Compton Observatory Science Report #135 Thursday, September 2, 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. There was a maneuver performed on Tuesday, August 24, 1993, which was not reported last week. This was the initial maneuver to the attitude of period 232 (OSSE targets GPLANE 347.5 and MRK 421). The maneuver times were 1353Z to 1421Z, through an angle of 86.94 degrees, leaving a boom angle wrt the equator of 47.4 degrees. Options for the reboost scenario are being studied intensively. In all options, the reboost will not occur before October. No firm schedule is available yet. BATSE ----- The BATSE instrument is operating normally. Many BATSE scientists are in the process of preparing papers for the upcoming conferences. The discrete source team requests that any incipient transient sources wait until November for their outburst. As of August 30th, BATSE has detected 752 cosmic gamma-ray bursts out of a total of 2402 on-board triggers in 860 days of operation. There have been 664 triggers due to solar flares with emission above 60 keV. COMPTEL ------- The COMPTEL instrument is performing well and continues routine observations. The COMPTEL operations group reports that the observable sky has been relatively quiet this week, at least in medium-energy gamma rays. EGRET ----- EGRET operations were normal this week. With the start of Phase 3, a new approach to analysis has to be initiated to take into account the new rules for source distribution to investigators. Additional definitions are needed to complete this work, and this matter has been brought to the attention of the Project Scientist and the Users Committee Chairman. Data is being transferred to the Compton Observatory Science Support Center on schedule. Interaction with Phase 2 guest investigators and other scientists with whom we are working continues at a good level. We are waiting for further information from the project on Phase 3 guest investigators in order to support fully that program. Scientific analysis and writing is weighted towards the forthcoming Compton Symposium on September 20-22, 1993. OSSE ---- OSSE operations are normal. For this second week of viewing period 232.5, the Z-axis target is the Galactic plane near 347.5 degrees longitude (PI team). The X-axis targets for detectors 1 and 2 are NGC 4388 and M87 (PI team), while detectors 3 and 4 perform a trial mapping strategy for the sky survey of the Virgo region later in Phase 3. When neither target is above the Earth's limb, engineering data are being collected to improve the energy calibration of the "high" spectral range, nominally >10 MeV. The Sun is not available on the OSSE scan plane, so the slewing response to BATSE solar flare triggers is disabled. There have been no slews to the Sun since the last report. Other Items: ------------ The following is the latest Phase 3 Timeline for Compton GRO. Changes since the previous version are minor, primarily in some maneuver dates to avoid sun angle constraints, and in the tentative reboost date. COMPTON PHSE 3 VIEWING PLAN AS OF AUGUST 26, 1993 Z-axis is pointing direction for COMPTEL and EGRET. OSSE points in X-Z plane. RA and DEC are J2000. 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 301 08/17/93 VELA PULSAR 128.92 -45.18 263.59 -2.74 161.94 39.80 VELA PULSAR 128.92 -45.18 QSO 1028+313 157.74 31.05 232* 08/24/93 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 38.21 232.5* 08/26/93 GAL 348+00 258.02 -39.35 347.50 0.00 182.10 16.48 GPLANE 347.5 258.02 -39.35 NGC 4388 186.44 12.66 302.0 09/07/93 N CYG 1992 307.63 52.63 89.13 7.82 202.99 10.92 N CYG 1992 307.63 52.63 NGC 5548 214.50 25.13 302.5 09/14/93 N CYG 1992 307.63 52.63 89.13 7.82 208.83 6.66 N CYG 1992 307.63 52.63 PKS 1413+135 213.99 13.33 303.0 09/28/93 CEN A 201.37 -43.02 309.52 19.42 205.22 46.92 CEN A 201.37 -43.02 MRK 279 208.26 69.30 303.5 10/04/93 REBOOST (TENTATIVE) 303.7 10/08/93 CEN A 201.37 -43.02 309.52 19.42 205.22 46.92 CEN A 201.37 -43.02 MRK 279 208.26 69.30 