THE ASTRONOMER Electronic Circular No 570 1991 October 16 20.27UT 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 ------------------------------------------------------------------- EF PEGASI Patrick Schmeer, Germany, has reported a very rare outburst of this UG-type variable which is located at: RA 21h 12.7m DEC +13 52' (1950) The GCVS has the range as 10.7-[17p and mentions that the variable is component B of a double. Star A is approximately of magnitude 14.0pg and B is 5" away in positional angle 305deg. Patrick provides the following estimates: 1991 Oct 14.913UT, 13.0; 15.779, 10.9. He confirms that both components were visible in his 0.203-m SC and that he would judge star A to be about visual magnitude 13.0. In response to our e-mail alert, Gary Poyner, Birmingham, confirms the outburst: Oct 15.853UT, 10.7 class 2. USSR Circular 1043 (1979) mentions outbursts as follows: 1957 Aug 20, 11.4pg; 1962 Aug 29, 10.7pg; 1964 Oct 10, 11.2pg. In view of the duplicity, extreme care is needed with estimates and reports should state whether both stars were seen when estimates were made. A chart can be sent on e-mail request. PERIODIC COMET McNAUGHT-HUGHES (1991y) R. H. McNaught provides the following additional measurements from films taken with the Uppsala Southern Schmidt telescope at Siding Spring: 1991 UT R.A. (1950) Decl. Oct. 2.55556 23 09 09.64 -18 47 58.9 2.73611 23 09 05.38 -18 47 46.3 5.52552 23 08 06.55 -18 44 11.9 The following preliminary orbital elements, from the six available observations, indicate that this is a short-period comet: T = 1991 June 29.248 ET Peri. = 231.290 e = 0.39604 Node = 87.864 1950.0 q = 2.17255 AU Incl. = 7.304 a = 3.59718 AU n = 0.144464 P = 6.82 years 1991 ET R.A. (1950) Decl. Delta r m1 Oct. 1 23 09.79 -18 49.1 1.345 2.277 16.5 6 23 07.96 -18 43.4 11 23 06.70 -18 31.9 1.427 2.299 16.7 16 23 06.05 -18 15.0 21 23 06.04 -17 53.0 1.527 2.323 16.9 26 23 06.66 -17 26.5 31 23 07.90 -16 55.9 1.642 2.349 17.1 IAUC 5360 PERIODIC COMET SHOEMAKER-LEVY 5 (1991z) The following preliminary orbital elements, from the five available observations, indicate that this is a short-period comet: T = 1991 Dec. 1.533 ET Peri. = 0.430 e = 0.48700 Node = 30.062 1950.0 q = 1.96464 AU Incl. = 11.057 a = 3.82974 AU n = 0.131507 P = 7.49 years IAUC 5361 The comet is mag 16 and fading. Guy M Hurst