GRB 050202
GCN Circular 3005
Subject
GRB 050202: Short burst detected by Swift-BAT
Date
2005-02-02T05:16:55Z (20 years ago)
From
Craig Markwardt at NASA/GSFC/UMD <craigm@milkyway.gsfc.nasa.gov>
J. Tueller (GSFC), L. Antonelli (INAF-OAR), S. Barthelmy,
L. Barbier (GSFC), D. Burrows (PSU), J. Cummings (GSFC), E. Fenimore (LANL),
N. Gehrels, K. Gendreau (GSFC), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), K. McLean (LANL), J. Nousek (PSU),
D. Palmer (LANL), A. Parsons (GSFC), S. Piranmonte (ASDC),
T. Sakamoto (GSFC), G. Sato (ISAS), M. Suzuki (Saitama), A. Wells (Leicester)
on behalf of the Swift-BAT team:
Swift-BAT detected a burst at 03:35:14.79 UT. The BAT on-board
calculated location is RA,Dec 290.560, -38.720 (J2000) with an
uncertainty of 4 arcmin (radius, 3-sigma, including a systematic
uncertainty).
This appears to be a short burst (single spike, duration of ~400
msec), dominated by emission in the 25-100 keV band. The peak rate is
approximately 3000 ct/s.
However, there are some longer-term variations (~150 sec) in the
lowest energy band (15-25 keV). These could be due to (a)
magnetospheric variations, (b) variations of the galactic sources in
the field of view, or (c) intrinsic GRB variations. When more
complete data is available, we should be able to remove this
ambiguity.
GCN Circular 3006
Subject
GRB 050202: Optical observations with LCO40
Date
2005-02-02T18:05:31Z (20 years ago)
From
Edo Berger at Carnegie Obs <eberger@ociw.edu>
E. Berger (Carnegie Observatories) and W. Krzeminski (Las Campanas
Observatory) report:
"We imaged the 4-arcmin radius error circle of GRB 050202 (GCN 3005) with
the Swope 40-inch telescope at Las Campanas Observatory on February 2.40
UT (6 hours after the burst) in R-band. Observations were taken at high
airmass and with a high sky background (as the Sun was rising) and as a
result reach a limit of only R~16 mag. To this limit we do not find any
objects within or near the error circle which are not present in the DSS.
We note that with a time delay of six hours, this limit is of similar
quality to any of the limits obtained to date (Hurley et al. 2002, ApJ,
567, 447)"
This message may be cited.
GCN Circular 3007
Subject
GRB050202: Radio Observations
Date
2005-02-02T21:06:50Z (20 years ago)
From
Dale A. Frail at NRAO <dfrail@nrao.edu>
D. A. Frail (NRAO) and A. M. Soderberg (Caltech) report on behalf of
the Caltech-NRAO-Carnegie GRB Collaboration:
"We used the VLA to make observations of the short burst GRB050202
detected by Swift (GCN#3005). The full BAT error circle was imaged at
frequencies of 1.43 GHz and 4.86 GHz to an rms noise level of 210
microJy/beam and 40 microJy/beam, respectively. No emission is
detected above the 5-sigma level at either frequency.
Further observations are planned."
GCN Circular 3009
Subject
GRB 050202: Second epoch radio observations
Date
2005-02-03T22:39:40Z (20 years ago)
From
Dale A. Frail at NRAO <dfrail@nrao.edu>
D. A. Frail (NRAO) and A. M. Soderberg (Caltech) report on behalf of
the Caltech-NRAO-Carnegie GRB Collaboration:
"A second observation was made with the VLA of the short burst
GRB050202 detected by Swift (GCN#3005) on February 3.82 UT. Comparison
with the first epoch on February 2.67 UT (GCN#3007) shows no new radio
sources in the BAT error circle. The rms noise the images is 267
microJy, 52 microJy, and 100 microJy at 1.43, 4.86 and 8.46 GHz
respectively.
No further observations are planned."
GCN Circular 3010
Subject
Further analysis of the short Swift-BAT GRB 050202
Date
2005-02-03T23:28:27Z (20 years ago)
From
Takanori Sakamoto at NASA/GSFC <sakamoto@hp.phys.titech.ac.jp>
T. Sakamoto (GSFC), S. Barthelmy, L. Barbier, J. Cummings (GSFC),
E. Fenimore (LANL), N. Gehrels, D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
G. Sato (ISAS), M. Suzuki (Saitama), J. Tueller (GSFC),
on behalf of the Swift-BAT team:
We have continued the analysis of Swift-BAT GRB 050202 (Tueller, et al.,
GCN Circ 3005). The refined position is 290.575, -38.735 (J2000)
with an uncertainty of 4 arcmin (radius, statistical plus systematic).
We find that the T_90 time for this burst is 0.080 sec. The ~150 sec
long-term variation on which the spike rides (Circ 3005) has been shown
to be due to Sco X-1. A fluctuation from Sco X-1 also contributed
to the larger duration value given in Circ 3005.
We have fit the burst spectrum with power-law: index 1.4 +-/0.3.
This short burst is in the intermediate hard range.
In the 15-350 keV band, the fluence is 6.5e-8 erg/cm2 and the peak flux
is 4.8 ph/cm2/sec.
We note that the the Swift spacecraft did not slew to this burst
because the burst location was within the Sun observing constraint.
GCN Circular 3018
Subject
short/hard GRB 050202, optical observations
Date
2005-02-09T19:00:19Z (20 years ago)
Edited On
2024-11-18T09:46:13Z (6 months ago)
From
Alberto Castro-Tirado at Inst.de Astro. de Andalucia <ajct@iaa.es>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
A.J. Castro-Tirado (IAA-CSIC, Granada),
I. Bond (Massey Univ., Auckland),
P. Kilmartin (Univ. of Canterbury),
A. de Ugarte Postigo, J. Gorosabel,
M. Jelínek (IAA-CSIC), and Ph. Yock
(Univ. of Auckland) report:
"Following the detection by SWIFT of the
short/soft GRB 050202 (Tueller et al. GCN
Circ. 3005) we imaged the error box with
the 0.6 m telescope at Mt. John University
Observatory. We obtained 3 x 300s images
with the MOA camera (+ wide R-band filter)
starting on 2.674 Feb (i.e. 12.6 hr after
the event). Observations were performed
at high airmass, prior to the sunrise.
Comparison of the stacked image with the
DSS-2 plates revealed no variable source
to about R = 20."