------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1582 2000 Nov 28 14.25UT 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.demon.co.uk/astronomer ------------------------------------------------------------------- COMET C/2000 W1 (UTSUNOMIYA-JONES) On Nov. 19, S. Nakano, Sumoto, Japan, reported the visual discovery on Nov. 18 by Syogo Utsunomiya (Aso, Kumamoto; 25x150 binoculars) of a possible comet with coma diameter 5' moving rapidly southeastward in Vela. Attempts by several observers (including A. Hale, D. Seargent, J. Biggs, T. Urata, and J.Kobayashi) to confirm the object, at the request of Nakano and the Central Bureau, were unsuccessful. On Nov. 25, A. C. Gilmore (Mount John University Observatory) reported the visual discovery of an apparent comet by Albert F. Jones (Nelson, New Zealand, 0.078-m f/8 refractor, 30x) while observing the variable star T Aps at dawn; Jones reported the comet as being diffuse with coma diameter about 4' in morning twilight. The possibility that Jones' object might be the same as that reported by Utsunomiya was explored by the Central Bureau, and a search ephemeris from plausible parabolic orbital elements fitted to the Nov. 18 and 25 approximate positions was circulated to numerous southern-hemisphere observers. Confirming CCD astrometry was made by Gilmore with the 1.0-m f/7.7 reflector at Mt. John. 2000 UT R.A. (2000) Decl. m1 Observer Nov. 18.817 9 04.0 -41 22 8.5 Utsunomiya 25.64 13 49.8 -77 05 8 Jones 26.42295 15 36 22.31 -76 23 51.5 Gilmore 26.56207 15 52 59.84 -76 00 25.6 " The following preliminary parabolic orbital elements by B. G. Marsden are heavily weighted toward the Mt. John accurate positions: T = 2000 Dec. 26.56 TT Peri. = 51.52 Node = 10.81 2000.0 q = 0.3214 AU Incl. = 160.16 IAUC 7526 The following ephemeris is by Guy Hurst using EPH.EXE by Nick James. The editor notes that although the comet could reach magnitude 6.0 in late December, the comet will then be a few degrees from the sun and presumably unobservable. m = 10.5 + 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. 2000 Nov 28.00 17 45.63 -69 32.6 0.303 0.825 50.1 7.1 1029 40 29.00 18 23.08 -64 13.5 0.320 0.804 47.3 7.1 923 31 30.00 18 45.56 -59 7.7 0.341 0.783 45.0 7.1 816 25 2000 Dec 1.00 19 0.15 -54 28.9 0.364 0.762 43.2 7.1 714 22 2.00 19 10.20 -50 20.1 0.390 0.741 41.6 7.2 623 19 3.00 19 17.40 -46 40.4 0.418 0.720 40.3 7.2 543 17 4.00 19 22.72 -43 27.0 0.448 0.698 39.2 7.2 473 15 5.00 19 26.71 -40 36.8 0.480 0.677 38.2 7.2 414 14 6.00 19 29.72 -38 6.6 0.512 0.655 37.2 7.2 363 12 7.00 19 31.97 -35 53.7 0.545 0.634 36.3 7.2 320 11 8.00 19 33.63 -33 55.6 0.579 0.613 35.4 7.2 284 9 9.00 19 34.79 -32 10.3 0.614 0.591 34.4 7.2 252 7 10.00 19 35.53 -30 35.9 0.649 0.570 33.5 7.1 225 5 11.00 19 35.91 -29 11.1 0.685 0.549 32.5 7.1 202 2 12.00 19 35.96 -27 54.6 0.721 0.528 31.5 7.0 183 359 13.00 19 35.70 -26 45.3 0.758 0.507 30.4 6.9 166 356 14.00 19 35.17 -25 42.5 0.794 0.486 29.3 6.9 152 351 15.00 19 34.35 -24 45.4 0.831 0.466 28.2 6.8 141 347 Guy M Hurst