therefore we conclude that GRB080928 occurred in a possible DLA galaxy
at z = 2.49.

We thank the Gemini staff for conducting these observations.

[GCN OPS NOTE(29sep08): Per author's request, the affiliation for EB
was corrected to Harvard.]


GRB_name: GRB080928A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8301
SUBJECT: GRB 080928: VLT redshift
DATE:    08/09/29 16:26:29 GMT
FROM:    Paul Vreeswijk at Dark Cosmology Centre,U.of Copenhagen  <pmv@dark-cosmology.dk>

Paul Vreeswijk, Daniele Malesani, Johan Fynbo (DARK/NBI), Pall
Jakobsson (U. of Iceland), Christina Thoene, Jesper Sollerman, Darach
Watson, Bo Milvang-Jensen (DARK/NBI) report on behalf of a larger
collaboration:

The afterglow of GRB 080928 detected by Swift (Sakamoto et al., GCN
8292, see also Rykoff et al., GCN 8293) was observed with FORS2
mounted on the Antu telescope of ESO's VLT on Cerro Paranal, Chile.
Following an acquisition image, which was started at 6:31 UT on
September 29, 2008 (15.5 hr after the GRB trigger), a single 1800 s
spectrum was secured. It was taken with a 1" slit and the 300V grism,
resulting in an approximate resolution of 11 A, and a useful
wavelength coverage of 3800-9300 A. From the 60 s acquisition image,
we measure an afterglow magnitude of R = 20.4 based on USNO-B1
magnitudes.

The extracted spectrum shows a multitude of significant absorption
lines, which we identify with common resonance lines of mainly MgII
and FeII, originating in at least two absorption systems at z=0.735
and z=1.692. The latter redshift presumably corresponds to that of the
GRB host galaxy. We do not find evidence for a spectral break due to
the Lyman alpha forest down to 3800 A, setting a firm upper limit on
the GRB redshift of z < 2.1. These results are consistent with the
redshift limits set by GROND (Rossi et al., GCN 8296) and UVOT (Kuin
et al., GCN 8298), but not with the value of z=2.49 reported by
Cucchiara et al. (GCN 8300).

The equivalent width of the MgII 2796 line of the z=0.735 system
(EW_rest ~ 4.3 A) is much larger than that of the z=1.692 system. We
note the presence of an R ~ 22 object, not covered by the slit, at
2.6" NNE of the afterglow position, which could possibly be a bright
host galaxy, or the counterpart of the z=0.735 absorber. The slit
serendipitously covers a galaxy 30" away from the afterglow (at
R.A. 06:20:13.35, decl. -55:11:55.0), which shows an apparent emission
line at 6470 A; this can be identified as [OII] 3727 at a redshift of
z=0.736. At this redshift, 2.6 and 30" correspond to projected
distances of 19 and 219 kpc, respectively.

We are grateful for the excellent support from the Paranal observing
staff, in particular Stephane Brillant, Michelle Doherty and Patricia
Guajardo.


GRB_name: GRB080927A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8302
SUBJECT: GRB 080927: Fermi GBM detection
DATE:    08/09/30 15:04:40 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi, S. McBreen and A. von Kienlin (MPE) 
report on behalf of the Fermi GBM Team: 


"At 11:30:32 UT on 27 September 2008, the Fermi Gamma-ray Burst Monitor
triggered and located GRB 080927 (trigger 244207833 / 080927480).
The on-ground calculated location, using the Fermi GBM
trigger data, is RA = 57.8, Dec = +30.0 
(equivalent to J2000 03h 51m, 30d 00'),  
with a statistical uncertainty of 4.0 degrees (radius, 1-sigma 
containment; there is additionally a systematic error which is 
currently estimated to be 2 to 3 degrees). The angle from the 
Fermi LAT boresight is 75 degrees. 

This GRB is singled peaked with an estimated 
T90 (25-1000 keV) of about 25 s. 
The time-averaged spectrum from T0-1.3s to T0+20.2s is 
adequately fit by a simple power law with index -1.5 +/- 0.1.
An improvement in the fit is obtained using the
Band model with Epeak = 40 +/- 10 keV and beta = -1.7 +/- 0.1.
However alpha is poorly constrained.

The fluence (25-1000 keV) in this time interval from the 
power law model is (5.7 +/- 0.2)E-06 erg/cm2.
The 1s peak photon flux measured starting from T0+5.9 
in the 25-1000 keV band is 2.0 +/- 0.1 ph/s/cm2.


The spectral analysis results presented above are preliminary;
the final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB080928A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8303
SUBJECT: GRB 080928: Watcher observations
DATE:    08/10/01 14:22:05 GMT
FROM:    Alejandro Ferrero at U College,Dublin  <alejandro.ferrero@ucd.ie>

Alejandro Ferrero (UCD School of Physics), John French (UCD School of
Physics/ DARK/NBI), and Gary Melady (UCD School of Physics) report on
behalf of a larger collaboration:

We observed the field of GRB 080928 (Sakamoto et al. GCN 8292) with
 the Watcher robotic telescope at Boyden Observatory, South Africa. The
afterglow previously reported (Sakamoto et al. GCN 8292, Rykoff et al.
GCN 8293, Rossi et al. GCN 8296, Kuin et al. GCN 8298) is detected in
 a stacked sequence of 10 unfiltered 120s exposures with an exposure
midtime of 10.56 hrs from the Swift triggger. Comparison with USNO-B1
R-band magnitudes gives a magnitude of 19.37 +/- 0.11 for the optical
afterglow at this time. Comparison with later GROND observations
 (Rossi et al. GCN 8296) indicates a steep decay slope of approx. -3
+/- 0.4 from 10.56 hours to 18.27 hours from the trigger.


GRB_name: GRB080928A
Detection_method: retraction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8304
SUBJECT: GRB080928: redshift retraction
DATE:    08/10/01 15:53:55 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara@astro.psu.edu>

A. Cucchiara and D. B. Fox (Penn State) report on behalf of a larger 
collaboration:

We re-processed the data acquired on GRB080928 in order to reconcile our 
results
with the redshift identification reported by Vreesvijk et al. (GCN 8301).

Upon comparison of our two individual exposures, we cannot confirm the 
presence
of the metal absorption features reported in GCN 8300.  We therefore 
conclude that
the redshift z=2.49 for GRB 080928 reported by us previously is not 
correct.  Line
misidentifications are probably the result of inaccurate sky-line and 
sky-fringe
modeling in extraction of the 1D spectrum.  We retract also the claim of 
a DLA
system at z~2.5.

We confirm the detection of strong MgII doublet and associated MgI 
absorption from
a system at z=1.69, which - as reported by Vreeswijk et al. - represents 
the lower
limit and most likely redshift for GRB 080928.

We apologize for any confusion.


GRB_name: GRB081001A
Detection_method: superAGILE
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8305
SUBJECT: GRB081001: SuperAGILE Localization of a long GRB
DATE:    08/10/01 22:55:08 GMT
FROM:    Marco Feroci at IASF/INAF  <feroci@iasf-roma.inaf.it>

F. Lazzarotto, E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci,
L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda
(INAF/IASF Rome), A. Giuliani, S. Vercellone, A. Chen,
S. Mereghetti, A. Pellizzoni, F. Perotti, F. Fornari, P.
Caraveo (INAF/IASF Milan), A. Bulgarelli, F. Gianotti,
M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi,
M. Galli, (INAF/IASF Bologna), M. Tavani, G. Pucella, F. D'Ammando, V.
Vittorini, A. Argan, A. Trois (INAF/IASF Rome), G. Barbiellini,
F. Longo (INFN Trieste), P. Picozza, A. Morselli (INFN Roma-2),
M. Prest, E. Vallazza (Universita' dell'Insubria), P. Lipari,
D. Zanello (INFN Roma-1), and  P. Giommi, C. Pittori, B. Preger,
P. Santolamazza, F. Verrecchia (ASDC) and L. Salotti (ASI),
on behalf of the AGILE Team, report:

"SuperAGILE detected a gamma ray burst on 1st October 2008, at 21:17:42 
UT. The event had a duration of about 40 s in the 20-60 keV energy range,
with a first 10-s long bright peak, followed by a second broad peak about 
20s apart. Assuming a Crab-like energy spectrum, the peak flux on 1-s 
timescale was about 6 ph/cm2/s or 5E-07 erg/cm2/s (20-60 keV).
The burst position was reconstructed  as (RA, Dec)
(276.576 deg, -8.754 deg), which is:

RA(J2000)  = 18h 26m 18.34s
Dec(J2000) = -8d 45' 14.65"

with an uncertainty of 3' radius. The given uncertainty accounts
for both the statistical and systematic errors.

An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress."

This message may be cited.


GRB_name: GRB081001A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8306
SUBJECT: GRB081001: optical limit from ASH-Centurion
DATE:    08/10/02 02:24:13 GMT
FROM:    Martin Jelinek at Inst.Astrophys.Andalucia,Granada  <mates@iaa.es>

Martin Jelinek, Rene Duffard, Pablo Santos Sanz
and Alberto J. Castro Tirado (IAA CSIC Granada)
report on behalf of a larger collaboration:


We observed the errorbox of the SuperAGILE
GRB081001 (Lazzarotto et al., GCN 8305) with the
40cm ASH-Centurion telescope at Cerro Burek in
Argentina starting at 23:28 UT.

The combined 600s unfiltered image with exposure
mid-time 2.30h after the GRB trigger does not
reveal any new source down to limiting magnitude
of ~19.0 in comparison to the Digitized Sky
Survey.

This message may be cited.


GRB_name: GRB081001A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8307
SUBJECT: GRB 081001: Swift-XRT position 
DATE:    08/10/02 16:14:48 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page (U. Leicester) and H.A. Krimm (CRESST/GSFC/USRA) report on 
behalf of the Swift-XRT team:

Swift-XRT started observing the field of the SuperAGILE GRB 081001 
(Lazzarotto et al., GCN Circ. 8305) 15.5 ks after the trigger. A single, 
fading source was identified within the SuperAGILE error circle, which we 
identify as the X-ray afterglow.

Using 4307 s of XRT Photon Counting mode data and 4 UVOT images, we find 
an astrometrically corrected X-ray position (using the XRT-UVOT alignment 
and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 
276.59076, -8.71903 which is equivalent to:

RA (J2000):   18 26 21.78
Dec (J2000): -08 43 08.5

with an uncertainty of 2.0 arcsec (radius, 90% confidence).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081001A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8308
SUBJECT: GRB 081001: Swift UVOT Observations
DATE:    08/10/02 17:29:21 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU), and H.A. Krimm (CRESST/GSFC/USRA) report on
behalf of the Swift UVOT team:

The Swift/UVOT began observations of the field of GRB 081001 14.5 ks
after the SuperAGILE dectection (Lazzarotto et al., GCN
Circ. 8305). No afterglow is detected within the Swift XRT error
circle (Page et al., GCN 8307) in any of the observed UVOT filters.

UVOT magnitude 3-sigma upper limits are reported in the following
table:

Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
v         16285    22214      350       > 19.84
b         15213    21209      416       > 20.90
u         14997    20992      416       > 20.51
uvw1      14568    20776      834       > 20.84
uvm2      16502    16696      191       > 19.81
uvw2      15431    22064     1670       > 21.65

The quoted upper limits have not been corrected for the large expected
Galactic extinction along the line of sight of E(B-V) = 2.63 mag
(Schlegel et al., 1998).  All photometry is on the UVOT photometry system
described in Poole et al. (2008, MNRAS, 383, 627).


