Gamma-ray Burst 021206

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN notice #1727
  K. Hurley and T. Cline, on behalf of the Ulysses and Mars Odyssey GRB teams,
  I. Mitrofanov, D. Anfimov, A. Kozyrev, M. Litvak and A. Sanin, on behalf of the HEND/Odyssey GRB team, and
  W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on behalf of the GRS/Odyssey GRB team, report:
  Ulysses and HEND observed this burst at 81155 +/- 1104 s. The uncertainty is due to the fact that no near-Earth spacecraft has yet reported this event. As observed by Ulysses, it had a duration of approximately 20 seconds with a weak tail lasting perhaps another 40 seconds, a 25-100 keV fluence of approximately 1.6E-04 erg/cm2, and a peak flux of approximately 2.9E-05 erg/cm2 s over 0.50 seconds.
  We have triangulated it to a preliminary annulus centered at RA, Decl (2000)= 328.915, -57.580 degrees, with radius 81.125 +/- 0.014 degrees. (The uncertainty in the radius does not take into account the fact that HEND was driven into saturation by this burst; we will attempt to include this in later estimates). As this annulus does not pass near any of the known SGRs, we believe the event to be a GRB.
  We are expecting confirmation of this event by a near-Earth spacecraft, which will allow us to derive an error box for it.
• GCN notice #1728
  K. Hurley and T. Cline, on behalf of the Ulysses, Konus, and Mars Odyssey GRB teams,
  I. Mitrofanov, D. Anfimov, A. Kozyrev, M. Litvak and A. Sanin, on behalf of the HEND/Odyssey GRB team,
  W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on behalf of the GRS/Odyssey GRB team, and
  E. Mazets and S. Golenetskii, on behalf of the Konus-Wind GRB team, report:
  We have triangulated this exceptionally bright burst (GCN 1727) to a preliminary, 3 sigma error box whose approximate area is 57. sq. arcmin. and whose coordinates are:

      RA(2000)                              DEC(2000)
   ERROR BOX CENTER:   16 h  0 m 43.43 s     -9 o 43 '  24.20 " 
   ERROR BOX CORNER 1: 16 h  1 m 47.11 s     -9 o 27 '  53.80 " 
   ERROR BOX CORNER 2: 16 h  0 m  0.64 s     -9 o 55 '  35.00 " 
   ERROR BOX CORNER 3: 16 h  1 m 25.66 s     -9 o 31 '  18.70 " 
   ERROR BOX CORNER 4: 15 h 59 m 38.66 s     -9 o 59 '   4.81 " 
  

  This error box may be improved, but unfortunately it lies only about 18 degrees from the Sun.
• GCN/IPN POSITION NOTICE
  

  TITLE:             GCN/IPN POSITION NOTICE
  NOTICE_DATE:       Sun 08 Dec 02 17:56:52 UT
  NOTICE_TYPE:       IPN Single Box
  IPN_NUMBER:        450
  GRB_DATE:          12614 TJD;   340 DOY;   02/12/06
  GRB_TIME:          81155.00 SOD {22:32:35.00} UT
  GRB_IPN_RA:        240.1809d {+16h 00m 43s} (J2000),      
                     240.2209d {+16h 00m 53s} (current),
                     239.4995d {+15h 57m 60s} (1950)
  GRB_IPN_DEC:        -9.7233d {-09d 43' 23"} (J2000),     
                      -9.7314d {-09d 43' 52"} (current),
                      -9.5834d {-09d 35' 00"} (1950)               
  GRB_ERROR1_RA1:    240.4462d {+16h 01m 47s} (J2000)
  GRB_ERROR1_DEC1:    -9.4649d {-09d 27' 53"} (J2000)
  GRB_ERROR1_RA2:    240.0026d {+16h 00m 01s} (J2000)
  GRB_ERROR1_DEC2:    -9.9263d {-09d 55' 34"} (J2000)
  GRB_ERROR1_RA3:    240.3569d {+16h 01m 26s} (J2000)
  GRB_ERROR1_DEC3:    -9.5218d {-09d 31' 17"} (J2000)
  GRB_ERROR1_RA4:    239.9110d {+15h 59m 39s} (J2000)
  GRB_ERROR1_DEC4:    -9.9846d {-09d 59' 04"} (J2000)
  GRB_ERROR:         22.21 [arcmin radius of circumscribing circle, 3 sigma]
  GRB_BOX_AREA:      57 [sq.arcmin]           
  GRB_PEAK_FLUX:     2.9e-05 [erg/cm2/sec in 25-100 keV] in a 0.50 sec interval
  GRB_FLUENCE:       1.6e-04 [erg/cm2 in 25-100 keV]
  GRB_DURATION:      20.0 [sec]   
  SUN_POSTN:         253.33d {+16h 53m 19s}  -22.55d {-22d 33' 13"}
  SUN_DIST:           17.95 [deg]
  MOON_POSTN:        291.20d {+19h 24m 49s}  -25.47d {-25d 27' 57"}
  MOON_DIST:          50.74 [deg]
  GAL_COORDS:        0.81,31.17 [deg] galactic lon,lat of the burst
  ECL_COORDS:        240.08,10.67 [deg] ecliptic lon,lat of the burst
  COMMENTS:          IPN triangulation localization.               
  COMMENTS:          This is a preliminary, 3 sigma error box.
  COMMENTS:          GCN message is being issued. 
  

