------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1056 1996 Mar 03 11.56UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England. Telephone/FAX(0256)471074 Int:+44256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK GMH at AST.STAR.RL.AC.UK WORLD WIDE WEB http://www.demon.co.uk/astronomer ------------------------------------------------------------------- COMET C/1996 B2 HYAKUTAKE Updated elements: T 1996 May 1.4025 TT w 130.19250 ) e 0.99984600 O 188.05140 ) 2000.0 q 0.2301230 A.U. i 124.90160 ) Source: MPC 26724 Positions are geocentric The following ephemeris by G.Hurst using EPH.EXE by N.James replaces that on E1047. The magnitude formula adopted by Brian Marsden on recent IAUCs is retained as clearly there remains considerable uncertainty about the comet's performance in the coming month. Latest results reaching the editor as of Mar 2 suggest the comet is still about one magnitude brighter than indicated below. m = 5.5 + 5.0 log R + 10.0 log r Date R.A. (2000) Dec. R r Elong Mag. Motion h m o ' (AU) (AU) o "/hr P.A. 1996 Mar 3.00 14 52.47 -22 9.4 0.752 1.479 115.4 6.6 48 18 4.00 14 52.89 -21 50.1 0.719 1.461 116.4 6.4 53 16 5.00 14 53.28 -21 28.6 0.685 1.442 117.4 6.3 58 13 6.00 14 53.65 -21 4.6 0.652 1.424 118.5 6.1 64 11 7.00 14 53.99 -20 37.7 0.619 1.405 119.6 5.9 72 9 8.00 14 54.30 -20 7.4 0.586 1.386 120.7 5.8 81 7 9.00 14 54.58 -19 33.2 0.553 1.367 121.8 5.6 91 6 10.00 14 54.83 -18 54.3 0.520 1.348 122.9 5.4 103 4 11.00 14 55.03 -18 9.8 0.487 1.329 124.1 5.2 118 3 12.00 14 55.18 -17 18.6 0.454 1.310 125.3 5.0 137 2 13.00 14 55.29 -16 19.0 0.422 1.291 126.6 4.7 159 1 14.00 14 55.33 -15 9.3 0.389 1.271 127.9 4.5 188 0 15.00 14 55.30 -13 46.6 0.357 1.251 129.2 4.2 224 359 16.00 14 55.19 -12 7.3 0.325 1.232 130.7 4.0 270 359 17.00 14 54.96 -10 6.3 0.294 1.212 132.1 3.7 332 358 18.00 14 54.60 -7 36.2 0.263 1.192 133.6 3.4 415 358 19.00 14 54.06 -4 26.4 0.232 1.172 135.1 3.0 530 357 20.00 14 53.28 -0 20.5 0.203 1.152 136.4 2.7 694 357 21.00 14 52.14 +5 6.0 0.175 1.131 137.3 2.3 932 357 22.00 14 50.45 +12 30.2 0.149 1.111 137.2 1.8 1279 357 23.00 14 47.83 +22 42.8 0.127 1.090 134.8 1.4 1764 356 24.00 14 43.42 +36 32.9 0.111 1.069 128.5 1.0 2340 356 25.00 14 34.73 +53 47.6 0.102 1.049 117.5 0.8 2752 354 26.00 14 10.66 +71 57.6 0.104 1.027 103.7 0.7 2665 350 27.00 10 33.71 +86 8.4 0.116 1.006 90.8 0.9 2039 306 28.00 4 5.49 +78 43.5 0.135 0.985 80.5 1.1 1614 200 29.00 3 32.61 +69 58.4 0.159 0.963 72.7 1.3 1166 191 30.00 3 22.07 +63 29.0 0.185 0.942 66.9 1.6 857 188 31.00 3 16.83 +58 37.8 0.214 0.920 62.4 1.8 646 187 Brian Marsden adds: The indications are that this is not a 'new' comet in the Oort sense and that it was last near the sun 10,000-20,000 years ago. He further warns that although recent visual results suggest the comet will a naked eye object, when at its closest approach to the earth (0.102AU on Mar 25.3UT) the brightness is likely to be diffused over an area several degrees across. The comet is unique in its close passage to the earth and subsequent small perihelion distance. If the brightness holds, it will be the intrinsically brightest comet to pass so close to the earth since 1556. IAUC 6329 Guy M Hurst