Joseph A. Dellinger posted obs by Bill Dillon at the George Observatory near Houston, Texas: Rosetta C2005 03 01.18294 11 06 40.09 +02 24 00.0 17.0 R 735 Rosetta C2005 03 01.19055 11 06 37.60 +02 24 03.7 17.0 R 735 Rosetta C2005 03 01.19689 11 06 35.47 +02 24 06.6 17.0 R 735 > the mags are really "unfiltered", but "R" is a good approximation. Mag 17 is very bright for the range, about 0.0089 A.U. (1.33 million km). See appended ephemeris. My formula predicts mag 21. Had the object been only 1000 km away, it would have been mag 1.4, unlikely for Rosetta's non-specular, 2.8 x 2.1 x 2.0 m box-like body. Rosetta's low phase angle, 6.8 deg (see S-T-O column in ephemeris), meant that the observer was almost directly between it and the Sun. Since its large solar array (32 m span) is aimed at the Sun, it seems likely to have been flaring, i.e. sending a bright specular reflection toward the observer. Imagine an observer on Earth between the Sun and Rosetta in this artist's conception: http://satobs.org/seesat_ref/Rosetta/Rosetta.jpg The unusually bright obs at Czechia, some 22 h later, was made under similar conditions, with phase angle near 5.8 deg: http://satobs.org/seesat/Mar-2005/0022.html Ted Molczan Target Body: Rosetta (Spacecraft) Observer Location: Houston, TX Coordinates: 95°21'37.1''W, 29°45'25.9''N From: A.D. 2005-03-01 04:23 UT To: A.D. 2005-03-01 04:44 ******************************************************************************* Date__(UT)__HR:MN R.A._(ICRF/J2000.0)_DEC delta deldot S-T-O ******************************************************************************* 2005-Mar-01 04:23 11 06 39.86 +02 23 54.2 0.0089222014 -4.19264 6.8419 2005-Mar-01 04:24 11 06 39.64 +02 23 54.6 0.0089205194 -4.19124 6.8406 2005-Mar-01 04:25 11 06 39.42 +02 23 54.9 0.0089188379 -4.18984 6.8393 2005-Mar-01 04:26 11 06 39.19 +02 23 55.2 0.0089171571 -4.18843 6.8380 2005-Mar-01 04:27 11 06 38.97 +02 23 55.5 0.0089154768 -4.18702 6.8367 2005-Mar-01 04:28 11 06 38.74 +02 23 55.9 0.0089137970 -4.18560 6.8354 2005-Mar-01 04:29 11 06 38.51 +02 23 56.2 0.0089121179 -4.18418 6.8341 2005-Mar-01 04:30 11 06 38.29 +02 23 56.5 0.0089104393 -4.18275 6.8328 2005-Mar-01 04:31 11 06 38.06 +02 23 56.9 0.0089087613 -4.18132 6.8315 2005-Mar-01 04:32 11 06 37.83 +02 23 57.2 0.0089070838 -4.17988 6.8302 2005-Mar-01 04:33 11 06 37.60 +02 23 57.5 0.0089054070 -4.17844 6.8289 2005-Mar-01 04:34 11 06 37.37 +02 23 57.8 0.0089037307 -4.17700 6.8276 2005-Mar-01 04:35 11 06 37.14 +02 23 58.2 0.0089020550 -4.17555 6.8263 2005-Mar-01 04:36 11 06 36.90 +02 23 58.5 0.0089003799 -4.17410 6.8250 2005-Mar-01 04:37 11 06 36.67 +02 23 58.8 0.0088987054 -4.17264 6.8237 2005-Mar-01 04:38 11 06 36.44 +02 23 59.1 0.0088970314 -4.17118 6.8224 2005-Mar-01 04:39 11 06 36.20 +02 23 59.5 0.0088953581 -4.16971 6.8211 2005-Mar-01 04:40 11 06 35.97 +02 23 59.8 0.0088936853 -4.16824 6.8198 2005-Mar-01 04:41 11 06 35.73 +02 24 00.1 0.0088920132 -4.16676 6.8184 2005-Mar-01 04:42 11 06 35.50 +02 24 00.4 0.0088903416 -4.16529 6.8171 2005-Mar-01 04:43 11 06 35.26 +02 24 00.7 0.0088886707 -4.16380 6.8158 2005-Mar-01 04:44 11 06 35.02 +02 24 01.1 0.0088870003 -4.16232 6.8145 ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Thu Mar 03 2005 - 09:43:05 EST