GRB_name: GRB080925A
Detection_method: Suzaku WAM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8309
SUBJECT: GRB 080925: Suzaku WAM observation of the prompt emission
DATE:    08/10/03 01:10:38 GMT
FROM:    Kazutaka Yamaoka at Aoyama Gakuin U  <yamaoka@phys.aoyama.ac.jp>

T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), S. Sugita, 
K. Yamaoka (Aoyama Gakuin U.),  M. Ohno, M. Kokubun, M. Suzuki, 
T. Takahashi (ISAS/JAXA), Y.E. Nakagawa, T. Tamagawa (RIKEN), 
T. Uehara, T. Takahashi, Y. Fukazawa, C. Kira, Y. Hanabata (Hiroshima U.),
M. Tashiro, Y. Terada, Y. Urata, A. Endo, K. Onda, 
N. Kodaka, K. Morigami, T. Sugasahara, W. Iwakiri (Saitama U.),
E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara, N. Ohmori (Univ. of Miyazaki),
S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report:

The long GRB080925 (Fermi-GBM triggered ; Goldstein et al., GCN 
8291) triggered the the Suzaku Wide-band  All-sky Monitor (WAM) 
which covers an energy range of 50 keV - 5 MeV at 18:35:56.853
UT (=T0). 

The observed light curve shows a multi-peaked structure (peaks at 
T0+1s, T0+5s, and T0+14s) with a duration (T90) of about 15 seconds. 
The fluence in 100 - 1000 keV was 7.3(+0.3, -0.2) X 10^-6 erg/cm^2. 
The 1-s peak flux measured from T0+5s was 2.8 photons/cm^2/s 
in the same energy range.

Preliminary result shows that the time-averaged spectrum from T0-10s 
to T0+20s is well fitted by a single power-law with a photon index 
of 2.33(+0.16/-0.18) (chi^2/d.o.f = 36.0/42) in the 150-1000 keV 
energy band. All the quoted errors are at statistical 90% confidence 
level, in which the systematic uncertainties are not included.

The light curves for this burst are availabel at:
http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trg/grb_table.html


GRB_name: GRB081001A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8310
SUBJECT: GRB 081001: Observations from OSN
DATE:    08/10/03 01:29:37 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (ESO, Santiago), F. Aceituno, M. Jelnek,
J. Gorosabel and A.J. Castro-Tirado (IAA-CSIC, Granada) on
behalf of a larger collaboration report,

We have observed the field of the SuperAGILE GRB 081001
(Lazzarotto et al., GCN 8305) and in particular the Swift/XRT
error box (Page et al., GCN 8307) from the 1.5m OSN telescope
at Sierra Nevada Observatory in Granada (Spain). The
observation consisted of 3x300s I-band exposures with a mean
time of Oct 2.8348 UT (22.7 hours after the burst). We detect just
one source on the edge of the XRT error box, located at the
following coordinates (J2000 +/- 0.7"):
R.A.: 18:26:21.65
Dec.: -08:43:07.6
With a magnitude of I = 19.90+/-0.26 as compared to several
USNO-B1 stars. A finding chart (with the object is marked as A)
can be found in:
http://www.sc.eso.org/~adeugart/GRB/081001/081001.gif
No variability can be established at this point. Rechecking of the
unfiltered image reported by Jelnek et al. (GCN 8306) does not
show any significant emission at the location of the object. Further
observations would be needed in order to determine any relation
of this source with the GRB.


GRB_name: GRB081003A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8314
SUBJECT: GRB 081003: A long GRB discovered by INTEGRAL
DATE:    08/10/03 14:53:11 GMT
FROM:    Sandro Mereghetti at IASF/CNR  <sandro@iasf-milano.inaf.it>

S.Mereghetti, A.Paizis (IASF-Milano), D.Gotz (CEA-Saclay), F. Fontani, 
V.Beckmann, M. Beck (ISDC, Versoix), and J. Borkowski (CAMK, Torun) on 
behalf of the IBAS Localization Team report:

A GRB lasting about 30 s has been detected by IBAS in IBIS/ISGRI data at 
13:46:12 UT of October 3. The coordinates (J2000)  are:

RA = 262.3758 [degrees]
DEC= 16.566 [degrees]

with an uncertainty of 2 arcmin (90% c.l.).

A preliminary analysis gives a peak flux in the 20-200 keV range of about 
0.3 ph/cmq/s (1-s integration time) and a fluence over the same energy 
range of about 4x10e-7 erg/cmq.

A plot of the light curve will be posted at

http://ibas.iasf-milano.inaf.it/IBAS_Results.html

This message can be cited.


GRB_name: GRB080928A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8316
SUBJECT: GRB 080928:  Fermi GBM detection
DATE:    08/10/03 16:17:37 GMT
FROM:    Bill Paciesas at UAH  <bill.paciesas@nasa.gov>

Bill Paciesas, Michael Briggs and Rob Preece
(UAH), report on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 15:04:56 UT on 28 September 2008, the Fermi Gamma-Ray Burst Monitor
(GBM) triggered and located GRB 080928 (trigger 244307097 / 080928.628),
which had triggered the Swift BAT ~204 s earlier (Sakamoto et al. GCN 8292).
The on-ground calculated location, using the GBM trigger data, is RA = 93.9,
Dec = -53.1 (+/- 4.9)(J2000 degrees), with an uncertainty of 4.9 degrees
(radius, 1-sigma containment, statistical only; there is additionally a
systematic error which is currently estimated to be 2 to 3 degrees),
consistent with the Swift location (Sakamoto et al. GCN 8292; Osborne et al.
8295).

The emission detected by GBM lasted about 87 s with the strongest emission
in the first 20 s, and is approximately coincident with the main emission
detected by Swift (Cummings et al. GCN 8294).  The time-averaged spectrum
from T-5 to T+24 s can be fit by a power-law with an index of -1.80 +/-
0.08. The fluence between 50 and 300 keV over these 87 seconds is (1.5 +/-
.1) x 10^-6 erg/cm^2.

The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog."


GRB_name: GRB081003B
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8317
SUBJECT: GRB 081003B: a long GRB detected with INTEGRAL
DATE:    08/10/03 22:08:37 GMT
FROM:    Diego Gotz at CEA  <diego.gotz@cea.fr>

D.Gotz (CEA-Saclay), S.Mereghetti, A.Paizis (IASF-Milano),  F. Fontani,
V.Beckmann, M. Beck (ISDC, Versoix), and J. Borkowski (CAMK, Torun) on
behalf of the IBAS Localization Team report:

A GRB lasting about 30 s has been detected by IBAS in IBIS/ISGRI data at
20:48:08 UT of October 3. The coordinates (J2000)  are:

RA = 285.0256 [degrees]
DEC= +16.6914[degrees]

with an uncertainty of 1.5 arcmin (90% c.l.).

A preliminary analysis gives a peak flux in the 20-200 keV range of  
about
3 ph/cmq/s (1-s integration time) and a fluence over the same energy
range of about 6x10e-6 erg/cmq.

A plot of the light curve will be posted at

http://ibas.iasf-milano.inaf.it/IBAS_Results.html

This message can be cited.


GRB_name: GRB081003A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8319
SUBJECT: GRB 081003A: Swift-XRT Team position and analysis 
DATE:    08/10/03 23:31:33 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page, A.P. Beardmore (U. Leicester) and H.A. Krimm (CRESST/GSFC/USRA) 
report on behalf of the Swift-XRT team:

Swift began observing the field of the INTEGRAL GRB 081003A (Mereghetti et 
al., GCN Circ. 8314) 7.6 ks after the trigger. In 1.8 ks of Photon 
Counting mode data, we detect a single source within the INTEGRAL error 
circle at a position of RA, Dec = 262.39082, 16.57103, which is equivalent 
to

RA(J2000):   17 29 33.80
Dec(J2000): +16 34 15.70

with an uncertainty of 3.9 arcsec (radius, 90% containment). The source 
has a count rate of ~0.026 during this observation.

The spectrum of the source can be fitted by an absorbed power-law, with 
Gamma = 3.6 +1.6/-1.2 and NH = (7 +6/-4)x10^21 cm^-2, compared to the 
Galctic value of 6.67x10^20 cm^-2. It is not possible to determine whether 
this source is fading given the current statistics.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081003B
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8320
SUBJECT: GRB081003B: Optical limits from Spain
DATE:    08/10/03 23:38:44 GMT
FROM:    Martin Jelinek at Inst.Astrophys.Andalucia,Granada  <mates@iaa.es>

Martin Jelinek, Javier Gorosabel, Fran Aceituno, 
Alberto Castro-Tirado (IAA CSIC Granada) and
Antonio de Ugarte Postigo (ESO Santiago)

report on behalf of a larger collaboration:


We observed the error box of the INTEGRAL GRB081003B (Gotz et
al., GCN8317) with the 30cm BOOTES-1B in El Arenosillo and
with the 1.5m telescope at Observatorio Sierra Nevada.

BOOTES started obtaining unfiltered images at 20:48:49UT (41s
after the GRB trigeer), single images have a detection limit
of ~14 mag. The combination of the first 32 images with an
exposure mean time of 80s after the GRB has a limit of
~17.6mag (calibrated against GSC2). Neither shows any new
sources within the GRB errorbox.

The 1.5m telescope took a single I-band 300s exposure starting
at 21:21:59 (mid exposure ~26.5 min after the GRB), this image
does not reveal any new source in comparison with DSS-IR, but
goes deeper. Further comparison image would be needed to
exploit full potential of this observation.

This message may be cited.


GRB_name: GRB081001A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8322
SUBJECT: GRB 081001: Further observations from OSN
DATE:    08/10/04 01:07:27 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (ESO, Santiago), F. Aceituno, M. Jelnek,
J. Gorosabel and A.J. Castro-Tirado (IAA-CSIC, Granada) on
behalf of a larger collaboration report,

We have observed again the field of GRB 081001 (Lazzarotto et
al., GCN 8305, Page et al., GCN 8307) from the 1.5m OSN
telescope at Sierra Nevada Observatory in Granada (Spain). In a
combined 5x300s exposure in I-band we still detect the source
reported in our previous GCN (de Ugarte Postigo et al. GCN
8310) with no variation in brightness indicating that it is
probably unrelated with the GRB. No further source is detected
within the XRT error box. The 3-sigma limiting magnitudes of
the images obtained from OSN are I > 20.7  0.95 days after the
burst and I > 21.2 1.94 days after the burst.


GRB_name: GRB081003A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8323
SUBJECT: GRB 081003A: OSN optical observations
DATE:    08/10/04 06:08:03 GMT
FROM:    Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct@iaa.es>

A. de Ugarte Postigo (ESO, Santiago), F. J. Aceituno, M. Jelnek, J.
Gorosabel and A.J. Castro-Tirado (IAA-CSIC, Granada) on behalf of a larger
collaboration report:

"We have observed the field of GRB 081003A detected by INTEGRAL
(Mereghetti et al. GCN 8314) with the 1.5m OSN telescope at Sierra Nevada
Observatory (Granada, Spain). The observations consisted of 6x300s in
I-band, 2x300s in R-band and 2x300s in V-band (5.07, 6.17 and 5.31h after
the burst trigger respectively). We do not detect any new optical source
within the Swift/XRT error box (Page et al. GCN 8319) down to 3-sigma
limiting magnitudes of I > 22.0 and R > 22.5. We note, however that there
could be a marginal object (with low S/N significance in the I-band frame)
at coordinates (J2000): R.A.: 17:29:33.85, Dec.: +16:34:14.1 (+/-0.7"),
consistent with the XRT error box. Deeper observations would be needed in
order to confirm the reality of this source."


