THE ASTRONOMER Electronic Circular No 564 1991 Sept 21 14.30UT 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 ------------------------------------------------------------------- V635 CAS Gary Poyner, Birmingham, reports that this optical component of an x-ray source is again brightening (cf E514): 1991 Aug 4.00UT, 15.2; 9.06, 15.3; 12.04, 15.2; 18.01, 15.3; 18.99, 15.3; 20.05, 15.2; 30.97, 15.2; Sept 7.04, 14.9; 7.97, 15.1; 17.01, 14.8. COMET SPACEWATCH (1991x) J. V. Scotti, Lunar and Planetary Laboratory, has measured the following positions of a comet discovered by T. Gehrels with the 0.91-m Spacewatch telescope on Kitt Peak. On the final image the condensation is essentially stellar, and there is a tail extending more than 5' in p.a. 258 deg. 1991 UT R.A. (1950) Decl. m2 Sept. 8.26146 23 14 25.94 - 8 45 13.0 8.28191 23 14 24.87 - 8 45 23.9 21.1 8.30510 23 14 23.57 - 8 45 35.2 8.32431 23 14 22.64 - 8 45 45.9 8.34513 23 14 21.49 - 8 45 56.9 8.36135 23 14 20.60 - 8 46 05.6 21.0 9.27110 23 13 33.30 - 8 54 03.4 9.27780 23 13 33.01 - 8 54 07.9 20.9 9.28718 23 13 32.52 - 8 54 13.1 IAUC 5341 P/COMET CHERNYKH (1991o) SPLIT J. Luu, Harvard-Smithsonian Center for Astrophysics; and D.Jewitt, Institute for Astronomy, University of Hawaii, communicate: "We have discovered that P/Chernykh has split. Observations with the 2.4-m telescope of the Michigan-Dartmouth-MIT Observatory on Sept. 15 and 16 show that the secondary nucleus is separated from the primary by 56".6 +/- 0".7 in p.a. 71 +/- 1 deg. Both primary and secondary objects appear extended. The Mould R magnitudes of the primary and secondary are 16.1 and 19.1, respectively, measured within an 11".7-diameter diaphragm. Neither the separation nor the difference in magnitudes changed between nights." IAUC 5347 SATELLITES OF SATURN AND NEPTUNE The IAU Executive Committee has approved the following new designations and names: Saturn XVIII Pan = 1981 S13 Neptune III Naiad = 1989 N6 Neptune IV Thalassa = 1989 N5 Neptune V Despina = 1989 N3 Neptune VI Galatea = 1989 N4 Neptune VII Larissa = 1989 N2 Neptune VIII Proteus = 1989 N1 The satellites of Neptune are numbered in order of increasing distance from the primary. IAUC 5347 Guy M Hurst