THE ASTRONOMER Electronic Circular No 541 1991 July 14 08.58UT 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 ------------------------------------------------------------------- PERIODIC COMET WIRTANEN (1991s) S. Nakano, Sumoto, Japan, reports that T. Seki, Geisei, has recovered this comet as shown below. The object is diffuse with condensation, and the indicated correction to the prediction on MPC 13046 (ephemeris on MPC 18148) is delta T = -0.05 day. 1991 UT R.A. (1950) Decl. m1 July 8.76666 3 12 02.7 + 8 03 58 17 9.77743 3 15 32.12 + 8 19 56.5 17 9.78333 3 15 33.57 + 8 20 03.8 IAUC 5303 PERIODIC COMET HARTLEY 2 (1991t) G. R. Kastel', Institute for Theoretical Astronomy, reports the following rough positions of a comet discovered by T. V. Kryachko at Majdanak. The object was diffuse and condensed with a coma 15' across. 1991 UT R.A. (1950) Decl. m1 July 9.854 1 01.5 +20 15 11 9.938 1 02.0 +20 05 10.875 1 06.2 +20 40 11 S. Nakano, Sumoto, Japan, has suggested that this is P/Hartley 2, a correction of delta T = -5.6 days being necessary to his prediction on MPC 13046. As a result, R. E. McCrosky and C.-Y. Shao were able to confirm the comet and its identification with the 1.5-m reflector at Oak Ridge Observatory, as follows: 1991 UT R.A. (1950) Decl. July 12.31995 1 12 48.80 +21 21 05.9 12.33093 1 12 51.82 +21 21 23.9 Orbital elements by Brian Marsden from 20 observations 1986-1991: Epoch = 1991 Sept. 21.0 ET T = 1991 Sept. 11.6515 ET Peri. = 174.9274 e = 0.719504 Node = 226.0600 1950.0 q = 0.953226 AU Incl. = 9.2552 a = 3.398363 AU n = 0.1573256 P = 6.265 years IAUC 5304 Ephemeris by Hurst using a program by N.James: m = 10.5 + 5.0 log R + 15.0 log r Date R.A. (1950) Dec. R r Elong Mag. Motion h m o ' (AU) (AU) o "/hr P.A. 1991 July 14.00 1 20.91 +22 6.4 0.900 1.281 83.6 11.9 183 69 15.00 1 25.86 +22 33.1 0.891 1.272 83.3 11.8 185 69 16.00 1 30.89 +22 59.5 0.883 1.263 83.0 11.8 187 69 17.00 1 36.01 +23 25.6 0.875 1.254 82.7 11.7 189 70 18.00 1 41.22 +23 51.3 0.868 1.245 82.4 11.6 191 70 19.00 1 46.53 +24 16.6 0.860 1.237 82.0 11.6 193 71 20.00 1 51.92 +24 41.5 0.853 1.228 81.6 11.5 195 72 21.00 1 57.40 +25 5.8 0.846 1.220 81.3 11.4 197 72 22.00 2 2.98 +25 29.7 0.840 1.211 80.9 11.4 199 73 23.00 2 8.64 +25 52.9 0.834 1.203 80.5 11.3 201 73 24.00 2 14.39 +26 15.5 0.828 1.195 80.1 11.2 202 74 25.00 2 20.23 +26 37.4 0.822 1.186 79.7 11.2 204 75 26.00 2 26.15 +26 58.5 0.817 1.178 79.2 11.1 206 75 27.00 2 32.15 +27 18.8 0.812 1.170 78.8 11.1 207 76 28.00 2 38.23 +27 38.3 0.807 1.162 78.3 11.0 209 77 29.00 2 44.39 +27 56.9 0.802 1.154 77.9 11.0 210 78 30.00 2 50.62 +28 14.6 0.798 1.146 77.4 10.9 211 78 31.00 2 56.93 +28 31.2 0.794 1.139 76.9 10.8 213 79 Guy M Hurst