GRB_name: GRB081003B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8324
SUBJECT: GRB 081003B: Swift-XRT upper limit 
DATE:    08/10/04 19:23:35 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page (U. Leicester) & C.B. Markwardt (CRESST/GSFC/UMD) report on 
behalf of the Swift-XRT team:

Swift-XRT performed a Target of Opportunity observation of the INTEGRAL 
GRB 081003B (Gotz et al., GCN Circ. 8317), starting ~29 ks after the 
trigger. No source is detected within or near to the INTEGRAL error circle 
during a 3.6 ks Photon Counting mode observation. The 3-sigma upper limit 
on the count rate is 0.002 count s^-1, corresponding to an approximate 
observed 0.3-10 keV flux of 1x10^-13 erg cm^-2 s^-1 (using a standard 
counts to flux conversion factor).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081003B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8326
SUBJECT: GRB 081003B: TAROT Calern observatory optical observations
DATE:    08/10/06 10:38:46 GMT
FROM:    Alain Klotz at CESR-CNRS  <Alain.Klotz@free.fr>

Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report:

We imaged the field of GRB 081003 detected by INTEGRAL
(trigger 5361) with the TAROT robotic telescope (D=25cm)
located at the Calern observatory, France.

2008-10-03T20:48:45.809

The observations started 29.7s after the GRB trigger
(7s after the notice) when the gamma emission was
still active. The elevation of the field decreased
from 41 degrees above horizon and weather conditions
were good.

The date of trigger : t0 = 2008-10-03T20:48:16.09

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT at the position provived
by Gotz (GCNC 8317) with a limiting magnitude of:

t0+29.7s to t0+89.7s : R > 16.9

The second image is 30.0s exposure in tracking mode:
t0+97.0s to t0+127.0s : R > 17.4

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

N.B. Galactic coordinates are lon= 48.80 lat= +5.63
and the galactic extinction in R band is 2.0 magnitudes
estimated from D. Schlegel et al. 1998ApJ...500..525S.

This message may be cited.


GRB_name: GRB081003C
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8329
SUBJECT: GRB081003C: GLAST Burst Monitor detection
DATE:    08/10/06 23:54:14 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

A.J. van der Horst (NASA/ORAU) reports on behalf of the Fermi GBM Team:

"At 15:27:17 UT on 3 October 2008, the Fermi GBM triggered and located
GRB 081003C (trigger 244740438 / 081003.644).
The on-ground calculated location, using the GBM trigger data, is
RA = 270.0, Dec = +20.9 (J2000 degrees, equivalent to 18h 00m, +20d 54'),
with an uncertainty of 3.7 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is
currently estimated to be 2 to 3 degrees). The angle from the Fermi
LAT boresight is 48 degrees.

This GRB has several peaks, with T90 (50-300 keV) = 67 s and
T50 (50-300 keV) = 31 s. The time-averaged spectrum (8-1000 keV) from
T0-4 to T0+51 s is best fit by a power law with index = -1.41 +/- 0.06.
The fluence (50-300 keV) is 5.4E-6 erg/cm^2.

The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog."


GRB_name: GRB081007A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8330
SUBJECT: GRB 081007: Swift detection of a burst with optical afterglow
DATE:    08/10/07 05:41:22 GMT
FROM:    Wayne Baumgartner at GSFC  <wayne@milkyway.gsfc.nasa.gov>

W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (NASA/UMBC),
P. A. Evans (U Leicester), S. D. Hunsberger (PSU),
C. B. Markwardt (CRESST/GSFC/UMD), K. L. Page (U Leicester),
D. M. Palmer (LANL), A. M. Parsons (GSFC), M. Stamatikos (NASA/ORAU),
R. L. C. Starling (U Leicester) and M. C. Stroh (PSU) report on behalf
of the Swift Team:

At 05:23:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081007 (trigger=330856).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 339.976, -40.136 which is 
   RA(J2000) = 22h 39m 54s
   Dec(J2000) = -40d 08' 08"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure with a duration of about 25 sec.  The peak count rate
was 1500 counts/sec (15-350 keV), at 1 sec after the trigger. 

The XRT began observing the field at 05:25:32.1 UT, 99.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 339.96077, -40.14675 which
is equivalent to:
   RA(J2000)  = 22h 39m 50.58s
   Dec(J2000) = -40d 08' 48.3"
with an uncertainty of 3.1 arcseconds (radius, 90% containment). This
location is 57 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.38e+20 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 1.53e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm)
filter starting 108 seconds after the BAT trigger. There is a candidate
afterglow in the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 22:39:50.40 = 339.9600
  DEC(J2000) = -40:08:48.8  = -40.1469
with a 1-sigma error radius of about 0.5 arc sec. This position is 2.2 arc sec. 
from the center of the XRT error circle. The estimated magnitude is 17.0 with a
1-sigma error of about 0.5 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.01. 

Burst Advocate for this burst is W. H. Baumgartner (wayne AT milkyway.gsfc.nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081007A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8331
SUBJECT: GRB 081007: REM NIR and optical counterpart
DATE:    08/10/07 05:48:11 GMT
FROM:    Stefano Covino at Brera Astronomical Observatory  <stefano.covino@brera.inaf.it>

S. Covino, L.A. Antonelli, L. Calzoletti,  S. Campana, G.  
Chincarini,  M.L. Conciatore, S. Cutini,  V. D'Elia,  F. D'Alessio,  
P. D'Avanzo,  F. Fiore, D. Fugazza, P. Goldoni, D. Guetta, C.  
Guidorzi, G.L.  Israel, E. Maiorano, N. Masetti, A. Melandri, E.  
Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L.  Stella,   
G.  Stratta, G. Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F.  
Vitali report on  behalf of the REM team:


The robotic 60-cm REM telescope located at La Silla (Chile) observed  
automatically the field of the GRB 081007 (Baumgartner et al. GCN  
8330) starting about 35s s from the GRB alert (46s from the GRB time)  
with the VRIJHK bands.

We detect a source with coordinates RA,DEC =  
(22:39:50.39,-40:08:49.1) consistent with the UVOT source at H~14.2.  
The source is slowly fading after the first observations.

Further observations are in progress.


GRB_name: GRB081007A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8332
SUBJECT: GRB 081007, SMARTS optical/IR afterglow observations
DATE:    08/10/07 06:58:55 GMT
FROM:    Bethany Cobb at Yale U  <cobb@astro.yale.edu>

B. E. Cobb (UC Berkeley) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 081007
(GCN 8330, Baumgartner et al.), starting 23 minutes post-burst
in BVRIJHK.

In the R-band, the GRB afterglow (GCN 8330, Baumgartner et al.
& GCN 8331, Covino et al.) appears to fade by approximately 0.6 magnitudes
between 23 minutes and 56 minutes post-burst, indicating
a decay rate of alpha = -0.6 (where afterglow flux is proportional to
t^alpha).

Observations of this burst are continuing.


GRB_name: GRB081007A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8333
SUBJECT: GRB 081007, Faulkes Telescope North optical observations
DATE:    08/10/07 07:30:58 GMT
FROM:    James Smith at ARI,Liverpool John Moors U  <rjs@astro.livjm.ac.uk>

R.J. Smith, A. Melandri, I.A. Steele, D.F. Bersier, C.G. Mundell,
(Liverpool JMU), A. Gomboc (Ljubljana), C. Guidorzi (INAF-OAB)
on behalf of a larger collaboration reports:

The robotic 2m Faulkes Telescope North located in Hawaii observed
the field of the GRB 081007 (Baumgartner et al. GCN 8330) starting
automatically as soon as the target rose above the observable horizon
about 17 minutes after the GRB time.

A fading optical source is detected at the XRT position reported by
(Baumgartner et al. GCN 8330). Over the period from 0.2 - 1 hour after the
burst, the OT is seen to fade in both R and I with a flux power law slope
of -0.7.

Filter  Mag  T_mid[min]
-----------------------------
R       17.9 +/- 0.4 17.50
R       18.6 +/- 0.4 46.66

I       17.1 +/- 0.4 21.55
I       17.6 +/- 0.4 39.38
-----------------------------


The calibration was performed using the R2 and I magnitudes of the
USNOB-1 catalogue field star at 22:39:43 -40:10:15.3 J2000. A equivalent
amount of B-band data in which the source is detected have also been
obtained and are being analysed. Further observations are ongoing.


GRB_name: GRB081007A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8334
SUBJECT: GRB 081007: Enhanced Swift-XRT position
DATE:    08/10/07 08:11:54 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3344 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 081007, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 339.96031, -40.14731 which is equivalent
to:

RA (J2000): 22h 39m 50.48s
Dec (J2000): -40d 08' 50.3"

with an uncertainty of 1.8 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081007A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8335
SUBJECT: GRB 081007:  Gemini-south redshift
DATE:    08/10/07 13:46:48 GMT
FROM:    Edo Berger at Princton U  <eberger@astro.princeton.edu>

E. Berger (Harvard), D. B. Fox, A. Cucchiara (Penn State), and S. B. Cenko 
(UC Berkeley) report on behalf of a larger collaboration:

"Starting on 2008 October 7.276 UT (73 min after the burst) we observed 
the optical counterpart of GRB 081007 (GCN 8330) using GMOS on the 
Gemini-South 8-m telescope.  Two 900-sec exposures were obtained covering 
a wavlength range of 4600-7400A.  We identify two absorption features at 
6016.7 and 6070.3 A, as well as a weak emission line at 5700.9 A, which 
correspond to the CaII H&K and [OII]3727 lines at a redshift of 
z=0.5295+/-0.0001."


GRB_name: GRB081007A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8336
SUBJECT: GRB 081007: Swift-XRT Team refined analysis
DATE:    08/10/07 18:37:29 GMT
FROM:    Kim Page at U.of Leicester  <kpa@star.le.ac.uk>

K.L. Page (U. Leicester) & W.H. Baumgartner (GSFC/UMBC) report on behalf 
of the Swift-XRT team:

We have analysed the XRT data obtained so far for GRB 081007 (Baumgartner 
et al., GCN Circ. 8330), consisting of 70 s of Windowed Timing (WT) mode 
and 8 ks of Photon Counting mode data. The UVOT-enhanced position was 
given by Beardmore et al. in GCN Circ. 8334

The X-ray light-curve showed an initial steep decay with alpha = 4.0 +/- 
0.2 until about 230 s after the burst, at which time the slope flattened 
to 0.74 +/- 0.05.

The WT spectrum can be fitted by a steep absorbed power-law, with Gamma = 
3.00 +0.27/-0.24 and NH = (6.6 +/- 1.1)e21 cm^-2 at z = 0.5295 (Berger, 
Fox & Cenko, GCN Circ. 8335), in addition to the Galactic value (at z=0) 
of 1.4e20 cm^-2. The observed (unabsorbed) flux over this time (105-176 s 
after the trigger) is 3.21e-10 (1.01e-9) erg cm^-2 s^-1.

