THE ASTRONOMER Electronic Circular No 596 1992 Jan 7 19.09UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England. Telephone/FAX(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 MUELLER (1991h1) On 1991 Dec. 18 Jean Mueller reported her discovery of a probable comet on a single exposure on Dec. 13 by C. Brewer, D. Mendenhall and herself with the 1.2-m Oschin telescope in the course of Palomar Sky Survey II. The object was diffuse with a possible faint tail to the southwest. The discovery has now been confirmed on a film obtained on Dec. 31 by E. M. Shoemaker, C. S. Shoemaker and D. H. Levy with the 0.46-m Schmidt. The following measurements are all by Mueller: 1991 UT R.A. (2000) Decl. m1 Observer Dec. 13.48264 9 38 56.16 +42 31 23.9 17.5 Mueller 13.52778 9 38 53.58 +42 31 53.0 " 31.35486 8 58 02.50 +47 38 09.3 16 Shoemaker 31.39444 8 57 52.55 +47 38 58.2 " IAUC 5420 Elements: T 1992 Mar 21.1960 TDT w 307.01100 ) e 1.00000000 O 288.79500 ) 2000.0 q 0.1987100 A.U. i 95.52400 ) Source: IAUC 5421 Positions are geocentric m = 13.0 + 5.0 log R + 10.0 log r Ephemeris by Hurst using a program developed by N.James: Date R.A. (2000) Dec. R r Elong Mag. Motion h m o ' (AU) (AU) o "/hr P.A. 1992 Jan 4.00 8 40.81 +48 54.5 0.913 1.817 146.7 15.4 142 291 9.00 8 8.81 +50 29.5 0.808 1.731 150.1 14.9 183 283 14.00 7 25.07 +51 25.2 0.716 1.643 149.9 14.4 233 273 19.00 6 29.65 +50 50.8 0.642 1.553 144.7 14.0 288 260 24.00 5 28.12 +47 51.3 0.589 1.461 134.8 13.5 336 247 29.00 4 30.10 +42 10.0 0.561 1.366 121.7 13.1 362 235 1992 Feb 3.00 3 42.39 +34 34.1 0.558 1.268 107.2 12.8 355 227 8.00 3 5.90 +26 22.6 0.578 1.167 92.8 12.5 323 221 13.00 2 38.35 +18 36.9 0.616 1.063 79.4 12.2 279 218 18.00 2 16.96 +11 44.3 0.666 0.954 67.2 11.9 238 216 23.00 1 59.35 +5 47.4 0.723 0.841 56.3 11.5 206 216 28.00 1 43.58 +0 38.5 0.785 0.722 46.2 11.1 185 219 Although the comet could reach magnitude 6 in mid March, the solar elongation will be only 11 degrees and the object will fade rapidly thereafter. SUPERNOVA 1991bj IN IC 344 C. Pollas, Observatoire de la Cote d'Azur, reports his discovery of a supernova of mag 18.8 in IC 344 (mag 15) on exposures with the 0.9-m Schmidt telescope on 1991 Dec. 30.9 and 31.9 UT. The object is at R.A. = 3h39m01s.27, Decl. = -4d49'23".5 (equinox 1950.0), the offset from the nucleus being 14".0 east, 7".6 north. A nearby star of mag 16 is located R.A. = 3h38m59s.67, Decl. = -4d49'14".8, and one of mag 17 is at end figures 58.81, 15.2. IAUC 5420 CY UMA Patrick Schmeer, Germany, reports a superoutburst of this variable: 1991 Dec 16.06UT, [14.0; 24.142, 12.2; 27.922, 12.7; 29.001, 12.7. The previous observed supermaximum occurred in 1990 Sept(IAUC 5094) Guy M Hurst