THE ASTRONOMER Electronic Circular No 424 1990 June 23 20.05UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP, England. Telephone: (0256)471074 Int:+44256471074 Telex: 94082518 Answerback: TAGUY Microlink: MAG60138 JANET:GMH @ UK.AC.CAM.ASTRONOMY.STARLINK or GUYH@UK.AC.SUSSEX.CLUSTER --------------------------------------------------------------------- PERIODIC COMET HONDA-MRKOS-PAJDUSAKOVA (1990f) J. V. Scotti reports his recovery of this comet with the 0.91-m Spacewatch telescope at Kitt Peak, as given below. The images are very slightly diffuse, of diameter about 5"-6". 1990 UT R.A. (1950) Decl. m1 June 17.41532 22 24 08.59 -13 46 48.4 19.5 18.44913 22 26 45.54 -13 38 10.7 The following orbital elements by B. G. Marsden, Center for Astrophysics, are from 31 observations 1974-1990 (mean residual 1".1), with nongravitational parameters A1 = -0.40 +/- 0.12, A2 = -0.0495 +/- 0.0002: Epoch = 1990 Sept.26.0 ET T = 1990 Sept.12.6864 ET Peri. = 325.7020 e = 0.821936 Node = 88.7097 1950.0 q = 0.541120 AU Incl. = 4.2224 a = 3.038913 AU n = 0.1860487 P = 5.298 years 1990 ET R.A. (1950) Decl. Delta r m1 June 23 22 39.12 -12 57.1 28 22 54.69 -12 04.9 0.699 1.458 16.5 July 3 23 13.16 -11 01.2 8 23 35.80 - 9 39.9 0.528 1.324 15.1 13 0 04.44 - 7 51.4 18 0 41.65 - 5 21.2 0.385 1.187 13.4 23 1 30.40 - 1 52.9 28 2 32.27 + 2 37.0 0.298 1.046 11.8 Aug. 2 3 43.54 + 7 29.9 7 4 54.08 +11 33.1 0.310 0.904 10.6 12 5 54.62 +14 08.3 17 6 42.75 +15 29.9 0.416 0.766 9.8 IAUC 5035 COMET McNAUGHT-HUGHES (1990g) Robert H. McNaught reports his discovery of a comet on a U.K. Schmidt Telescope R plate taken by Shaun M. Hughes at Siding Spring, as indicated below. The discovery plate, which had cloud interfer- ence at the end of the exposure, shows a moderately condensed 5" coma. The June 20 exposure was by McNaught with the Uppsala Southern Schmidt telescope. 1990 UT R.A. (1950) Decl. m1 June 19.55397 17 38 50.97 -65 32 04.5 17 19.59078 17 38 42.06 -65 31 49.8 20.61933 17 33 45.04 -65 23 29.6 (Our congratulations to Rob, as one of our TA Group) TA INDEX We are delighted to welcome back John Isles in Cyprus who can now be contacted via FAX: Those on MICROLINK should type 'c' at the command option and then the following at 'to:' John Isles (AC:003,TLX:5323166,ANS:CYFAX) (RECEIPT) Carlos Amengual in Spain now has a new mailbox. Those on JANET can contact him using 'MAIL' with the following address: CBS%UKC::ES.SICYD::CAM Guy M Hurst