If the decay continues at a slope of 0.74, the predicted count rate at 24 
hours after the burst is 0.019 count s^-1, corresponding to an observed 
(unabsorbed) flux of 7.6e-13 (1.2e-12) erg cm^-2 s^-1.

The results of the automatic analysis of the XRT data are available at 
http://www.swift.ac.uk/xrt_products

This is an official product of the Swift-XRT team.


GRB_name: GRB081007A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8337
SUBJECT: GRB 081007: Early RAPTOR measurements of optical counterpart
DATE:    08/10/07 19:56:45 GMT
FROM:    James Wren at LANL  <jwren@nis.lanl.gov>

J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis, B. Norman
of Los Alamos National Laboratory report:

The RAPTOR telescope system responded to Swift trigger
330856 (Baumgartner et al., GCN 8330) under fair observing conditions.
Our narrow-field instruments began observing the location at
05:24:17.13 UTC, 24.4 s after the Swift trigger and during the end
of the Gamma-Ray emitting interval.  We detect the optical counterpart
reported by Baumgartner et al. (GCN 8330) and Covino et al. (GCN 8331).
We first detect the counterpart at R~16.4 at approximately 90s after
the Swift trigger time.  The counterpart brightens over the next 50
seconds to magnitude R~15.4 and then begins fading steadily.  Our
unfiltered images were calibrated against the USNO-B1 R-band.  The
following table gives selected observations, not corrected for
extinction, from this event.

t-mid(s)    exp(s)     mag     mag-err
--------------------------------------------
90.31        5.0      16.43    0.22
139.58      10.0      15.38    0.06
367.83      30.0      16.75    0.20
685.42      30.0      17.28    0.19


GRB_name: GRB081007A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8338
SUBJECT: GRB 081007, Swift-BAT refined analysis
DATE:    08/10/07 20:01:57 GMT
FROM:    Wayne Baumgartner at GSFC  <wayne@milkyway.gsfc.nasa.gov>

GRB 081007, Swift-BAT refined analysis

C. M. Markwardt (UMD/GSFC),
S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL),
N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA),
K. McLean (GSFC/UMD),
D. M. Palmer (LANL),
A. M. Parsons (GSFC),
T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC),
T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):

Using the data set from T-120 to T+182 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 081007 (trigger
#330856) (Baumgartner et al., GCN Circ. 8330).  The BAT
ground-calculated position is RA, Dec = 339.963, -40.146 deg which is
     RA(J2000)  =  22h 39m 51.1s
     Dec(J2000) = -40d 08' 44.8"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90%
containment).  The partial coding was 28%.

The mask-weighted light curve shows a large peak of approximately 9
seconds duration at T+0.  This peak is seen mostly below 50 keV; a
cutoff-powerlaw model fit yields an Epeak of approximately 12 keV.
T90 (15-350 keV) is 10.0 +- 4.5 sec (estimated error including
systematics).

The time-averaged spectrum from T-6.9 to T+7.1 sec is best fit by a
simple power-law model.  The power law index of the time-averaged
spectrum is 2.51 +- 0.20.  The fluence in the 15-150 keV band is 7.1
+- 0.8 x 10^-07 erg/cm2.  The 1-sec peak photon flux measured from
T+1.10 sec in the 15-150 keV band is 2.6 +- 0.4 ph/cm2/sec.  All the
quoted errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/330856/BA/

We note that the fluence ratio in a simple power-law fit between the
25-50 keV band and the 50-100 keV band is 1.43.  This fluence ratio is
larger than 1.32 which can be achieved with a Band function of
alpha=-1.0, beta=-2.5, and Epeak=30 keV.  Thus, preliminary analysis
shows that Epeak of the burst is very likely around or below 30 keV.
Therefore the burst can be classified as an X-ray flash (e.g. Sakamoto
et al. ApJ, 679, 570).


GRB_name: GRB081007A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8339
SUBJECT: GRB 081007, SMARTS optical afterglow observations
DATE:    08/10/08 01:49:15 GMT
FROM:    Bethany Cobb at Yale U  <bcobb@astro.berkeley.edu>

B. E. Cobb (UC Berkeley) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
continued to obtain optical/IR imaging of the error region of GRB 081007
(GCN 8330, Baumgartner et al.) following GCN 8332.

At a mid-exposure time of 2008-10-07 06:04 UT (40 minutes post-burst),
the GRB afterglow (GCN 8330, Baumgartner et al.) had the following
magnitudes:
B = 19.36 +/- 0.04
R = 18.37 +/- 0.03
I = 17.73 +/- 0.03

Observations were obtained under non-photometric conditions.  These
preliminary magnitudes are calibrated against several USNO-B1.0 stars in
the field, so there is likely an additional photometric calibration error
of ~0.2 magnitudes.

From 23 minutes to 112 minutes post-burst the decay rate of the
afterglow remains at alpha = -0.6 (where afterglow flux is proportional to
t^alpha) in all our optical colors.

Further observations of this burst are planned.


GRB_name: GRB081007A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8340
SUBJECT: GRB081007: Swift/UVOT Observations
DATE:    08/10/08 12:40:42 GMT
FROM:    Peter Brown at PSU  <pbrown@astro.psu.edu>

P. J. Brown (PSU) and W. H. Baumgartner (GSFC/UMGC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT observed the field of GRB 081007
starting about 109 s after the BAT detection
(Baumgartner et al., GCN Circ. 8330).  We report additional
detections and 3 sigma upper limits of the fading afterglow
(where T_start and T_stop represent the
elapsed time since the BAT trigger in seconds).

Filter  T_start(s) T_stop  Exp(s)   Mag or 3 Sigma Limit
uvw2    725        1508    40       >18.8
uvm2    621        1394    59       >18.8
uvw1    646        1419    59       >19.3
u       670        1443    59       18.5 +/- 0.2
b       695        1468    39       19.1 +/- 0.2
v       215        615     394      17.5 +/- 0.1
v       969        1369    393      18.6 +/- 0.1
white   109        209     98       17.0 +/- 0.1
white   862        962     98       18.8 +/- 0.1

The above magnitudes are not corrected for the Galactic extinction
corresponding to a reddening of E(B-V) = 0.015 mag (Schlegel et al.,
1998, ApJS, 500, 525).  The photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383,627).


GRB_name: GRB081006A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8341
SUBJECT: GRB081006: Fermi GBM detection
DATE:    08/10/08 19:09:04 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

A.J. van der Horst (NASA/ORAU) reports on behalf of the Fermi GBM Team:

"At 14:29:34 UT on 6 October 2008, the Fermi GBM triggered and located
GRB 081006 (trigger 244996175 / 081006.604).
The on-ground calculated location, using the GBM trigger data, is
RA = 142.4, Dec = -67.4 (J2000 degrees, equivalent to 9h 30m, -67d 24'),
with an uncertainty of 4.5 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is
currently estimated to be 2 to 3 degrees). The angle from the Fermi
LAT boresight is 16 degrees.

This GRB is ~7 seconds long. The time-averaged spectrum (8 keV-30 MeV)
from T0-3.8 to T0+3.3 s is best fit by a Band function with
alpha = -0.77 +/- 0.24, beta = -1.80 +/- 0.22 and Epeak = 1135 +/- 826 keV.
The value of Epeak is not well constrained, but the Band function
provides a significantly better fit than a single power law or a power
law with exponential cutoff. The fluence (50-300 keV) is 7.1E-7 erg/cm^2.

The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog."


GRB_name: GRB081006B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8342
SUBJECT: GRB081006B: Fermi GBM detection
DATE:    08/10/08 19:10:46 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

A.J. van der Horst (NASA/ORAU) reports on behalf of the Fermi GBM Team:

"At 20:55:35 UT on 6 October 2008, the Fermi GBM triggered and located
GRB 081006B (trigger 245019336 / 081006.872).
The on-ground calculated location, using the GBM trigger data, is
RA = 144.9, Dec = -57.5 (J2000 degrees, equivalent to 9h 40m, -57d 30'),
with an uncertainty of 9.3 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic error which is
currently estimated to be 2 to 3 degrees). The angle from the Fermi
LAT boresight is 3 degrees.

This GRB is ~9 seconds long. The time-averaged spectrum (8-1000 keV) from
T0-2.6 to T0+5.6 s is best fit by a power law with index = -1.30 +/- 0.09.
The fluence (50-300 keV) is 7.3E-7 erg/cm^2.

The spectral analysis results presented above are preliminary; the final
results will be published in the GBM GRB Catalog."


GRB_name: GRB081008A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8343
SUBJECT: GRB 081008: ROTSE-III Detection of Optical Counterpart 
DATE:    08/10/08 20:04:04 GMT
FROM:    Eli Rykoff at UCSB  <erykoff@physics.ucsb.edu>

E.S. Rykoff (UCSB), report on behalf of the ROTSE collaboration:

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, 
responded to GRB 081008 (Swift trigger 331093). The first image was at 
19:58:51.3 UT, 41.9 s after the burst (8.3 s after the GCN notice time). 
The unfiltered images are calibrated relative to USNO A2.0. We detect a 
14.5 magnitude, brightening source with coordinates:

      18:39:50.0      -57:25:52.0    (J2000), with positional 
uncertainty of 1" or better

start UT     mag     mlim(of image)
----------------------------------
19:58:51.3     14.5     16.2


This source is not visible in DSS (second epoch), 2MASS or the MPChecker 
database.

A jpeg image is available at 
http://www.rotse.net/images/gsb331093_3c00_img.jpg

Continuing observations are in progress.


GRB_name: GRB081008A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8344
SUBJECT: GRB 081008: Swift detection of a burst with optical afterglow
DATE:    08/10/08 20:12:50 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

J. L. Racusin (PSU), W. H. Baumgartner (GSFC/UMBC), P. J. Brown (PSU),
D. N. Burrows (PSU), P. A. Evans (U Leicester), D. Grupe (PSU),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), V. La Parola (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
J. P. Osborne (U Leicester), A. M. Parsons (GSFC),
M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester),
G. Tagliaferri (INAF-OAB), T. N. Ukwatta (GSFC/GWU) and
L. Vetere (PSU) report on behalf of the Swift Team:

At 19:58:09 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081008 (trigger=331093).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 279.987, -57.464 which is 
   RA(J2000) = 18h 39m 57s
   Dec(J2000) = -57d 27' 50"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a double-peaked
structure with a duration of about 150 sec.  The peak count rate
was ~2500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 19:59:36.5 UT, 87.1 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 279.9587, -57.4312 which is equivalent to:
   RA(J2000)  = 18h 39m 50.08s
   Dec(J2000) = -57d 25' 52.3"
with an uncertainty of 5.3 arcseconds (radius, 90% containment). This
location is 130 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy. 

UVOT took a finding chart exposure of 150 seconds with the White (160-650 nm)
filter starting 96 seconds after the BAT trigger. There is a candidate
afterglow in the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 18:39:50.11 = 279.9588
  DEC(J2000) = -57:25:52.3  = -57.4312
with a 1-sigma error radius of about 1.6 arc sec. This position is 0.3 arcseconds
from the center of the XRT error circle. The estimated magnitude is 15.0 with a
1-sigma error of about 0.5 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.10. 

