- GCN Circular #7242
A. Copete, J. Grindlay, B. Allen, J. Hong (Harvard)
S. Barthelmy, C. Markwardt, N. Gehrels (GSFC)
We report the detection by the BAT Slew Survey (BATSS) of a burst in
the slew that started at 11:13:02 UT, at the position:
RA (J2000): 17h 26m 42s
Dec(J2000): -53d 11' 20"
with an uncertainty of 2.6 arcmin (90% confidence). This position is
the weighted average of independent 8.7 sigma and 7.6 sigma detections
made in the 15-50keV and 50-150keV energy bands, respectively.
Preliminary lightcurve analysis shows a main peak in both energy bands
at T+8sec (223384448s MET).
BATSS pipeline processing is in the final stages of development
following our first preliminary tests, which discovered GRB070326
(GCN# 6653). Full BATSS results will begin to be available soon from a
website to be announced.
- GCN Circular #7243
R.L.C. Starling (U. Leicester) and M. Stamatikos (GSFC/ORAU) report on behalf
of the Swift XRT team:
Swift XRT observed the field of possible GRB 080130 (Copete et al., GCN 7242)
found in the BAT Slew Survey, approximately 11 hours after the burst. In
1.98ks of Photon Counting (PC) mode data starting 2008-01-30:22:21 and ending
2008-01-30:22:54 we find one possible X-ray source inside the BATSS error
circle, detected at the 3-sigma level at RA,Dec=261.61657,-53.18878 deg
and equivalent to:
RA (J2000)= 17h 26m 27.98s
Dec(J2000)= -53d 11' 19.6"
with an uncertainty of 8.7 arsec (radius, 90% confidence). This is 2.1 arcmin
from the reported BATSS position.
At this stage we cannot tell if the source is fading or not and we have no
spectral information.
This is an official product of the Swift XRT team.
- GCN Circular #7244
P. D'Avanzo, S. Covino, L.A. Antonelli, D. Fugazza, L. Calzoletti, S.
Campana, G. Chincarini, M.L. Conciatore, S. Cutini, V. D'Elia, F.
Dalessio, F. Fiore, P. Goldoni, D. Guetta, C. Guidorzi, G.L. Israel,
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 the
field of the GRB 080130 (Copete et al., GCN 7242). Observations were
performed in the H-band on Jan 31.3041 (about 0.8 days after the burst ) .
We detect two objects inside the XRT error box (Starling & Stamatikos,
GCN 7243), both present in the 2MASS catalogue, at the following
coordinates (J2000):
A) R.A. = 17:26:27.71, Dec. = -53:11:20.3
B) R.A. = 17:26:29.22, Dec. = -53:11:20.3
with an uncertainty of 0.4". The magnitude of both objects seems to be
consistent with the value reported in the 2MASS catalogue. We note that
a third 2MASS object is present inside the XRT error box at the
coordinates (J2000):
C) R.A. = 17:26:28.76, Dec. = -53:11:14.4
but it is below our detection limit. No other sources are visible within
the XRT error box down to a limiting magnitude of H > 16.1 (3sigma c.l.
, calibrated against the 2MASS catalogue).
Sources A, B and C are also visible in the DSS image catalogue and seem
to have a stellar-like profile.
- GCN Circular #7245
P. Schady (MSSL-UCL), M. Stamatikos (GSFC/ORAU) report on behalf of the
Swift/UVOT team:
The Swift/UVOT observed the field of GRB080130 (Copete et al., GCN 7242)
approximately 11hrs after the possible burst, in the v, u, uvw1, uvm2 and
uvw2 filters. All three 2MASS sources mentioned by D'Avanzo et al. (GCN
7244) are detected in the UVOT observations. No new source is detected
within the XRT error circle (Starling et al., GCN 7243) in any of the UVOT
observations down to the following 3-sigma upper limits:
Filter Tmid (s) Exp.(s) 3-sig UL
v 40760 424 > 19.31
u 41979 248 > 19.47
uvw1 41631 424 > 19.68
uvm2 41195 424 > 19.79
uvw2 40324 424 > 19.07
The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E(B-V)=0.19 mag in the
direction of the burst (Schlegel et al. 1998).
