------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1796 2002 Aug 10 10.42UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK GMH at AST.STAR.RL.AC.UK WORLD WIDE WEB http://www.theastronomer.org ------------------------------------------------------------------- COMET C/2002 O6 Further to our report on TA E-Circular 1794, updated orbital elements have been derived by Dr. Brian Marsden and published on MPEC 2002-P28: T 2002 Sept 9.4180 TT w 78.69900 ) e 1.00000000 O 330.96400 ) 2000.0 q 0.4946900 A.U. i 58.64600 ) Source: MPEC 2002-P28 Positions are geocentric m = 10.0 + 5.0 log R + 10.0 log r The effect on the ephemeris on E-Circular 1794 is quite small: Date R.A. (2000) Dec. R r Elong Mag. Motion h m o ' (AU) (AU) o "/hr P.A. 2002 Aug 10.00 6 4.09 +16 45.1 0.259 0.856 46.6 6.4 902 49 11.00 6 23.16 +20 36.4 0.264 0.839 42.8 6.3 877 50 12.00 6 42.45 +24 10.0 0.271 0.822 39.4 6.3 835 52 13.00 7 1.70 +27 21.8 0.281 0.805 36.6 6.3 782 55 14.00 7 20.64 +30 9.4 0.293 0.789 34.3 6.3 722 57 15.00 7 39.02 +32 32.4 0.307 0.772 32.6 6.3 660 60 16.00 7 56.65 +34 31.8 0.323 0.756 31.4 6.3 598 63 17.00 8 13.35 +36 9.5 0.341 0.739 30.5 6.4 540 66 18.00 8 29.04 +37 27.9 0.361 0.723 30.0 6.4 486 69 19.00 8 43.65 +38 29.5 0.381 0.707 29.8 6.4 436 72 20.00 8 57.16 +39 16.7 0.403 0.691 29.7 6.4 392 75 21.00 9 9.61 +39 51.7 0.426 0.676 29.7 6.4 353 78 22.00 9 21.02 +40 16.4 0.450 0.661 29.9 6.5 318 81 23.00 9 31.47 +40 32.4 0.474 0.646 30.0 6.5 287 84 24.00 9 41.01 +40 41.1 0.499 0.631 30.2 6.5 261 87 25.00 9 49.70 +40 43.5 0.525 0.617 30.3 6.5 237 90 26.00 9 57.63 +40 40.5 0.552 0.604 30.5 6.5 217 93 27.00 10 4.86 +40 32.8 0.579 0.591 30.6 6.5 199 97 28.00 10 11.45 +40 21.1 0.606 0.578 30.6 6.5 184 101 29.00 10 17.46 +40 5.7 0.634 0.566 30.7 6.5 171 104 30.00 10 22.95 +39 47.0 0.662 0.555 30.7 6.5 160 108 31.00 10 27.96 +39 25.3 0.691 0.545 30.7 6.6 151 112 2002 Sept 1.00 10 32.54 +39 0.9 0.720 0.535 30.6 6.6 143 117 2.00 10 36.74 +38 33.9 0.749 0.527 30.5 6.6 138 121 3.00 10 40.60 +38 4.5 0.778 0.519 30.4 6.6 133 125 4.00 10 44.14 +37 32.8 0.807 0.512 30.2 6.6 130 129 5.00 10 47.41 +36 59.0 0.837 0.506 30.1 6.7 128 133 6.00 10 50.43 +36 23.3 0.866 0.502 29.8 6.7 127 136 7.00 10 53.23 +35 45.7 0.896 0.498 29.6 6.7 126 139 8.00 10 55.83 +35 6.4 0.925 0.496 29.3 6.8 126 142 9.00 10 58.26 +34 25.6 0.954 0.495 29.1 6.8 127 145 Martin Mobberley commented on the comet's visibility based on the original orbital elements: The comet is currently best placed at the start of morning astronomical twilight in the eastern sky, from the UK. It peaks in altitude in the morning astronomical twilight at 16 degrees altitude, due east, in the second week of August, at 6th mag. However, it drops to 6 degrees altitude by the end of August, in the northeast morning astronomical twilight, again, for UK observers. By early September, the comet also crawls above the northwest UK evening horizon, in nautical twilight; however, it will remain slightly higher in the morning sky. It should still be a 6th or 7th magnitude object by that time. Guy M Hurst