Burst Advocate for this burst is J. L. Racusin (racusin AT astro.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081008A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8345
SUBJECT: GRB 081008: VLT/FORS2 spectroscopy
DATE:    08/10/09 03:32:02 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB), V. D'Elia (INAF-OAR), S. Covino (INAF-OAB) 
report, on behalf of the MISTICI collaboration:

Following the detection of GRB 081008 (Rykoff, GCN 8343; Racusin et al., 
GCN 8344), we triggered observations with the FORS2 camera, mounted at 
ESO-VLT. The observations were performed using the 600B grism. We took a 
900 s spectrum starting around Oct 09 at 00:20 UT (about 4.5 hours after 
the burst) and covering the range 380-620 nm.

The non-detection of Ly-alpha sets an upper limit of z ~ 2 to the GRB 
redshift. We detect a double horned absorption feature around lambda 
4600 A which we identify as the MgII doublet at 2796-2803 A. This 
implies a redshift of the absorber of z = 0.64. We also detect two 
absorption features around lambda 4530-4550 A which we identify as FeII 
2586 and FeII 2600 A. We possibly interpret this signature as another 
absorption system at z = 0.75.

However, at the present stage, the most robust redshift range that we 
can set for GRB 081008 is 0.64 < z < 2.

Further analysis is in progress.

We are very grateful for the excellent support of the VLT staff.


GRB_name: GRB081008A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8346
SUBJECT: GRB 081008: Gemini-South Absorption Redshiftt
DATE:    08/10/09 04:15:43 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara@astro.psu.edu>

A. Cucchiara, D. B. Fox (Penn State), S. B. Cenko  (Berkeley) and E. Berger
(Harvard) report on behalf of a larger collaboration:

Starting at 00:20 UT on 2008 October 9 (T0+5h) we observed the optical
counterpart of GRB 081008 (Racusin et al., GCN 8344, Rykoff  et al.,
GCN 83433) using Gemini-South with the GMOS-South spectrograph (R~1600).
We acquired 2x900s spectra covering the wavelength range 3800A-6700A.

We clearly detect several metal absorption features which we interpret as
SiIV(1393,1402), SiII1526, SiII*1816, CIV(1548,1550), FeII1608, AlII1670,
NiII1703, AlIII(1854,1862), MgI2026 at the common redshift of z = 1.967.

The absorption system identified by D'Avanzo et al. (GCN 8345) can be
explained by the CIV and SiII/SiII* doublets at this redshift.

We thank the Gemini staff for conducting these observations.


GRB_name: GRB081008A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8347
SUBJECT: GRB 081008: Enhanced Swift-XRT position
DATE:    08/10/09 06:03:32 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 8661 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 081008, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 279.95776, -57.43188 which is equivalent
to:

RA (J2000): 18h 39m 49.86s
Dec (J2000): -57d 25' 54.8"

with an uncertainty of 1.4 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081008A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8348
SUBJECT: GRB081008: Swift/UVOT observations
DATE:    08/10/09 10:30:54 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) and J. L. Racusin (PSU) report on behalf of the 
Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 081008 96 s 
after the BAT trigger (Racusin et al., GCN Circ. 8344), using a newly 
implemented observing sequence. The new sequence takes a 150s white-band 
finding chart exposure, followed by a 250s u-band exposure, after which 
the filter wheel rotates through all filters, taking short 20s exposures.

A new fading source is detected at the ROTSE position (Rykoff et al., GCN 
Circ 8343) in the white, v, b, u and uvw1 filters, consistent with a 
redshift of z=1.967 reported by Cucchiara et al., (GCN Circ 8346). The 
source is decaying at a constant rate of 0.90+/-0.03 for the duration of 
intial UVOT observations, out to ~700s after the BAT trigger. The UVOT 
refined position is
RA(J2000) = 18:39:49.877 (279.95833 deg)
Dec(J2000) = -57:25:52.87 (-57.431111 deg)
with an estimated uncertainty of 0.6 arcsec (radius, 90% confidence).

The detections and 3 sigma upper limits of the fading afterglow are 
reported below, where T_start and T_stop represent the elapsed time since 
the BAT trigger in seconds, and fc indicate finding chart exposures

Filter      T_start(s) T_stop Exp(s) Mag or 3 Sigma Limit
white (fc)   96  246 146 14.96 +/- 0.01
white534554 1915.87 +/- 0.03
u (fc)  254 504 24615.19 +/- 0.02
u    658 678 19  15.81 +/- 0.08
v    58460419 15.64 +/- 0.10
b 510 530 1915.79 +/- 0.05
uvw1    633  653 19 17.03 +/- 0.22
uvm2  608 1601117 > 19.16
uvw2    5591717 128> 19.53

The above magnitudes are not corrected for the Galactic extinction 
corresponding to a reddening of E(B-V) = 0.10 mag (Schlegel et al., 1998, 
ApJS, 500, 525). The photometry is on the UVOT photometric system 
described in Poole et al. (2008, MNRAS, 383,627).


GRB_name: GRB081008A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8349
SUBJECT: GRB 081008: Swift-XRT Refined Analysis
DATE:    08/10/09 14:55:07 GMT
FROM:    Judith Racusin at PSU  <racusin@astro.psu.edu>

J. L. Racusin (PSU) reports on behalf of the Swift-XRT team:

We have analyzed the first 7 orbits of XRT data for GRB 081008 (Racusin et 
al., GCN 8344), including 315 s of WT data and 6.9 ks of PC data.  The 
UVOT-enhanced position was given by Evans et al. (GCN 8347).  The 
results of the automatic analysis of the XRT data are available at 
http://www.swift.ac.uk/xrt_products.

The 0.3-10.0 keV lightcurve shows three bright flares superimposed on a 
steep decay, followed by a plateau with a decay index of 0.9 +/- 0.1, 
breaking at 16 +/- 14 ks to a decay index of 2.0 {+1.8,-0.9}.

The WT spectrum, for which changes in the hardness ratio during the flares 
suggests spectral evolution, can be fit by an absorbed power-law, with 
photon index = 1.81 +/- 0.03 and NH = (6.7 +/- 0.8)e21 cm^-2 at z = 1.967 
(Cucchiara et al., GCN 8346), in addition to the Galactic value of 7.1e20 
cm^-2. The observed (unabsorbed) flux over this time (93-408 s after the 
trigger) is 3.1e-9 (3.9e-9) erg cm^-2 s^-1.

The PC spectrum can be fit by an absorbed power-law, with photon index = 
1.91 +/- 0.07 and NH = (5.9 {+15.1, -5.9})e20 cm^-2 at z = 1.967, 
consistent with the Galactic value. The observed (unabsorbed) flux over 
this time (412 s - 11.9 ks after the trigger) is 3.4e-11 (4.0e-11) erg 
cm^-2 s^-1.

Assuming the X-ray emission continues to decline at the same rate, we 
predict a 0.3-10.0 keV XRT count rate of 3.6e-3 counts/s at T+24hr, which 
corresponds to an observed (unabsorbed) flux of 1.4e-13 (1.7e-13) ergs 
cm^-2 s^-1.

This Circular is an official product of the Swift-XRT team.


GRB_name: GRB081008A
Detection_method: Optical
Circular_text:
==> /universe/htdocs/docs/gamcosray/legr/bacodine/bin_web/tmp/new_gcn3_mesg <==
TITLE:   GCN CIRCULAR
NUMBER:  8350
SUBJECT: GRB 081008: VLT redshift confirmation 
DATE:    08/10/09 16:10:20 GMT
FROM:    Paolo D'Avanzo at INAF-OAB  <paolo.davanzo@brera.inaf.it>

P. D'Avanzo (INAF-OAB), V. D'Elia (INAF-OAR), S. Covino (INAF-OAB) 
report, on behalf of the MISTICI collaboration:

We observed the optical afterglow of GRB 081008 (Rykoff, GCN 8343; 
Racusin et al., GCN 8344), with the ESO VLT on Oct 09 starting about 4.5 
hours after the burst with UVES. In the UVES spectrum  we clearly detect 
the Ly-alpha around lambda 3600 A at a redshift z = 1.96, further 
analysis of this spectrum are ongoing. In light of this, from a refined 
analysis of our VLT/FORS2 spectrum of this GRB (D'Avanzo et al. GCN 
8345), we can identify the metal lines reported by Cucchiara et al. (GCN 
8346) and the absorption lines CrII(2056, 2062,2066) and ZnII(2062) all 
at a redshift z = 1.9685.

Our results are thus in agreement with what reported by Cucchiara et al.


GRB_name: GRB081008A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8351
SUBJECT: GRB 081008, Swift-BAT refined analysis
DATE:    08/10/09 19:50:57 GMT
FROM:    Wayne Baumgartner at GSFC  <wayne@milkyway.gsfc.nasa.gov>

GRB 081008, Swift-BAT refined analysis

D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner
(GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt
(GSFC/UMD), K. McLean (GSFC/UMD), A. M. Parsons (GSFC), J. L. Racusin
(PSU), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos
(GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU); (i.e. the
Swift-BAT team):

Using the data set from T-240 to T+963 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 081008 (trigger
#331093) (Racusin et al., GCN Circ. 8344).  The BAT ground-calculated
position is RA, Dec = 279.968, -57.433 deg which is
    RA(J2000)  =  18h 39m 52.4s
    Dec(J2000) = -57d 25' 58.8"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90%
containment).  The partial coding was 81%.

The mask-weighted lightcurve shows two strong peaks at T+0 and T+110s.
T90 (15-350 keV) is 185.5 +- 40.3 sec (estimated error including
systematics).

The time-averaged spectrum from T-65 to T+201 sec is best fit by a
simple power-law model.  A cutoff-power law model is also an
acceptable fit with an E_peak of 88 keV.  The power law index of the
time-averaged spectrum is 1.69 +- 0.07.  The fluence in the 15-150 keV
band is 4.3 +- 0.2 x 10^-06 erg/cm2.  The 1-sec peak photon flux
measured from T+7.52 sec in the 15-150 keV band is 1.3 +- 0.1
ph/cm2/sec.  All the quoted errors are at the 90% confidence level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/331093/BA/


GRB_name: GRB081007A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8352
SUBJECT: GRB 081007: Rapid PROMPT Detections
DATE:    08/10/10 02:57:35 GMT
FROM:    James Philip West at UNC.Chapel Hill  <jpwest@uncg.edu>

J. P. West, M. Schubel, J. Haislip, R. Holmes, D. Reichart, M. Nysewander,
A. LaCluyze, K. Ivarsen, J. A. Crain, A. Foster, T. Brennan, R. Rhine, J.
Styblova, A. Trotter, and E. Weaver report:

Skynet observed the localization of GRB 081007 (Baumgartner et al., GCN
8330) with four of the 16" PROMPT telescopes at CTIO beginning 41 seconds
after the trigger (24 seconds after notification) in UBVRI.

We detect the afterglow (Baumgartner et al., GCN 8330) in BVRI.  At 121
seconds after the burst, we measure I ~ 14.8 mag (calibrated to 6 USNO B1
stars).


