Compton Observatory Science Report #127 Thursday, July 7, 1993 Eric Chipman, Compton Observatory Science Support Center Questions or comments can be sent to the Compton SSC. Phone 301/286-7764, e-mail SPAN GROSSC::CHIPMAN, Internet chipman@grossc.gsfc.nasa.gov. Science operations are continuing. Detailed study of selected options for the reboost procedure is underway. Since all of these options include use of the B-side OATs (Orbital Adjustment Thrusters), the priming of the fuel lines to these thrusters is planned to be started later this month. BATSE ----- Currently an international campaign is being conducted to make multi-wavelength observations of the Be/X-ray binary system EXO 2030+375 near its periastron passage. Periastron passage occurred on June 28th. Pulsations at the pulsar spin period of 41.67 s we first detected in the BATSE data for June 29th. On July 2nd, the pulsed flux (peak to valley) at 45 keV was 2.1+-.1 x 10^-4 photons/cm^2/s/keV. The pulsed flux was detected from 20-100 keV and fit a power law spectrum with an index of 3.5 +- .2. The outburst is expected to last for about 10 days, based on the duration of the 12 previous outbursts seen by BATSE. The x-ray binary GX 301-2 is currently in outburst. Both its pulsed flux and total flux have been rising over the past week. The total flux in the 20-50 keV band on July 6th was ~0.6 Crab. As of July 7rd, BATSE has detected 699 cosmic gamma-ray bursts out of a total of 2328 on-board triggers in 806 days of operation. There have been 663 triggers due to solar flares with emission above 60 keV. COMPTEL ------- Most of the COMPTEL Team members are attending a meeting of the COMPTEL collaboration at MPE in Garching, Germany to review the instrument performance to date, and the status of flight data processing and associated scientific analysis. EGRET ----- EGRET operations were normal this week. The instrument continues to collect data while the next step in the reboost attempt is considered. Work continues on the summaries of the phase I results and the first part of phase II. The current viewing direction will be held for four weeks and will permit a somewhat deeper study of a region than has been possible recently; however, the data collection efficiency is still well below that before the tape recorder failure. OSSE ---- OSSE operations are normal. In the second week of viewing period 227, the Z-axis target continues to be the recent supernova SN 1993J, and the X-axis target continues to be the radio pulsar PSR 0740-28 (PI team). Because the Sun is not available on the OSSE scan plane, the slewing response to BATSE solar flare triggers is disabled. Other Items: ------------ The following is the latest timeline for Phase 2 of the Compton Mission. Note that the viewing periods beyond 225 have been renumbered and redated relative to some relent timeline versions. 6/29/93 COMPTON PHASE 2 VIEWING PLAN AS OF JUNE 29, 1993 GRO Z-AXIS* VIEW +Z-AXIS* GRO Z-AXIS* GALACTIC GRO X-AXIS* ---OSSE PRIMARY TARGET--- ----OSSE SECONDARY TARGET-- PER. START TARGET RA DEC LONG LAT RA DEC TARGET RA DEC TARGET RA DEC --------------------------------------------------------------------------------------------------------------------------------- 201 11/17/92 HER X-1 253.15 42.26 66.79 39.28 266.02 -47.01 HER X-1 254.46 35.34 G PLANE 355 263.30 -33.17 202 11/24/92 HER X-1 251.55 45.40 70.85 40.50 270.04 -43.08 HER X-1 254.46 35.34 G CENTER 266.40 -28.94 203.0 12/01/92 CYGNUS 306.59 39.34 77.85 