THE ASTRONOMER Electronic Circular No 503 1991 Mar 30 16.05UT 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 ------------------------------------------------------------------- P/COMET MRKOS (1991k) Revised elements: T 1991 Mar 19.3420 E.T. w 180.68100 ) e 0.56280000 O 1.01500 ) 1950.0 q 1.4139700 A.U. i 31.71900 ) Source: IAUC 5220 Positions are geocentric Ephemeris (cf E497) by G.Hurst from a program by N.James: m = 13.0 + 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 Apr 1.00 12 0.23 -18 49.9 0.435 1.421 162.6 12.7 180 216 2.00 11 57.24 -19 47.4 0.439 1.422 161.3 12.7 177 216 3.00 11 54.28 -20 43.4 0.442 1.423 159.9 12.8 173 217 4.00 11 51.36 -21 38.0 0.446 1.424 158.5 12.8 169 217 5.00 11 48.48 -22 31.1 0.450 1.425 157.1 12.8 164 217 6.00 11 45.65 -23 22.5 0.454 1.427 155.8 12.8 160 217 7.00 11 42.86 -24 12.4 0.459 1.428 154.4 12.9 155 218 8.00 11 40.13 -25 0.6 0.464 1.430 153.0 12.9 150 218 9.00 11 37.46 -25 47.2 0.469 1.432 151.7 12.9 145 218 10.00 11 34.86 -26 32.2 0.474 1.433 150.4 12.9 140 218 11.00 11 32.32 -27 15.6 0.480 1.435 149.1 13.0 135 218 12.00 11 29.86 -27 57.3 0.486 1.437 147.8 13.0 130 218 13.00 11 27.47 -28 37.5 0.492 1.439 146.6 13.0 125 218 14.00 11 25.17 -29 16.1 0.498 1.441 145.3 13.1 120 218 15.00 11 22.94 -29 53.2 0.505 1.443 144.1 13.1 116 218 16.00 11 20.80 -30 28.8 0.512 1.445 143.0 13.1 111 218 17.00 11 18.75 -31 3.1 0.519 1.448 141.8 13.2 106 218 18.00 11 16.78 -31 35.9 0.526 1.450 140.7 13.2 101 217 19.00 11 14.90 -32 7.4 0.533 1.452 139.6 13.3 97 217 20.00 11 13.12 -32 37.6 0.541 1.455 138.6 13.3 92 217 21.00 11 11.42 -33 6.6 0.548 1.457 137.6 13.3 88 216 22.00 11 9.82 -33 34.4 0.556 1.460 136.6 13.4 84 216 23.00 11 8.30 -34 1.1 0.564 1.463 135.6 13.4 80 215 24.00 11 6.88 -34 26.7 0.572 1.465 134.6 13.4 76 214 25.00 11 5.55 -34 51.3 0.580 1.468 133.7 13.5 72 213 26.00 11 4.31 -35 14.9 0.589 1.471 132.8 13.5 69 212 27.00 11 3.15 -35 37.5 0.597 1.474 131.9 13.6 65 211 28.00 11 2.09 -35 59.3 0.606 1.477 131.1 13.6 62 210 29.00 11 1.11 -36 20.2 0.614 1.480 130.3 13.6 59 209 30.00 11 0.22 -36 40.4 0.623 1.483 129.5 13.7 56 207 PERIODIC COMET GIACOBINI-ZINNER (1991m) K. J. Meech, Institute for Astronomy, University of Hawaii; and W. Weller, Cerro Tololo Interamerican Observatory, report the recovery of this comet. It appeared stellar with a Mould r magnitude near 22. The indicated correction to the prediction on MPC 14592 is Delta(T) = -0.01 day. 1991 UT R.A. (1950) Decl. Observer Feb. 16.53353 15 45 02.08 - 3 48 44.2 Meech 16.59861 15 45 03.66 - 3 48 24.7 " Mar. 14.38655 15 51 29.11 - 1 06 39.4 Weller 15.36367 15 51 31.10 - 0 59 06.9 " IAUC 5225 Guy M Hurst