GRB_name: GRB081001A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8353
SUBJECT: Konus-Wind observation of GRB 081001
DATE:    08/10/10 14:05:56 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin,
D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov
and T. Cline, on behalf of the Konus-Wind team report:

The GRB 081001 localized by SuperAGILE
(Lazzarotto et al., GCN 8305) triggered Konus-Wind
at T0=76663.649 s UT (21:17:43.649).

The burst light curve shows a main pulse with a duration of ~6 s 
followed by a much weaker pulse at T0+~30 s with a duration of ~10 s.

As observed by Konus-Wind the burst
had a fluence of 9.70(-0.86, +1.00)x10^-6 erg/cm2,
and a 64-ms peak flux measured from T0+0.688 s
of 5.63(-1.12, +1.16)x10^-6 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The spectrum of the main pulse
(from T0 to T0+8.448 s) is well fitted (in the 20 keV-2 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.99(-0.18, +0.21),
and Ep = 239(-32, +45) keV (chi2 = 54.9/61 dof).
Fitting by GRBM (Band) model yields:
the low-energy photon index is alpha = -0.95(-0.21, +0.48),
the high energy photon index beta < -2.14,
the peak energy Ep = 227(-70, +52) keV (chi2 = 54.1/60 dof).
All the quoted errors are at the 90% confidence level.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB081001_T76663/


GRB_name: GRB081007A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8354
SUBJECT: GRB 081007: Radio Detection
DATE:    08/10/10 14:09:18 GMT
FROM:    Alicia Soderberg at Caltech  <ams@astro.caltech.edu>

Alicia Soderberg (Harvard/SAO) and Dale Frail (NRAO) report on behalf of 
a larger collaboration:

"We observed the field of GRB 081007 (GCN 8330) with the Very Large Array 
beginning at Oct 9.19 UT.  At 8.46 GHz we detect a radio source 
coincident with the optical afterglow position at coordinates (J2000):

RA =  22 39 50.3882   +/-  0.0009
Dec = -40 08 49.18    +/-  0.03

with flux density 0.32 +- 0.03 mJy.  Further observations are scheduled.

The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc."


GRB_name: GRB081011A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8355
SUBJECT: GRB 081011: Swift detection of a burst
DATE:    08/10/11 00:57:02 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

D. Grupe (PSU), A. P. Beardmore (U Leicester),
P. A. Evans (U Leicester), S. T. Holland (CRESST/USRA/GSFC),
E. A. Hoversten (PSU), J. A. Kennea (PSU),
C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), J. L. Racusin (PSU), M. Stamatikos (NASA/ORAU),
M. C. Stroh (PSU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU)
report on behalf of the Swift Team:

At 00:28:50 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081011 (trigger=331332).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 220.361, +33.607 which is 
   RA(J2000) = 14h 41m 27s
   Dec(J2000) = +33d 36' 27"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single complex peak
structure with a duration of about 15 sec.  The peak count rate
was ~1100 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 00:30:24.4 UT, 93.9 seconds after
the BAT trigger. No source was detected in the promptly available XRT
data. This is highly unusual for a long GRB  
with a prompt Swift slew.  We are waiting for the full dataset 
to detect and localise the XRT counterpart. 


UVOT took a finding chart exposure of 150 seconds with the White (160-650 nm)
filter starting 98 seconds after the BAT trigger. No afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of
the BAT error circle. The typical 3-sigma upper limit has been about 18.5 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
BAT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.01. 




Burst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081008A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8356
SUBJECT: GRB 081008, SMARTS optical/IR afterglow observations
DATE:    08/10/11 01:29:39 GMT
FROM:    Bethany Cobb at UC Berkeley  <bcobb@astro.berkeley.edu>

B. E. Cobb (UC Berkeley) reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 081008
(GCN 8344, Racusin et al.).  Several dithered images were obtained
in each filter, with total summed exposure times of 180s in each
of BRIJK and 120s in each of H and V.

At a mid-exposure time of 2008-10-08 23:53 (3.9 hrs post-burst),
the GRB afterglow (GCN 8343, Rykoff et al. and GCN 8344, Racusin et al.)
is detected with the following magnitudes:
B = 19.86 +/- 0.07
R = 18.46 +/- 0.04
I = 18.09 +/- 0.05
J = 17.13 +/- 0.10
H = 16.52 +/- 0.08
K = 16.08 +/- 0.09

Observations were obtained under non-photometric conditions.  In optical, 
these
preliminary magnitudes are calibrated against several USNO-B1.0 stars in
the field, so there is likely an additional photometric calibration error
of ~0.2 magnitudes.  In the IR, calibration is against 2MASS stars.

Additional observations were obtained at 5.0 hrs and 6.4 hrs post-burst.
Between 3.9 hrs and 6.4 hours post-burst, the afterglow decays
rapidly with an approximate optical decay rate of alpha~-1.5 (where 
afterglow flux is proportional to t^alpha).

[GCN OPS NOTE(27oct08): Per author's request, the errors for the J,H,K
measurements from 0.97,0.77,0.90 to 0.10,0.08,0.09, respectively.]


GRB_name: GRB081011A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8357
SUBJECT: GRB 081011, Swift-BAT refined analysis
DATE:    08/10/11 13:38:06 GMT
FROM:    Takanori Sakamoto at NASA/GSFC  <takanori.sakamoto-1@nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC),W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
D. M. Palmer (LANL), A. M. Parsons (GSFC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 081011 (trigger #331332)
(Grupe, et al., GCN Circ. 8355).  The BAT ground-calculated position is
RA, Dec = 220.363, 33.548 deg which is 
   RA(J2000)  =  14h 41m 27.2s 
   Dec(J2000) = +33d 32' 54.4" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows two peaks around T+2 and T+9 sec.  
There is a hint of a weak extended emission until T+60 sec.  
T90 (15-350 keV) is 9 +- 2 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.9 to T+9.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.47 +- 0.28.  The fluence in the 15-150 keV band is 1.6 +- 0.3 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+1.06 sec in the 15-150 keV band
is 0.4 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/331332/BA/


GRB_name: GRB081011A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8358
SUBJECT: GRB 081011: Swift/XRT detection
DATE:    08/10/11 14:38:39 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

J. A. Kennea and D. Grupe (PSU) report on behalf of the Swift/XRT Team

We have analyzed downlinked data from the XRT observations of GRB 081011 
(Grupe et al, GCN #8355). The XRT began observing the field at 00:30:24.4 
UT, 94 seconds after the BAT trigger. Data from the first orbit of 
observations reveal an uncatalogued fading point source at RA, Dec = 
220.34435, +33.544771 which is the equivalent to:

RA(J2000) = 14h 41m 22.6s
Dec(J2000) = +33d 32m 41.1s

with an estimated uncertainty of 8 arcseconds radius (90% confidence). 
This position is 57 arcseconds from the BAT refined position (Sakamoto et 
al, GCN #8357).


GRB_name: GRB081011A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8359
SUBJECT: GRB081011: UVOT detection of an optical afterglow
DATE:    08/10/11 17:57:02 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) and D.Grupe (PSU) report on behalf of the Swift/UVOT 
team:

The Swift/UVOT observed the field of GRB 081011 (Grupe et al., GCN Circ. 
8355) with settled exposures starting 99s after the trigger. A new fading 
source is detected in the white and u-band finding chart (fc) exposures 
and marginally in a co-added b-band exposure at
RA(J2000) = 14:41:22.627 (220.34428)
Dec(J2000) = +33:32:37.12 (+33.54364)
consistent with the XRT position (Kennea et al., GCN Circ. 8358). These 
detections imply an upper limit on the redshift of z < ~3.8. The source is 
decaying with an approximate optical decay rate of alpha~1.1 (where the 
afterglow flux is proportional to t^-alpha).

The detections and 3 sigma upper limits in the UVOT photometric system 
(Poole et al. 2008, MNRAS, 383, 627) are:

Filter      T_start T_stop  Exp     Mag or 3-sigma UL
            (s)     (s)     (s)
========================================================
white (FC)  99      249     145.8   19.25 +/- 0.08
white       537     1878    283.5   20.33 +/- 0.13
u (FC)      257     507     245.8   18.62 +/- 0.10
u           660     2003    155.6   19.91 +/- 0.30
v           586     7371    548.8   > 20.29
b           512     6756    351.4   21.13 +/- 0.39
uvw1        636     7781    548.8   > 20.96
uvm2        611     7576    548.9   > 20.74
uvw2        562     7167    548.8   > 21.06

The values quoted above are not corrected for the expected Galactic 
extinction corresponding to a reddening of E(B-V) = 0.01 mag in the 
direction of the burst (Schlegel et al. 1998).


GRB_name: GRB081011A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8360
SUBJECT: Revised table for GRB 081011 UVOT detections
DATE:    08/10/11 18:08:10 GMT
FROM:    Patricia Schady at MSSL/Swift  <ps@mssl.ucl.ac.uk>

P. Schady (MSSL-UCL) report on behalf of the Swift/UVOT team:

Due to formatting problems, the data table in GCN Circ 8359 (Schady et 
al.) is unreadable. Below is the properly formatted version of the UVOT 
data table for GRB 0810111

Filter     T_start T_stop  Exp    Mag or 3-sigma UL
            (s)     (s)     (s)
===================================================-
white (FC)  99      249    145.8  19.25 +/- 0.08
white       537     1878   283.5  20.33 +/- 0.13
u (FC)      257     507    245.8  18.62 +/- 0.10
u           660     2003   155.6  19.91 +/- 0.30
v           586     7371   548.8  > 20.29
b           512     6756   351.4  21.13 +/- 0.39
uvw1        636     7781   548.8  > 20.96
uvm2        611     7576   548.9  > 20.74
uvw2        562     7167   548.8  > 21.06

The values quoted above are not corrected for the expected Galactic 
extinction corresponding to a reddening of E(B-V) = 0.01 mag in the 
direction of the burst (Schlegel et al. 1998).


GRB_name: GRB081012A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8361
SUBJECT: GRB 081012: Swift detection of a burst
DATE:    08/10/12 13:19:01 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

M. C. Stroh (PSU), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
P. A. Evans (U Leicester), D. Grupe (PSU),
S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU),
J. A. Kennea (PSU), D. M. Palmer (LANL), D. Perez (U Leicester),
J. L. Racusin (PSU), T. Sakamoto (NASA/UMBC),
T. N. Ukwatta (GSFC/GWU), L. Vetere (PSU) and H. Ziaeepour (UCL-MSSL)
report on behalf of the Swift Team:

At 13:10:23 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081012 (trigger=331475).  Swift did not immediately slew due to
the Earth limb constraint.  The BAT on-board calculated location is 
RA, Dec 30.217, -17.641 which is 
   RA(J2000) = 02h 00m 52s
   Dec(J2000) = -17d 38' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 20 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to an observing constraint, Swift will not slew until 
T0+49.2 minutes. There will be no XRT or UVOT data until
this time. 

Burst Advocate for this burst is M. C. Stroh (stroh AT astroh.org). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


GRB_name: GRB081012A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8362
SUBJECT: GRB 081012: ROTSE-III Optical Limits
DATE:    08/10/12 14:54:25 GMT
FROM:    Fang Yuan at ROTSE  <yuanfang@umich.edu>

F. Yuan (U Mich) report on behalf of the ROTSE collaboration:

ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded  
to GRB 081012 (Swift trigger 331475, GCN 8361, Stroh et al. ),  
producing images beginning 7.2s after the GCN notice time. An  
automated response took the first image at 13:11:03.2 UT, 39.3s after  
the burst. Early observations were affected by proximity to the full  
moon and the first usable image started at 13:27:03.0 UT, ~1000s after  
the burst. We took over 100 20s exposures. These unfiltered images are  
calibrated relative to USNO A2.0 (R). Imaging is on going.