304 10/19/93 VIRGO 278+59 180.01 -1.62 277.60 58.70 270.91 -28.89 VIRGO 278+59 180.01 -1.62 G CENTER 0+0 266.40 -28.94 305 10/26/93 VIRGO 278+63 181.58 2.06 277.70 62.70 270.38 -30.16 VIRGO 278+63 181.58 2.06 G CENTER 0+0 266.40 -28.94 306 11/02/93 VIRGO 278+67 183.29 5.68 278.20 66.70 271.03 -21.61 VIRGO 278+67 183.29 5.68 PSR 1800-21 270.96 -21.61 307 11/09/93 VIRGO 269+69 181.19 9.53 268.69 69.24 252.79 -61.99 VIRGO 269+69 181.19 9.53 GPLANE 324 232.93 -56.20 308 11/16/93 VIRGO 283+75 187.61 12.59 283.22 74.65 258.54 -55.65 VIRGO 283+75 187.61 12.59 GPLANE 332 243.91 -50.82 309 11/23/93 VIRGO 284+75 187.69 12.41 283.70 74.50 272.61 -21.93 VIRGO 284+75 187.69 12.41 PSR 1800-21 270.96 -21.61 310 11/30/93 GEMINGA 98.48 17.77 195.14 4.27 201.46 35.02 GEMINGA 98.48 17.77 NGC 4151 182.63 39.41 311 12/13/93 VIRGO 284+75 187.69 12.41 283.70 74.50 272.61 -21.93 VIRGO 284+75 187.69 12.41 PSR 1800-21 270.96 -21.61 312 12/20/93 VIRGO 281+71 185.52 9.12 280.50 70.70 271.83 -21.80 VIRGO 281+71 185.52 9.12 PSR 1800-21 270.96 -21.61 313 12/27/93 VIRGO 289+79 190.10 16.12 289.30 78.70 270.42 -30.20 VIRGO 289+79 190.10 16.12 G CENTER 0+0 266.40 -28.94 314 01/03/94 GAL 304-01 195.69 -63.83 304.18 -0.99 277.55 3.99 PSR 1259-63 195.69 -63.83 N HER 1991 281.63 12.24 315 01/16/94 GAL 304-01 195.69 -63.83 304.18 -0.99 282.83 1.41 PSR 1259-63 195.69 -63.83 G CENTER 0+0 266.40 -28.94 316 01/23/94 CEN A 201.37 -43.02 309.52 19.42 310.35 -19.21 CEN A 201.37 -43.02 CTA 102 338.15 11.73 317 02/01/94 NGC 1068 37.41 10.61 158.48 -45.38 306.06 7.18 3C 120 68.29 5.35 CTA 102 338.15 11.73 318 02/15/94 GAL 015+06 268.94 -13.18 14.79 6.00 5.76 -26.89 GPLANE 15 274.47 -15.90 NGC 253 11.88 -25.29 319 02/22/94 QSO 0716+714 110.48 71.34 143.98 28.02 341.13 12.08 QSO 0716+714 110.48 71.34 PKS 2155-304 329.72 -30.22 320 03/08/94 GAL 083-45 345.81 8.87 83.09 -45.47 76.45 4.13 NGC 7469 345.81 8.87 3C 120 68.29 5.35 321 03/15/94 GAL 357-11 276.44 -37.11 356.85 -11.29 349.25 21.35 1H 1822-371 276.44 -37.11 QSO 2251+158 343.49 16.13 322 04/01/94 MRK 421 157.18 32.26 194.76 58.73 14.17 51.67 QSO 1028+313 157.74 31.05 MRK 3 93.91 71.03 323 04/15/94 GAL 357-11 276.44 -37.11 356.85 -11.29 349.25 21.35 1H 1822-371 276.44 -37.11 QSO 2251+158 343.49 16.13 324 04/19/94 GAL 016+05 270.89 -12.83 16.03 4.51 358.13 11.96 GPLANE 15 274.47 -15.90 NGC 7469 345.81 8.87 325 04/26/94 GAL 147-09 49.07 46.94 147.04 -9.04 67.24 -41.60 GT 0236+610 40.14 61.22 SN 1987A 83.86 -69.27 326 05/10/94 NGC 3227 156.69 31.65 195.92 58.31 47.37 28.24 QSO 1028+313 157.74 31.05 NRAO 140 54.13 32.31 327 05/17/94 GAL 083-45 345.81 8.87 83.09 -45.47 81.19 31.01 NGC 7469 345.81 8.87 NRAO 140 54.13 32.31 328 05/24/94 PSR 1951+32 298.76 28.07 64.87 -0.03 69.89 50.97 CYG X-3 308.11 40.96 PSR 0611+22 93.56 22.42 329 05/31/94 GAL 253-42 69.26 -47.25 253.40 -42.00 88.04 41.18 PSR J0437-47 69.26 -47.25 CRAB PULSAR 83.52 22.02 330 06/07/94 GAL 018+00 275.93 -13.26 18.00 0.00 341.41 60.41 GPLANE 18 275.93 -13.26 GT 0236+610 40.14 61.22 331 06/14/94 PSR 1951+32 298.76 28.07 64.87 -0.03 69.89 50.97 CYG X-3 308.11 40.96 PSR 0611+22 93.56 22.42 332 06/21/94 GAL 018+00 275.93 -13.26 18.00 0.00 341.41 60.41 GPLANE 18 275.93 -13.26 GT 0236+610 40.14 61.22 333 07/05/94 PSR 1951+32 298.76 28.07 64.87 -0.03 69.89 50.97 CYG X-3 308.11 40.96 PSR 0611+22 93.56 22.42 334 07/12/94 GAL 006-04 273.86 -26.03 5.81 -4.30 238.09 58.96 GPLANE 15 274.47 -15.90 HER X-1 254.46 35.34 335 07/19/94 GAL 253-42 69.26 -47.25 253.40 -42.00 107.01 36.16 PSR J0437-47 69.26 -47.25 GEMINGA 98.48 17.77 336 08/01/94 GAL 083-45 345.81 8.87 83.09 -45.47 81.19 31.01 NGC 7469 345.81 8.87 NRAO 140 54.13 32.31 337 08/08/94 PKS 0528+134 87.70 0.98 205.00 -13.00 178.49 39.05 PSR 0656+14 104.70 14.23 NGC 4151 182.63 39.41 338 08/29/94 VELA PULSAR 128.92 -45.18 263.59 -2.74 200.60 17.34 VELA PULSAR 128.92 -45.18 3C 273 187.28 2.05 339 09/20/94 3C 317 234.71 -1.82 4.05 40.40 143.62 -30.89 PG 1416-129 214.77 -13.18 MCG -5-23-16 146.92 -30.96 10/04/94 end Phase 3 * Phase 2 target