Black List of lost ROSAT AO-1 Observations (updated 4.7.91 GRH) Start UT End UT Reason 7.2.91 7:11 - 9.2.91 5:12 SAFE MODE 9.2.91 23:07 - 10.2.91 20:58 WFC filter position mismatch 22.2.91 5:50 - 22.2.91 6:41 no guide stars 22.2.91 9:08 - 22.2.91 9:13 no guide stars 22.2.91 16:28 - 22.2.91 17:16 no guide stars 22.2.91 18:57 - 22.2.91 19:00 no guide stars 22.2.91 19:54 - 22.2.91 20:06 no guide stars 23.2.91 3:19 - 23.2.91 23:46 AMCS STANDBY: NO POINTINGS 25.2.91 1:23 - 25.2.91 2:02 guide star problems 27.2.91 9:02 - 27.2.91 13:35 WFC filter position mismatch 28.2.91 17:07 - 28.2.91 17:20 no reference stars 2.3.91 5:15 - 2.3.91 13:34 WFC data lost / tape allocation 2.3.91 10:17 - 2.3.91 16:54 FI data lost / tape allocation 3.3.91 23:45 - 5.3.91 18:51 AMCS STANDBY: NO POINTINGS 7.3.91 3:05 - 7.3.91 3:48 inconsistent attitude solution 7.3.91 16:00 - 7.3.91 16:36 inconsistent attitude solution 8.3.91 14:25 - 8.3.91 14:55 inconsistent attitude solution 11.3.91 19:20 - 11.3.91 19:40 inconsistent attitude solution 13.3.91 02:56 - 13.3.91 ca4h no reference stars 15.3.91 11:40 - 15.3.91 12:40 inconsistent attitude solution 15.3.91 13:30 - 15.3.91 14:20 inconsistent attitude solution 17.3.91 17:58 - 17.3.91 23:15 spurios WFC AMCS safing triggered, no WFC data 19.3.91 15:14 - 19.3.91 16:01 spurios WFC AMCS safing triggered, no WFC data 19.3.91 19:55 - 19.3.91 20:21 bad telemetry data 24.3.91 18:15 - 24.3.91 18:45 bad telemetry data 25.3.91 07:04 - 25.3.91 10:22 special attitude manoeuvers (gyro cal) 25.3.91 10:22 - 28.3.91 5:40 ca.75% lost due to solar activity (PSPC off) 28.3.91 10:35 - 28.3.91 18:20 SEU in WFC computer, no WFC data 30.3.91 8:34 - 30.3.91 10:15 spurios WFC AMCS safing triggered, no WFC data 4.4.91 3:05 - 4.4.91 6:55 WFC CDHS crash (SEU?), no WFC data 6.4.91 08:26 - 6.4.91 08:58 P27: reference stars: NONE, ONE or TWO 6.4.91 09:07 - 6.4.91 18:19 reference stars: NONE (mostly) 6.4.91 18:19 - 10.4.91 0:09 STANDBY, SAFE MODE, RECOVERY, FI turnon 8.4.91 19:42 - 8.4.91 ca22h no reference stars 14.4.91 18:40 - 14.4.91 ca21h no reference stars 21.4.91 17:00 - 22.4.91 1:49 guide star problems 22.4.91 1:49 - 23.4.91 0:55 STANDBY mode due to loss of attitude 23.4.91 18:51 - 23.4.91 20:28 WFC command conflict; no WFC data 23.4.91 22:25 - 24.4.91 2:30 Special gyro calibration slews 24.4.91 12:10 - 24.4.91 12:55 no guide stars 25.4.91 17:10 - 25.4.91 18:48 WFC command conflict; no WFC data 27.4.91 9:41 - 30.4.91 9:38 STANDBY, new AMCD software, SAFE MODE, FI turnon 2.5.91 15:40 - 2.5.91 19:06 FI coldstart and switch-on of Gas System; no FI 12.5.91 13:17 STANDBY, SAFE MODE Y-Gyro lost After the resumption of pointed observations with one target per day and quite severe pointing restrictions the format of the black list is changed, following the layout of the new mission timeline. Approximate loss times (real seconds, not net observing times) are indicated in kiloseconds together with the planned targets. Observation losses in the new ROSAT Timeline ____________________________________________ Observation Date Seqid Target Loss Reason 26 May - 27 May 200127 GL 411 all day AMCS pointing problems 27 May - 28 May 700208 MKN 231 all day AMCS safemode 28 May - 29 May 700218 1E1235+6315 full FI recovery 4 Jun - 5 Jun 700232 1202+281 30 ksec high countrate safeing 5 Jun - 6 Jun 600050 NGC4736 20 ksec 7 Jun - 8 Jun 700208 MKN231 30 ksec high countrate safeing 9 Jun - 10 Jun 300065 SS CYG all day AMCS pointing problems 11 Jun - 12 Jun 800066 Stephan's Q. 25 ksec high countrate safeing 12 Jun - 13 Jun 800039 N79-299A 10 ksec high countrate safeing 13 Jun - 14 Jun 200307 COM16 30 ksec high countrate safeing 14 Jun - 15 Jun 700223 ON 231 30 ksec high countrate safeing 20 Jun - 21 Jun 800047 Abell 1758 40 ksec spurious filter closeing 22 Jun - 23 Jun 700216 B21308+32 30 ksec high countrate safeing 5 Jul - 6 Jul 700117 3C294 full AMCS safemode 6 Jul - 7 Jul 200329 LHS2924 full AMCS safemode 7 Jul - 8 Jul 700095 Mkn478 full FI recovery 1 Sep - 2 Sep 800018 Anom 50 ksec new AMCS software activ. 10 Sep - 11 Sep 300115 M4 full commanding error 23.09 6:03 - 4U1755-33 AMCS Safemode BAADE'S WINDOW + loading and GALACTIC CENTER testing of MXB1659-29 new AMCS HVC Interf software - 27.09 1:05 4U1735-44 29.09 8:29 - 29.09 18:33 Draco cloud Filter wheel problems 1.10 13:29 - 2.10 8:27 LW Mon HRI HV off / Filter problems 9.10 4:54 - 10.10 19:34 47 Tuc F/W closed (new AMCS S/W) 11.10 9:49 - HR 7557 Switch PSPC-B to tank 1 Aql X-1 and flush for 3 days 1919+479 - 15.10 14:07 XY Uma 26.10 ? - 26.10 10:03 MS 1019.0 +51.38 no startracker (SEU) 4.11 3:37 - 4.11 5:42 MS1019.0+5138 HRI out of Sync. 4.11 7:47 - 4.11 8:37 HRI out of Sync. 7.11 5:13 - 7.11 8:33 HRI out of Sync. 8.11 1:48 - 8.11 3:19 HRI out of Sync. 8.11 10:08 - 8.11 11:15 HRI out of Sync Information entered until November 18. 1991 (GRH)