Comparison to the DSS (second epoch) reveals no new sources within the  
3-sigma Swift/BAT error circle, for both single images and coadding  
into sets of 10. Individual images have limiting magnitudes ranging  
from 15.8-16.2; we set the following specific limits.

start UT       end UT      t_exp(s)   mlim   t_start-tGRB(s)  Coadd?
--------------------------------------------------------------------
13:27:03.0   13:27:23.0        20     15.8             999       N
13:28:01.3   13:32:42.9       281     17.4          1057       Y


GRB_name: GRB081012A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8363
SUBJECT: GRB 081012, Swift-BAT refined analysis
DATE:    08/10/12 16:34:59 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

G. Sato (ISAS), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL),
T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), M. C. Stroh (PSU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-119 to T+183 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 081012 (trigger #331475)
(Stroh, et al., GCN Circ. 8361).  The BAT ground-calculated position is
RA, Dec = 30.184, -17.627 deg which is 
   RA(J2000)  =  02h 00m 44.1s 
   Dec(J2000) = -17d 37' 36.2" 
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.
 
The mask-weighted light curve shows a roughly symmetrical peak starting 
at ~T-20 sec, peaking at ~T+1 sec, and ending at ~T+20 sec.  There is
a possibility of earlier emission at ~T-50 sec.
T90 (15-350 keV) is 29 +- 4 sec (estimated error including systematics).
 
The time-averaged spectrum from T-23.1 to T+8.9 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.03 +- 0.18.  The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.93 sec in the 15-150 keV band
is 1.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/331475/BA/


GRB_name: GRB081012A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8364
SUBJECT: GRB 081012: Swift/XRT detection
DATE:    08/10/12 17:06:28 GMT
FROM:    Jamie A. Kennea at PSU/Swift-XRT  <kennea@astro.psu.edu>

J. A. Kennea and M. Stroh (PSU) report on behalf of the Swift/XRT Team

We have analyzed downlinked data from the XRT observations of GRB 081012
(Stroh et al, GCN #8361). The XRT began observing the field at 14:00:09 
UT, approximately 49 minutes after the BAT trigger. Data from the first 
orbit of observations reveal an uncatalogued point source at RA, Dec = 
30.20029, -17.63715 which is the equivalent to:

RA(J2000) = 02h 00m 48.0s
Dec(J2000) = -17d 38m 13.7s

with an estimated uncertainty of 8 arcseconds radius (90% confidence). 
This position is 67 arcseconds from the BAT refined position (Sato et 
al, GCN #8363).


GRB_name: GRB081012A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8365
SUBJECT: GRB 081012: Swift/UVOT analysis of initial observations
DATE:    08/10/12 20:33:06 GMT
FROM:    Paul Kuin at MSSL  <npkuin@googlemail.com>

N. P. M. Kuin (MSSL/UCL) and M.C. Stroh (PSU) report on behalf of
the Swift UVOT team.

The Swift UltraViolet/Optical Telescope (UVOT) began observations of
GRB081012 (Swift BAT trigger number 331475, Stroh et al., GCN Circ.
8361), on October 12, 2008, at 14:02:28 ,52 minutes after the
trigger.

We do not detect any new source at the XRT position reported in GCN
Circ. 8364 (Kennea et al.).

The magnitude upper limits for detecting GRB081012 at the XTR position
are given below for the first observations in the UVOT filters:

Filter Tstart(s) Tstop(s)  Exp(s)  Magnitude

uvw2   3125      3325     196.6    >20.09  (3-sigma UL)
v      3329      3458     125.8    >19.12  (3-sigma UL)
uvm2   4876      5076     196.6    >19.72  (3-sigma UL)
uvw1   5082      5282     196.6    >19.94  (3-sigma UL)
u      5287      5487     196.6    >20.00  (3-sigma UL)
b      5492      5692     196.6    >20.33  (3-sigma UL)
wh     5697      5713      15.7    >19.42  (3-sigma UL)

The values quoted above are on the UVOT Photometric System
(Poole et al, 2008, MNRAS 383,627). They are not corrected for the
expected galactic reddening of E(B-V) = 0.023 in the direction of
the burst (Schlegel et al. 1998).


GRB_name: GRB081012A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8366
SUBJECT: GRB 081012: Observations from NOT
DATE:    08/10/13 01:25:26 GMT
FROM:    Antonio Deugarte at IAA-CSIC  <deugarte@iaa.es>

A. de Ugarte Postigo (ESO), D. Malesani (DARK/NBI)
T. Augusteijn (NOT) report on behalf of a larger
collaboration:

We have observed the field of GRB 081012 (Stroh et al.,
GCN 8361) from the 2.5m NOT telescope at Roque de los
Muchachos Observatory. A combination of 6x300s R-band
observations with mean time 23.79 UT (0.44 days after
the burst) did not show any source within the XRT error
box (Kennea & Stroh GCN 8364) down to a 3-sigma
limiting magnitude of R > 22.0. The images were moderately
contaminated by the light of the nearby Moon.

We thank the student group from the Mikkeli high school (Finland)
for help in carrying out the observations.

[GCN OPS NOTE(13oct08): Per author's request, the last paragraph
was added.]


GRB_name: GRB081008A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8367
SUBJECT: GRB 081008 optical upper limit
DATE:    08/10/13 12:04:46 GMT
FROM:    AAVSO GRB Network at AAVSO  <matthewt@aavso.org>

Peter Nelson (Ellinbank, Victoria, Australia) reports to the AAVSO 
International High Energy Network the following optical observation of 
GRB081008 (GCN #8344 Racusin et al.; GCN #8343 Rykoff et al.):

Peter Nelson has obtained a limiting magnitude on the optical afterglow of 
GRB081008 (Racusin et al., GCN #8344).  The optical afterglow position RA: 
18:39:50, Dec: -57:25:52 found by Rykoff et al. (GCN #8343) was observed 
for a total of 480 seconds using a 0.32-meter Newtonian with an SBIG ST8XE 
CCD and an R filter.  The mid-point of the observations was 2008 Oct 
09.4150 UT, approximately 14 hours after the burst.  The afterglow was not 
detected to an upper limit of R=18.2, using USNO-A2.0 star 0300-34687382 
(R=11.8) as the comparison.  This upper limit is consistent with the 
R-band magnitude of R=18.46 on 2008 Oct 08.9951 observed by Cobb et al. 
(GCN #8356).

A detailed report of these observations is available on the AAVSO website 
at ftp://ftp.aavso.org/grb/PeterNelson_081008_2454752.03073_.txt

A fits image is available at
ftp://ftp.aavso.org/grb/PeterNelson_081008_2454752.03073_.fits

The AAVSO thanks the Curry Foundation for their continued support of the 
AAVSO International High Energy Network.


GRB_name: GRB080430A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8368
SUBJECT: GRB 080430: optical observations 
DATE:    08/10/13 15:39:36 GMT
FROM:    Graziella Pizzichini at IASF/CNR,Bologna  <pizzichini@iasfbo.inaf.it>

    F. Terra (Second University of Roma "Tor Vergata"),  F. Munz (INAF/IASF
    Bologna) G. Greco, C. Bartolini, A. Guarnieri,A. Piccioni (Bologna
    University), D. Nanni (INAF/OAR and Second University of Rome "Tor
    Vergata"), G. Pizzichini(INAF/IASF Bologna),  S. Galetti and S. Bernabei
    (Bologna Observatory) report:

    During the night between 08/04/30 and 080501 we observed the OT of
    GRB080430 (Guidorzi et al., GCN 7647, Klotz, Boer & Atteia, GCN 7646)
    in Rc, V, B AND I  with the 1.52  cm telescope of the Bologna Observatory
    in Loiano in good weather conditons, airmass  between 1 and 1.6,
    seeing less than 4".
    Calibration was obtained from the NOMAD catalog in the Rc filter and from
    the SDSS observations by Cool et al. in GCN 7649 for the other filters.
    We obtain the following magnitudes
    obs midpoint      duration filter mag   error
                       seconds
    2454587.40325        600     Rc  19,47  0,11
    2454587.41120        600     V   19,20  0.12
    2454587.42067        600     Rc  19,75  0,11
    2454587.43274       1200     B   19,54  0,12
    2454587.44788        600     Rc  19,60  0,15
    2454587.45720        600     I   19,03  0,05
    2454587.46673        600     Rc  19,75  0,11
    2454587.47927        600     V   19,44  0,12
    2454587.48806        600     Rc  19,96  0,10
    2454587.51098        600     Rc  20,28  0,09
    2454587.52303        600     Rc  20,01  0,09
    2454587.53175        600     Rc  20,27  0,15
    2454587.53946        600     I   19,14  0,06
    2454587.54819        600     Rc  20,53  0,10

    Our  images have been posted in our public directory
    from where they can be retrieved by sftp using
    hostname: ermione.bo.astro.it
    username: publicGRB
    password: GRB_bo
    directory: /home/publicGRB/GRB080430/


GRB_name: GRB081007A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8369
SUBJECT: GRB 081007 and GRB 081007B: Fermi GBM detection
DATE:    08/10/13 18:18:15 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi, S. McBreen (MPE) and V. Connaughton (UAH) 
report on behalf of the Fermi GBM Team: 


"At 05:21:51 UT on 7 October 2008, the Fermi Gamma-ray Burst Monitor
triggered on a very weak burst GRB 081007B (trigger 245049712/081007224).
The duration of this event is about 0.5 s but due to the lack of counts 
it was not possible to accurately localize it or perform spectral 
analysis. 

121 seconds later, at 05:23:52 UT, Swift/BAT triggered on GRB 081007
(Baumgartner et al., GCN 8330). This event was also detected 
by GBM. The angle from the Fermi LAT boresight to the Swift position 
is 116 degrees. Based on the detector geometry GRB081007 does
not appear to be related to GRB 081007B.

GRB 081007 is single peaked with an estimated T90 (25-900 keV) 
of about 12 s. The time-averaged spectrum from T0+0.6 s to T0+6.8 s 
relative to the Swift trigger is adequately fit by a power law with 
an index of -2.1 +/- 0.1, in agreement with the Swift-BAT refined 
analysis (Markwardt et al., GCN 8338). It can also be fit 
with a power law function with an exponential high energy cutoff.  
The cutoff energy, parameterized as Epeak, is 40 +/- 10 keV.
In this case the power law index is poorly constrained (-1.4 +/- 0.4).

The fluence (25-900 keV) for the power law model is  
(1.2 +/- 0.1)E-06 erg/cm2. 
The 1 sec peak photon flux measured starting from T0+0.9 in 
the 25-900 keV band is 2.2 +/- 0.2 ph/s/cm2.