- GCN Circular #7247
R.L.C. Starling, P.A. Evans, P.T. O'Brien (U. Leicester), C. Guidorzi
(U. Bicocca/INAF-OAB) and M. Stamatikos (GSFC/ORAU) report on behalf of
the Swift XRT team:
Swift XRT re-observed the field of possible ground-detected GRB 080130
(Copete et al., GCN 7242), approximately 34 hours after the burst. In
4.98ks of Photon Counting (PC) mode data starting 2008-01-31:16:01 and
ending 2008-01-31:20:51 we still detect an X-ray source inside the BATSS
error circle at the 3-sigma level (Starling and Stamatikos, GCN 7243). By
combining both XRT datasets for this field totalling ~7 ks we refine the
source position to RA,Dec=261.61484,-53.18742 deg, equivalent to:
RA (J2000)= 17h 26m 27.56s
Dec(J2000)= -53d 11' 14.7"
with an uncertainty of 5 arsec (radius, 90% confidence). This is 6.2
arcsec from the previously reported XRT position, and 2.2 arcmin from the
BATSS position.
The count rate of the source in this second observation is 0.004+/-0.001
counts/s. Compared to the earlier measured count rate of 0.010+/-0.002
counts/s we can confirm that the source has faded. We conclude that GRB
080130 was a real GRB, and that the source reported here is its X-ray
afterglow.
This is an official product of the Swift XRT team.
- GCN Circular #7248
J. Cummings (GSFC/UMBC), A. Copete, J. Grindlay, B. Allen, J. Hong (Harvard)
S. D. Barthelmy, N. Gehrels (GSFC), M. Stamatikos (GSFC/ORAU)
report:
Using the data set from T-3 to T+107 sec from recent telemetry
downlinks, we report further analysis of BAT GRB 080130
(T_zero chosen as 11:13:59 UT) detected during a Swift slew maneuver
(Copete, et al., GCN Circ. 7242). The BAT ground-calculated position
from postslew (after T+33 sec) data is RA, Dec = 261.632, -53.190 deg,
which is
RA(J2000) = 17h 26m 31.6s
Dec(J2000) = -53d 11' 24"
with an uncertainty of 2.8 arcmin, (radius, sys+stat, 90% containment).
The burst was in the fully coded field of view after the slew.
The mask-weighted light curve shows 3 peaks at about T+4, T+30, and
T+63 sec. T90 (15-350 keV) is 65 +- 5 sec (estimated error including
systematics).
The time-averaged spectrum from T-1 to T+68.0 sec is best fit by a
simple power-law model. The power law index of the time-averaged
spectrum is 1.21 +- 0.12. The fluence in the 15-150 keV band is
(7.7 +- 2.8) x 10^-7 erg/cm2. The 1-sec peak photon flux measured
from T+36 sec in the 15-150 keV band is 0.2 +- 0.1 ph/cm2/sec.
All the quoted errors are at the 90% confidence level.
- GCN Circular #8472
Aquib Moin (Curtin Institute of Radio Astronomy / Australia Telescope
National Facility), Steven Tingay (Curtin Institute of Radio Astronomy),
Chris Phillips (Australia Telescope National Facility), Gregory Taylor
(University of New Mexico), Mark Wieringa (Australia Telescope National
Facility) and Ralph Martin (Perth Observatory) report:
We observed the BAT refined position of the GRB 080130 (GCN 7248) at 4.8
and 8.456 GHz with the Australia Telescope Compact Array (ATCA) on May
31, 2008 between 09:15:05 UT and 13:07:05 UT.
We did not detect a radio source at the BAT position of the GRB 080130
(GCN 7248). The radio flux density at the GRB position is -0.153 +/-
0.246 mJy at 4.8 GHz, and 0.113 +/- 0.284 mJy at 8.6 GHz (1-sigma).
The Australia Telescope Compact Array (/ Parkes telescope / Mopra
telescope / Long Baseline Array) is part of the Australia Telescope
which is funded by the Commonwealth of Australia for operation as a
National Facility managed by CSIRO.
See field image at:
http://cira.ivec.org/dokuwiki/doku.php/grb/grb_080130_field_image
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