Gamma-ray Burst 041226

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN notice #2914
  

  TITLE:   GCN GRB OBSERVATION REPORT
  NUMBER:  2914
  SUBJECT: GRB041226: Swift-BAT detection of a burst
  DATE:    04/12/26 23:31:39 GMT
  FROM:    Hans Krimm at NASA-GSFC  
  

  H. Krimm (GSFC/USRA), D. Palmer (LANL), S. Barthelmy (GSFC), L. Barbier (GSFC), M. Chester (PSU), J. Cummings (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hinshaw (GSFC), D. Hullinger (GSFC/UMD), C. Markwardt (GSFC/UMD), K. McLean (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC), G. Sato (ISAS), M. Suzuki (Saitama), G. Tagliaferri (OAB), J. Tueller (GSFC), A. Wells (U Leicester) on behalf of the Swift-BAT team:
  At 20:34:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB041226. The spacecraft did not autonomously slew to the burst since automated slewing was not yet enabled.
  The BAT ground-calculated location is RA,Dec 79.544,73.349 (J2000) with an uncertainty of 6 arcmin (radius, 3-sigma, including a systematic uncertainty). The lightcurve is multi-peaked with a main emission duration of ~20 s, with 4 counts/cm^2 fluence and a peak (1 second interval) of ~0.5 counts/cm^2/s in the 15-350 keV band.
• GCN notice #2915
  

  TITLE:   GCN GRB OBSERVATION REPORT
  NUMBER:  2915
  SUBJECT: GRB041226: ROTSE-III Optical Observations
  DATE:    04/12/27 03:02:30 GMT
  FROM:    Eli Rykoff at U of Michigan/ROTSE  
  

  E. Rykoff (U. Michigan) reports on behalf of the ROTSE collaboration:
  ROTSE-IIIb, located at McDonald Observatory, Texas, responded to Swift GRB041226 (GCN #2914). An automatic response was initiated during early twilight hours. The first usable image taken at 27 Dec. 00:46:47 UT, 4.2 hours after the burst. We took 300 20-s exposures. All the images were taken with >99% moon illumination. The unfiltered images were calibrated relative to USNO A2.0. Individual images have limiting magnitudes improving from 15 to 16.8 as the sky darkened. Comparison to DSS (second epoch) reveals no new sources within the 3-sigma error circle to a limiting magnitude of 16.1 for stacks of 10 images taken 4.2 hours after the burst and 17.7 for stacks of 10 images taken 5 hours after the burst.
• GCN notice #2961
  A. J. Castro-Tirado, M. Jel=EDnek, A. de Ugarte Postigo, (IAA-CSIC Granada), S. Vitek (Czech Technical University,=20 Prague), P. Kubanek (Astronomical Institute of the Academy=20 of Sciences, Ondrejov), T. J. Mateo Sanguino (Universidad=20 de Huelva), J. M. Castro Cer=F3n (U. Copenhagen), T. Soria=20 (EELM-CSIC, M=E1laga) and J. Fabregat (Universidad de Valencia)
  report: The BOOTES-2 very wide field camera, located at the Estaci=F3n Experimental de La Mayora (EELM-CSIC) in M=E1laga, observed=20 the two regions of the sky containing the SWIFT/BAT error=20 boxes for GRB 041224 (Barthelmy et al. GCN 2908) and GRB=20 041226 (Krimm et al. GCN 2914) as part of its routine=20 observing schedule. For GRB 041224 a 30 s exposure started=20 at 20:21:00 UT (3 s after the onset of the 50 s long burst),=20 with the following frame starting at 20:22:00 UT. For GRB 041226 the 30 s exposure started at 20:34:00 (19 s prior to=20 the onset of the 20 s main emission peak). Limiting (unfiltered)=20 magnitudes of 8.5 and 7.0 respectively (due to the presence=20 of the full moon) are derived for any promt optical flash arising from either of these two events.
  This message can be quoted.