THE ASTRONOMER Electronic Circular No 571 1991 October 17 19.40UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP, England. Telephone: (0256)471074 Int:+44256471074 Telex: 9312111261 Answerback: TA G JANET BOXES: GMH at UK.AC.CAM.ASTRONOMY.STARLINK or GUYH at UK.AC.SUSSEX.CLUSTER TELECOM GOLD: 10074:MIK2885 PRESTEL 256471074 ------------------------------------------------------------------- COMET SHOEMAKER-LEVY (1991a1) Carolyn S. Shoemaker, Eugene M. Shoemaker, and David H. Levy report their discovery of comet. The following positions are available: 1991 UT R.A. (1950) Decl. m1 Observer Oct. 6.50243 2 40 01.38 +37 43 08.2 16.5 Shoemaker 7.45833 2 38 38.97 +37 47 07.3 " 8.32690 2 37 22.62 +37 50 39.7 " 9.12961 2 36 10.89 +37 53 47.2 McCrosky 9.14110 2 36 09.83 +37 53 49.9 " 10.06256 2 34 45.84 +37 57 17.5 " E. M. Shoemaker, C. S. Shoemaker, and D. H. Levy (Palomar). 0.46-m Schmidt films. Scanned by C. S. Shoemaker; measured by K. A. Lawler. On Oct. 8, the comet appeared strongly condensed with a coma and a short tail in p.a. 200 deg. R. E. McCrosky and C.-Y. Shao (Oak Ridge). 1.55-m reflector + CCD. Oct. 10 observation made through clouds. Preliminary parabolic orbital elements from the above observations: T = 1992 July 29.619 ET Peri. = 143.888 Node = 48.569 1950.0 q = 0.88387 AU Incl. = 113.914 IAUC 5363 Ephemeris by Hurst using a program by Nick James: m = 7.5 + 5.0 log R + 10.0 log r Date R.A. (1950) Dec. R r Elong Mag. Motion h m o ' (AU) (AU) o "/hr P.A. 1991 Oct 16.00 2 25.14 +38 15.8 3.222 4.092 146.7 16.2 51 277 21.00 2 16.30 +38 25.7 3.142 4.039 150.5 16.0 54 274 26.00 2 6.87 +38 29.4 3.071 3.985 153.4 15.9 57 270 31.00 1 57.01 +38 26.6 3.010 3.931 154.9 15.8 59 267 1991 Nov 5.00 1 46.85 +38 16.8 2.958 3.877 154.6 15.7 61 264 10.00 1 36.58 +38 0.1 2.917 3.823 152.5 15.6 61 261 15.00 1 26.39 +37 36.6 2.885 3.768 149.1 15.6 61 258 20.00 1 16.46 +37 7.1 2.863 3.713 144.6 15.5 60 255 25.00 1 6.95 +36 32.5 2.850 3.658 139.5 15.4 59 252 30.00 0 58.01 +35 53.8 2.846 3.602 134.1 15.3 56 249 1991 Dec 5.00 0 49.74 +35 12.4 2.849 3.547 128.4 15.3 53 246 10.00 0 42.21 +34 29.4 2.860 3.490 122.6 15.2 49 244 The comet could reach magnitude 7 or brighter and be well placed in the northern sky, during 1992 July. Guy M Hurst