0.69 258.44 -39.15 CYG X-1 299.59 35.21 G CENTER 266.40 -28.94 203.3 12/08/92 CYGNUS 306.59 39.34 77.85 0.69 264.05 -41.96 CYG X-1 299.59 35.21 G CENTER 266.40 -28.94 203.6 12/15/92 CYGNUS 306.59 39.34 77.85 0.69 258.44 -39.15 CYG X-1 299.59 35.21 G CENTER 266.40 -28.94 204 12/22/92 3C 273 188.99 -0.74 294.70 61.88 279.50 -34.03 3C 273 187.28 2.05 G PLANE 355 263.30 -33.17 205 12/29/92 3C 273 188.84 -1.03 294.47 61.58 279.32 -24.79 3C 273 187.28 2.05 G PLANE 5 269.27 -24.64 206 01/05/93 3C 273 188.99 -0.74 294.70 61.88 279.50 -34.30 3C 273 187.28 2.05 G PLANE 355 263.30 -33.17 207 01/12/93 IC 4329A 203.86 -30.41 314.06 31.51 293.35 0.86 IC 4329A 207.33 -30.31 PSR 1822-09 276.25 -9.00 208 02/02/93 NGC 4507 198.47 -41.93 307.39 20.75 296.86 -9.24 NGC 4507 188.90 -39.91 NGC 6814 295.67 -10.31 209 02/09/93 2CG 010-31 305.69 -40.81 0.24 -34.01 297.95 48.93 2CG 010-31 304.75 -31.84 3C 390.3 280.56 79.76 210 02/22/93 GAL CENTER 257.65 -29.10 355.62 6.28 351.03 -6.03 1E 1740-2942 265.98 -29.72 MCG -2-58-22 346.18 -8.69 211 02/25/93 GAL 123-05 18.38 58.05 125.86 -4.70 8.08 -31.53 4U 0115+634 19.86 62.49 47 TUC 5.83 -72.07 212 03/09/93 WR 140 298.65 50.54 84.33 11.43 341.61 -31.07 WR 140 305.12 43.85 NGC 7314 338.94 -26.05 213 03/23/93 CRAB PULSAR 80.30 22.29 182.63 -8.22 348.47 4.44 CRAB PULSAR 83.52 22.02 MRK 509 311.04 -10.72 214 03/29/93 GAL CENTER 257.65 -29.10 355.62 6.28 351.03 -6.03 1E 1740-2942 265.98 -29.72 MCG -2-58-22 346.18 -8.69 215 04/01/93 CEN A 203.26 -39.28 311.66 22.89 53.56 -46.55 CEN A 201.37 -43.02 SN 1987A 83.86 -69.27 216 04/06/93 SN 1993J 143.64 71.46 140.75 38.11 3.37 14.47 SN 1993J 148.84 69.02 M31 10.68 41.27 217 04/12/93 CEN A 203.26 -39.28 311.66 22.89 53.56 -46.55 CEN A 201.37 -43.02 SN 1987A 83.86 -69.27 218 04/20/93 NGC 4151 180.75 43.09 151.41 71.26 31.04 42.71 SN 1993J 148.84 69.02 NGC 4151 182.64 39.41 219.1 05/04/93 REBOOST THRUSTER TESTING 219.4 05/05/93 GAL CENTER 245.35 -27.22 350.10 15.86 341.26 -11.31 1E 1740-2942 265.98 -29.72 MCG -2-58-22 346.18 -8.69 219.7 05/07/93 REBOOST CALIBRATION BURN 220 05/08/93 SMC 24.11 -72.07 298.09 -44.63 69.97 12.70 SMC X-1 19.18 -73.44 3C 120 68.30 5.35 221 05/13/93 CRAB PULSAR 85.21 19.46 187.52 -5.88 326.68 53.49 CRAB PULSAR 83.52 22.02 PSR 1951+32 298.24 32.89 222 05/24/93 NGC 4151 178.02 42.25 157.79 70.63 60.65 26.85 NGC 4151 182.64 39.41 MCG +8-11-11 88.73 46.44 223 05/31/93 GAL CENTER 265.98 -29.72 359.14 -0.09 316.33 48.19 1E 1740-2942 265.98 -29.72 CYG X-3 308.11 40.96 224 06/03/93 SMC 24.11 -72.07 298.09 -44.63 69.97 12.70 SMC X-1 19.18 -73.44 3C 120 68.30 5.35 225 06/15/93 REBOOST 226 06/19/93 GAL 355+05 258.44 -30.35 355.00 5.00 189.52 31.57 G CENTER 266.40 -28.94 COMA CLUSTER 194.90 27.96 227 06/29/93 SN 1993J 143.64 65.00 148.11 41.22 116.97 -22.62 SN 1993J 148.84 69.02 PSR 0740-28 115.71 -28.38 228 07/13/93 SN 1993J 145.33 63.18 149.85 42.69 131.74 -26.16 SN 1993J 148.84 69.02 VELA PULSAR 128.92 -45.18 229 07/27/93 GAL 5+05 264.60 -22.06 5.00 5.00 188.59 30.82 G CENTER 266.40 -28.94 COMA CLUSTER 194.90 27.96 230 08/03/93 VELA PULSAR 129.38 -48.16 266.17 -4.28 121.03 41.53 VELA PULSAR 128.92 -45.18 MRK 78 115.67 65.18 231 08/10/93 NGC 6814 289.94 -15.33 22.22 -13.08 186.93 -39.38 NGC 6814 295.67 -10.31 NGC 4507 188.90 -39.91 232 08/17/93 GAL 348+00 258.02 -39.35 347.50 0.00 188.46 23.07 GPLANE 347.5 258.02 -39.35 MRK 421 166.11 38.21 09/07/93 end Phase 2 * Z-axis is pointing direction for COMPTEL and EGRET. OSSE points in X-Z plane. RA and DEC are J2000.