• GCN notice #2280
  D. A. Frail (NRAO) reports on behalf of a larger collaboration:
  "Using the VLA, we imaged the inner quarter of the initial IPN error box of the exceptionally bright gamma-ray burst GRB 021206 (Hurley et al. GCN#'s 1727, 1728). In initial observations made at 4.86 GHz during the first week after the burst, there was an unresolved radio source with a flux density of ~400 uJy located at r.a.=16:00:46.85, dec.=-09:42:33.5 (J2000), with an uncertainty of about 0.6 arcsec. Subsequent measurements at 4.86 and 8.46 GHz in February and March 2003 showed that the source has faded by a least a factor of five. Future observations are planned to place tighter limits on the flux density of this radio source.
  Although the magnitude of the radio flux density and the temporal behavior of the light curve are typical of past GRB afterglows, we cannot rule out the possibility (probability <=0.02) that this is an unrelated background variable (Frail et al. AJ, 125, 2299, 2003). Given the recent RHESSI detection of polarized emission from this burst (Coburn & Boggs, Nature, 423, 415, 2003) we encourage further followup optical observations of this candidate afterglow."
  This message may be cited.
• GCN notice #2281
  K. Hurley and T. Cline, on behalf of the Ulysses, Mars Odyssey, and Konus GRB teams,
  D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger, W. Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team,
  I. Mitrofanov, S. Charyshnikov, V. Grinkov, A. Kozyrev, M. Litvak, and A. Sanin, on behalf of the HEND-Odyssey GRB team,
  W. Boynton, C. Fellows, K. Harshman, C. Shinohara and R. Starr, on behalf of the GRS/Odyssey GRB team,
  E. Mazets and S. Golenetskii, on behalf of the Konus-Wind GRB team, and
  A. von Kienlin, G. Lichti, and A. Rau, on behalf of the INTEGRAL SPI-ACS GRB team, report:
  Using the final spacecraft timing and ephemeris data, we have combined Ulysses, RHESSI, Mars Odyssey, Konus, and INTEGRAL (SPI-ACS) data to obtain a final IPN error ellipse for this burst (GCN 1727, 1728; Nature 423, 415, 2003) whose area is a factor of ~7 smaller than that of the error box announced in GCN 1728. The 3 sigma error ellipse is centered at RA, Decl (2000)=240.195, -9.710 degrees, with major axis 20.4 arcminutes, minor axis 0.53 arcminutes, and position angle ~18 degrees. Its area is 8.6 square arcminutes. The VLA source (GCN 2280) lies within both the earlier error box and within this ellipse, roughly 0.020 degrees from its center. A map and a lightcurve have been posted at ssl.berkeley.edu/ipn3/021206.
  
• GCN notice #2341
  T. Fatkhullin reports on behalf of the SAO RAS follow-up team:
  The field of GRB021206 (GCN #1727, see also Coburn & Boggs 2003, Nature, 423, 415) was observed with 6 meter telescope of SAO RAS. The observations were carried out with SCORPIO instument (see the Web-page http://www.sao.ru/hq/moisav/scorpio/scorpio.html) on 26 July 2003 during late evening twilight. The 15 1-min R-band exposures were obtained starting from UT 26.7556 to 26.7896 July 2003. The field was centered on the radio transient positions (Frail, GCN #2280). Astrometry of the exposures sum was made using USNO A2.0 stars and errors obtained are 0.6 arcsec in R.A and Dec. Within the astrometry error circle at the position of radio transient we did not detect any obvious optical source down to about R=24.8 (3 sigma). But from about 2 arcsec to the North-West an extended dim emission are observed. We should note that due to highlights from very bright star on the image we caution about reality of this extended emission. Photometric calibration was performed relatively to SExtractor (Bertin & Arnouts 1996, A&AS, 117, 393) photometry of unsaturated USNO stars in our field of view. The sum of exposures can be seen at our anonymous FTP-site ftp://ftp.sao.ru/pub2/grb/GRB021206/
  This message can be cited.
• GCN notice #2350
  H. Pedersen, B. L. Jensen (CUO), A. J=E4rvinen (NOT) and M. I. Andersen (AIP) report:
  On 2003 August 2.92 UTC, we observed the position of the VLA afterglow candidate (GCN #2280, #2341; Coburn & Boggs 2003, Nature, 423, 415) with the 2.5-m Nordic Optical Telescope, La Palma. We obtained 10 R-band exposures, each of 10 min duration, in a seeing of 0.9" FWHM.
  According to a standard calibration, we estimate that any unresolved object at the VLA position is fainter than m(R) = 25.4 (2 sigma).
  A box-car smoothed 45" x 45" section is displayed on:
  http://www.astro.ku.dk/~holger/g/GRB021206.gif
  
• 0710.2858from 15 Oct 2007
  Wigger: Observation of an unexpected hardening in the spectrum of GRB 021206
  Abstract: GRB 021206 is one of the brightest GRBs ever observed. Its prompt emission, as measured by RHESSI, shows an unexpected spectral feature. The spectrum has a peak energy of about 700 keV and can be described by a Band function up to 4.5 MeV. Above 4.5 MeV, the spectrum hardens again, so that the Band function fails to fit the whole RHESSI energy range up to 17 MeV. Nor does the sum of a blackbody function plus a power law, even though such a function can describe a spectral hardening. The cannonball model on the other hand predicts such a hardening, and we found that it fits the spectrum of GRB 021206 perfectly. We also analysed other strong GRBs observed by RHESSI, namely GRBs 020715, 021008, 030329, 030406, 030519B, 031027, 031111. We found that all their spectra can be fit by the cannonball model as well as by a Band function.