The spectral analysis results presented above are preliminary;
the final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB081012A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8370
SUBJECT: GRB 081012: Fermi GBM detection
DATE:    08/10/13 18:21:10 GMT
FROM:    Elisabetta Bissaldi at MPE  <ebs@mpe.mpg.de>

E. Bissaldi (MPE) reports on behalf of the Fermi GBM Team: 


"At 13:10:23 UT on 12 October 2008, the Fermi Gamma-ray Burst Monitor
triggered and located GRB 081012 (trigger 245509824/081012549), which
was also detected by Swift (Stroh et al., GCN 8361).
The on-ground calculated location, using the Fermi GBM trigger data, is 
RA = 30.9, Dec = -19.2 (equivalent to J2000 
02h 04m, -19d 12'), with a statistical uncertainty of 6.8 degrees 
(radius, 1-sigma containment; there is additionally a systematic 
error which is currently estimated to be 2 to 3 degrees). 
This position is 1.7 deg from the Swift XRT position
(Kennea et al., GCN 8364). The angle from the Fermi LAT boresight 
to the Swift position is 61 degrees.

GRB 081012 is single peaked with an estimated T90 (25-900 keV) 
of about 30 s. The time-averaged spectrum from T0-3.1 s to T0+7.2 s 
is well fit by a power law function with an exponential 
high-energy cutoff.  The cutoff energy, parameterized as
Epeak, is 360 +/- 70 keV with a power law index of -0.31 +/- 0.23.
It can also be fit by using a Band function with Epeak = 320 +/- 80 keV
and beta = -2.4 +/- 0.7. However alpha is poorly constrained.

The fluence (25-900 keV) for the power law model with
exponential cutoff is (3.8 +/- 0.4)E-06 erg/cm2. 
The 1 sec peak photon flux measured starting from T0+4.1 in 
the 25-900 keV band is 2.0 +/- 0.2 ph/s/cm2.


The spectral analysis results presented above are preliminary;
the final results will be published in the Fermi GBM GRB Catalog."


GRB_name: GRB081008A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8372
SUBJECT: GRB 081008: Galaxy associated with z=1.967 absorber
DATE:    08/10/14 00:17:32 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara@astro.psu.edu>

A. Cucchiara, D. B. Fox (Penn State), S. B. Cenko  (Berkeley) and E. Berger
(Harvard) report on behalf of a larger collaboration:

"Analysis of the Gemini-South GMOS r-band acquisition image taken on 
October 8
(Cucchiara et al., 8346) shows the presence of an extended source at 
2-arcsec
distance from the afterglow of GRB 081008.  The source is serendipitously
located in the GMOS slit during our spectroscopic observations.

Extracting the spectrum of this object reveals the presence of metal 
absorption
features including FeII(1608), AlII(1670), NiII(1703), AlIII(1854), and
CrII(2056,2062,2066) at a common redshift z=1.967.  We conclude that this
galaxy is associated with the strong z=1.967 absorber observed in the GRB
afterglow spectrum, and is a candidate host galaxy to the GRB.

The galaxy is located at (J2000) RA 18:39:49.64, Dec -57:25:53.41.  At 
z=1.967
its 2.1-arcsec offset from the line of sight to GRB 081008 corresponds 
to 16 kpc
in projection.

We report the R-band magnitude of the GRB and the Host, calibrated using 
USNO
catalog magnitudes of 4 nearby USNO stars:  At the time of the 
acquisition image,
00:01 UT, we find R=18.32 +- 0.1 mag for the GRB afterglow, and R=20.75 
+- 0.1
mag for the galaxy.

The observed host galaxy magnitude corresponds to an absolute AB 
magnitude (at
central wavelength 220 nm in the host galaxy frame) of M_220(AB) = -21.5 
mag;
assuming a comparable rest-frame B-band luminosity would place this galaxy
among the brightest GRB host galaxies if it is the host galaxy of GRB 081008
(Berger et al., Apj 2007, 657).

While we cannot confirm a host identification at this time, we note that the
presence of an associated DLA in the VLT/FORS2 spectrum (d'Avanzo et al.,
GCN 8350), along with the reported absence of any absorption signature due
to neutral hydrogen at z>1.967, both support this suggestion."


-- 

Antonino Cucchiara
PhD candidate
Department of Astronomy&Astrophysics
Penn State University
website: www.astro.psu.edu/~cucchiara/


GRB_name: GRB081012A
Detection_method: GROND
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8373
SUBJECT: GRB 081012: GROND upper limits
DATE:    08/10/14 09:44:50 GMT
FROM:    Robert Filgas at MPI  <filgas@mpe.mpg.de>

R. Filgas, T. Kruehler, J. Greiner, C. Clemens, A. Yoldas (all MPE
Garching), A. Rossi (Tautenburg Obs.), A. Kupcu Yoldas (ESO) and
G. Szokoly (Eoetvoes Univ., Budapest) report on behalf of the GROND team:

GROND (Greiner et al. 2008, PASP 120, 405), mounted at the 2.2m
ESO/MPI telescope at La Silla Observatory (Chile), started
observations of the field of GRB 081012 (Stroh et al. 2008, GCN #8361)
in g'r'i'z'JHK at 07:43 UT on 13. Oct. 2008, 18.5 hours after
the burst. This burst was also detected by the Fermi GBM (Bissaldi
2008, GCN #8370). GROND observations consisted of 20 115-s
integrations in g'r'i'z' and 240 10-s integrations in JHK.

We do not detect a source in the XRT error circle (Kennea & Stroh
2008, GCN #8364) in the stacked images down to limiting magnitudes
(all in Vega system) of

g' > 23.2
r' > 23.5
i' > 22.8
z' > 22.8
J > 21.5
H > 20.4
K > 19.4

The given limits are derived based on calibrating the images
against USNO and 2MASS field stars and are not corrected for the Galactic
foreground extinction corresponding to a reddening of E_(B-V)= 0.023
in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB081009A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8374
SUBJECT: GRB 081009: Fermi GBM detection 
DATE:    08/10/14 16:15:25 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

A. von Kienlin (MPE), P.N. Bhat (UAH) and C.A. Wilson-Hodge (MSFC) 
report on behalf of the Fermi GBM Team: 

"At 03:20:58 UT on 9 October 2008, the Fermi GBM triggered 
and located GRB 081009 (trigger 245215259 / 081009140). 
The on-ground calculated location, using the GBM trigger 
data, is RA = 251.1, Dec = +17.1  (J2000 degrees, 
equivalent to 16h 44m, +17d 06'), with an uncertainty 
of 1.0 degree (radius, 1-sigma containment, 
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees). 
The angle from the Fermi LAT boresight is 67 degrees.

This GRB has two isolated peaks: 

The first peak is about 9 sec long. The time-averaged 
spectrum (8-1000 keV) from T0-0.1 s to T0+7.9 s is 
best fit by a Band function with Epeak = 47.4+/-0.3 keV, 
alpha = 0.10+/-0.03, and beta = -3.42+/-0.04. 
The fluence (8-1000 keV) is (3.5+/-0.1)E-05 erg/cm^2. 
The quoted errors are statistical only, the true errors are 
significantly larger due to systematic effects around the 
Iodine K-edge energy (33.2 keV) for this very strong event.

The second peak is about 13 sec long. The time-averaged 
spectrum (8-1000 keV) from T0+37.4 s to T0+49.3 s is 
best fit by a Band function with Epeak = 20.7+/-0.2 keV, 
alpha = 0.2+/-0.1, and beta = -4.0+/-0.1. 
The fluence (8-1000 keV) is (8.3+/-1.3)E-06 erg/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog."


GRB_name: GRB081016A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8377
SUBJECT: GRB 081016: A long GRB discovered by INTEGRAL
DATE:    08/10/16 08:18:04 GMT
FROM:    Sandro Mereghetti at IASF/CNR  <sandro@iasf-milano.inaf.it>

D.Gotz (CEA-Saclay), S.Mereghetti, A.Paizis (IASF-Milano), S. Soldi, 
V.Beckmann, M. Beck, M. Tuerler (ISDC, Versoix), and J. Borkowski (CAMK, 
Torun) on behalf of the IBAS Localization Team report:

A GRB lasting about 34 s has been detected by IBAS in IBIS/ISGRI data at 
06:51:31 UT of October 16. 

The coordinates (J2000) are:

RA = 255.5725 [degrees]
DEC= -23.3301 [degrees]

with an uncertainty of 1.5 arcmin (90% c.l.).

The burst is composed by two distinct peaks, and a preliminary spectral 
analysis gives a peak flux in the 20-200 keV range of about 2.4 
ph/cmsq/s (1-s integration time) and a fluence over the same energy range 
of about 1.8x10e-6 erg/cmsq. Due to data gaps caused by telemetry 
saturation these values should be considered as lower limits.

A plot of the light curve will be posted at

http://ibas.iasf-milano.inaf.it/IBAS_Results.html

This message can be cited.


GRB_name: GRB081016A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8379
SUBJECT: GRB 081016: Swift-XRT candidate afterglow detection
DATE:    08/10/16 17:19:15 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT Team

We have obtained 2 ks of XRT Photon Counting mode data of GRB 081016 (Gotz 
et al. GCN Circ. 8377), beginning 20.4 ks after the INTEGRAL trigger. We 
find an uncatalogued X-ray source at RA,Dec, 255.57032, -23.33556 which is 
equvialent to:

RA (J2000):  17 02 16.88
Dec (J2000): -23:20:08.0

with an estimated uncertainty of 3.6" (radius, 90% confidence). This 
position is 21" from the INTEGRAL position, within the INTEGRAL error 
circle. It is not currently possible to determine whether this source is 
fading. Further observations are planned.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB081011A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8380
SUBJECT: GRB 081011: Enhanced Swift-XRT position
DATE:    08/10/16 17:19:43 GMT
FROM:    Phil Evans at U of Leicester  <pae9@star.le.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 12236 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 081011, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 220.34404, +33.54332 which is equivalent
to:

RA (J2000): 14h 41m 22.57s
Dec (J2000): +33d 32' 35.9"

with an uncertainty of 1.5 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest position
can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is
described by Goad et al. (2007, A&A, 476, 1401
http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an
extension of this method.

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB081016B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  8381
SUBJECT: GRB 081016B: Swift detection of a burst
DATE:    08/10/16 20:04:12 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

K. L. Page (U Leicester), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), P. A. Evans (U Leicester),
O. Godet (U Leicester), C. Guidorzi (INAF-OAB),
S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),
W.B Landsman (GSFC), C. B. Markwardt (CRESST/GSFC/UMD),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
J. P. Osborne (U Leicester), D. M. Palmer (LANL),
M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester),
M. C. Stroh (PSU), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU)
report on behalf of the Swift Team:

At 19:47:14 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 081016B (trigger=331856).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 14.615, -43.543 which is 
   RA(J2000)  =  00h 58m 28s
   Dec(J2000) = -43d 32' 34"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single peak
with a duration of about 5 sec.  The peak count rate
was ~1600 counts/sec (15-350 keV), at ~2 sec after the trigger. 

The XRT began observing the field at 19:48:45.1 UT, 90.6 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued, 
fading X-ray source located at RA, Dec 14.5670, -43.5296 which is equivalent
to:
   RA(J2000)  = 00h 58m 16.08s
   Dec(J2000) = -43d 31' 46.6"
with an uncertainty of 3.3 arcseconds (radius, 90% containment). This
location is 134 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of
1.96e+20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White (160-650 nm)
filter starting 93 seconds after the BAT trigger. No afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.01. 

Burst Advocate for this burst is K. L. Page (kpa AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)


