Gamma-ray Burst 000408

On April 8, 2000 a GRB was detected by Ulysses, BATSE (#8069) and NEAR.

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN notice #626
  K. Hurley, S. Barthelmy, R. M. Kippen, and T. Cline, on behalf of the Ulysses, BATSE, and NEAR GRB teams, report:
  Ulysses, BATSE, and NEAR observed GRB000408 (=BATSE 8069) at 9348 s UT. As observed by Ulysses, this burst had a T90 duration of 2.5 s, a 25-100 keV fluence of 7.4x10^-6 erg/cm^2, and a peak flux over 0.5 s of 3.7x10^-6 erg/cm^2 s. Preliminary triangulation gives a ~200 sq. arcmin. error box with the following coordinates:

      RA(2000)                 DEC(2000)
  9 h 10 m 31.86 s    66 o 34 '  35.72 "  (CENTER)
  9 h 14 m 57.83 s    66 o 30 '  25.93 "  (CORNER)
  9 h  7 m 41.72 s    66 o 33 '  18.90 "  (CORNER)
  9 h 13 m 19.82 s    66 o 35 '  43.51 "  (CORNER)
  9 h  5 m 56.89 s    66 o 38 '  22.95 "  (CORNER)
  

  It should be possible to refine this error box considerably within 24 h, when the high time resolution data become available.
• GCN notice #628
  H. S. Park, R. Porrata (LLNL), G. G. Williams, D. Hartmann (Clemson), K. Hurley (UCB), S. Barthelmy (GSFC) report on behalf of the LOTIS collaboration:
  The realtime BATSE trigger came at 7:37 pm local time when the sky was too bright for observation. However, Lotis' wide-field-of-view sky patrol data covered the grb000408 IPN error box (GCN 626) 1.64 hours after the burst (15241s UTC). Comparison of the images with the previous sky patrol images, the Digital Sky Survey, and the Guide Star Catalog reveal no OT within the IPN error box brighter than m = 15.0 (5-sigma). No astronomical filter was used during these observations. Further analysis is in progress.
• GCN notice #629
  K.S. Baliyan, U.C. Joshi, S. Mondal, S. Chandrasekhar, J.K. Jain and B.G. Anandrao (MIRO-PRL, Ahmedabad, India) report:
  Optical afterglow follow up observations of the grb000408 were made covering IPN error box (GCN 626) on April 9, 2000, beginning 16:15 UT. The 1024*1024 CCD (FOV 6'*6') mounted on 1.2 M IR telescope at Mt Abu IR Observatory, operated by Physical Research Laboratory, Ahmedabad- India, was used to get 600 seconds exposures each in V and I filters at each location covering the error box. The data analysis is in progress and an image will be put on the laboratory web page when available. We also intend to continue observations of the optical counterpart tonight as well.
• GCN notice #632
  K. Hurley, R. M. Kippen, and T. Cline, on behalf of the Ulysses, BATSE, and NEAR GRB teams, report:
  We have derived a refined error box for GRB000408 (=BATSE 8069, GCN 626), whose area is ~60 sq. arcmin. Its coordinates are:

    RA(2000)                 DEC(2000)            
  9 h  9 m 17.91 s     +66 o 34 '  49.78 "  (CENTER)
  9 h 11 m 30.33 s     +66 o 32 '  31.07 "  (CORNER)
  9 h  8 m 10.97 s     +66 o 33 '  43.86 "  (CORNER)
  9 h 10 m 24.59 s     +66 o 35 '  54.27 "  (CORNER)
  9 h  7 m  3.18 s     +66 o 37 '   2.96 "  (CORNER)
  

• GCN notice #633
  A. Henden (USRA/USNO), C. Luginbuhl (USNO), B. Canzian (USNO) on behalf of the USNO GRB Team, Vijay Mohan and Ram Sagar, UPSO (Nainital), David Alcalde, IAC (Tenerife), Jose Maria Castro Ceron, ROA (San Fernando), Alberto Castro-Tirado, LAEFF-INTA (Madrid) and IAA-CSIC (Granada), and Javier Gorosabel Urkia, DSRI report:
  We have observed the entire preliminary IPN error box for GRB 000408 (GCN#626) as well as the refined error box (GCN#632) from several sites and on both available nights. Because of the shape of the error box, mosaics were used at each site, limiting the depth of exposure for any particular field. Only R-band observations were made. A log of the observations is given below.

  TEL.       MARCH (UT)      TEXP   RA      DEC    
  --------------------------------------------------
  IAC80   8.9352 --  9.0103  3800 9:10:41 +66:34:15
  IAC80   9.0094 --  9.0140   200 9:09:39 +66:34:15
  IAC80   9.0141 --  9.0187   200 9:08:39 +66:34:47
  IAC80   9.0176 --  9.0223   200 9:07:42 +66:35:15
  IAC80   9.0210 --  9.0257   200 9:06:41 +66:35:47
  IAC80   9.0248 --  9.0294   200 9:11:41 +66:34:50
  IAC80   9.0292 --  9.0338   200 9:12:40 +66:34:21
  IAC80   9.0327 --  9.0373   200 9:13:42 +66:33:52
  IAC80   9.0360 --  9.0407   200 9:14:41 +66:33:20
  IAC80   9.0360 --  9.0407   200 9:14:41 +66:33:20
  IAC80   9.9319 --  9.9741  3600 9:08:26 +66:33:28
  UPSO    9.7667 --  9.7724   500 9:48:41 +66:35:15
  UPSO    9.7764 --  9.7821   500 9:10:27 +66:35:08
  USNO    9.136  --  9.225   1800 9:13:41 +66:33:51
  USNO    9.128  --  9.216   1800 9:12:02 +66:33:51
  USNO    9.121  --  9.209   1800 9:10:20 +66:33:51
  USNO    9.145  --  9.233   1800 9:08:41 +66:33:51
  USNO    9.153  --  9.241   1800 9:07:01 +66:33:51
  USNO   10.154  -- 10.176   1800 9:13:41 +66:33:51
  USNO   10.176  -- 10.198   1800 9:12:02 +66:33:51
  USNO   10.130  -- 10.152   1800 9:10:20 +66:33:51
  USNO   10.199  -- 10.229   1800 9:08:41 +66:33:51
  USNO   10.229  -- 10.251   1800 9:07:01 +66:33:51
  

  POSS-II/F for this field is not available through DSS. However, it is available through the USNO PMM pixel database. We have placed three files on the anon ftp server that cover the error box:

  
  ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb000408-1.jpg
  
  ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb000408-2.jpg
  
  ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb000408-3.jpg
  

  in order of increasing RA. A finder chart from POSS-I with the refined error box marked on it is at: http://www.dsri.dk/~jgu/grb000408/grb000408.dss.gif which is appended below.

  No candidate was found above the POSS-II plate limit. The two deep exposure sets from USNO were blinked to look for transients below the POSS-II plate limit. While several candidates are present, none is entirely convincing at a limiting magnitude of approximately R=21.5. However, for completeness, here are the two best candidates inside the error box, both R=20.5 or fainter:

  A  09:11:04.82  +66:33:31.3  J2000
  B  09:08:51.36  +66:33:36.5  J2000
  

  Preliminary BVRI all-sky calibration of the central part of the error box can be found at ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb000408.dat The external zero-point errors for this file are estimated to be +/- 0.05mag. Refinement of this photometry will be performed in late April if an OT is discovered.