TITLE: GCN CIRCULAR NUMBER: 5987 SUBJECT: Retractions of previous Swift-BAT triggers DATE: 07/01/03 18:53:10 GMT FROM: Scott Barthelmy at NASA/GSFC S. Barthelmy (GSFC) on behalf of the Swift-BAT Team This corrects the classification of 27 Swift-BAT triggers since the beginning of the mission. In a few cases over the two year period, we did not issue retraction announcements when there should have been one (in either Notice or Circular form), for various reasons (e.g. we got busy with the next trigger, we did not believe it was a non-GRB until just recently, or we just plain forgot). In some cases the classification issued in the real-time notice was wrong. For example, some notices said a trigger was cause by a GRB when in fact it was a known source in a variable state, but the source was not in the catalog used for the real-time notices. In other cases the real-time classification was indecisive (i.e. it contained words like "possible"). We apologize for any inconvenience that the original incorrect classifications may have caused. In a few cases we thought we did not need to retract the trigger because we thought nobody outside the Swift team was notified, when in fact partial sets of Notices went out to the community. A hole in the GCN Notice filtering code was allowing the FOM_OBS and SC_SLEW Notices to be distributed to the world. That filtering code correctly blocked the bogus BAT_POS and BAT_LIGHTCURVE Notices, but allowed the other two through. The table below contains the Trigger Number, the Trigger Date and Time, and a Comment about what we are currently classifying the trigger. TRIGNUM DATE TIME DESCRIPTION 106416 05 Feb 19 14:14:47 FSW bug, old ACS, Vela X-1 misidentified 114292 05 Apr 10 08:38:17 FSW bug, old ACS, Crab mididentified 114959 05 Apr 19 05:47:21 Noise fluctuation 117883 05 May 07 00:21:28 FSW bug, old ACS, known source misidentified 118087 05 May 07 13:33:52 Chance noise coinc with SAX0835.9+5118 123171 05 May 20 11:15:04 Noise fluctuation 131113 05 May 31 23:31:57 S/C drifting in Sun_Reference Safe_Hold mode 131156 05 Jun 01 04:24:45 S/C drifting in Sun_Reference Safe_Hold mode 131160 05 Jun 01 05:17:27 S/C drifting in Sun_Reference Safe_Hold mode 131177 05 Jun 01 10:07:47 S/C drifting in Sun_Reference Safe_Hold mode 131185 05 Jun 01 12:34:21 S/C drifting in Sun_Reference Safe_Hold mode 131213 05 Jun 01 14:55:47 S/C drifting in Sun_Reference Safe_Hold mode 131266 05 Jun 01 22:13:56 S/C drifting in Sun_Reference Safe_Hold mode 131395 05 Jun 02 10:41:45 S/C drifting in Sun_Reference Safe_Hold mode 142851 05 Jun 26 03:30:20 Chance noise coinc with SAX2224.9+5421 146134 05 Jul 15 23:56:08 FSW Bug, bad RA,Dec long Image-trigger 146547 05 Jul 18 13:20:32 FSW Bug, bad RA,Dec long Image-trigger 147704 05 Jul 25 15:57:52 FSW Bug, bad RA,Dec long Image-trigger 147857 05 Jul 26 19:33:36 Chance noise coinc with 4U 1746-370 148146 05 Jul 30 04:14:48 FSW bug, bad RA,Dec values in the notice 148715 05 Aug 02 23:56:16 Bad ACS, roll-only maneuver, Cyg X-1 152762 05 Aug 30 17:13;12 Noise in the Image-domain 158262 05 Oct 04 11;16:48 Chance noise coinc with EXO 0748-676 (or Possibly real EXO detection) 163240 05 Nov 09 21:33:36 Chance noise coinc with IGR00234+6141 178754 06 Jan 24 17:17:35 Chance noise coinc with sw333.4+17.4 (Probably) 179477 06 Jan 29 17:18:39 Chance noise coinc with IGR14175-4641 203045 06 Mar 28 13:50:14 Chance noise coinc with 1E1743.1-2843