------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1308 1998 May 27 21.30UT 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 P/1998 K4 (MUELLER 3) J. V. Scotti, Lunar and Planetary Laboratory, reports his recovery of comet P/1990 S1 (= 1990l = 1990 XIII) with the Spacewatch telescope on Kitt Peak. The comet is very slightly diffuse, with a coma diameter of 12" on May 26.45 UT. The indicated correction to the prediction by S. Nakano on MPC 27081 is Delta T = -0.7 day. 1998 UT R.A. (2000) Decl. m2 May 24.43002 21 31 51.97 -11 59 36.1 20.6 24.44144 21 31 52.30 -11 59 34.0 21.4 24.45263 21 31 52.66 -11 59 33.5 21.1 26.44283 21 32 53.34 -11 56 56.4 21.2 26.45382 21 32 53.76 -11 56 55.5 21.2 26.47267 21 32 54.27 -11 56 54.6 21.0 The following improved orbital elements, by Brian Marsden, satisfy 24 observations 1990-1998 with mean residual 1".0: Epoch = 1999 Mar. 3.0 TT T = 1999 Mar. 20.5047 TT Peri. = 225.4492 e = 0.288718 Node = 137.9665 2000.0 q = 3.010484 AU Incl. = 9.4137 a = 4.232474 AU n = 0.1131912 P = 8.707 years 1998 TT R. A. (2000) Decl. Delta r Elong. Phase m2 May 17 21 27.57 -12 12.1 3.147 3.397 95.6 17.2 21.1 27 21 33.16 -11 56.2 2.987 3.376 103.8 16.9 20.9 June 6 21 37.23 -11 49.1 2.834 3.354 112.4 16.2 20.8 16 21 39.64 -11 52.2 2.689 3.333 121.4 15.1 20.6 26 21 40.28 -12 06.6 2.557 3.313 130.9 13.4 20.4 July 6 21 39.09 -12 32.8 2.441 3.293 140.9 11.2 20.2 16 21 36.15 -13 10.4 2.345 3.273 151.3 8.6 20.0 26 21 31.67 -13 57.7 2.273 3.254 162.1 5.5 19.8 Aug. 5 21 26.07 -14 51.7 2.226 3.236 173.2 2.1 19.5 15 21 19.93 -15 48.5 2.207 3.218 175.5 1.4 19.4 25 21 13.91 -16 43.7 2.216 3.200 164.2 4.9 19.7 Sept. 4 21 08.74 -17 33.3 2.251 3.184 153.1 8.2 19.8 14 21 04.99 -18 14.4 2.311 3.167 142.3 11.2 20.0 24 21 03.09 -18 44.9 2.392 3.152 132.0 13.7 20.2 Oct. 4 21 03.28 -19 04.1 2.489 3.137 122.1 15.7 20.3 IAUC 6919 Martin Mobberley