THE ASTRONOMER Electronic Circular No 581 1991 Nov 24 16.40UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England. Telephone/FAX(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 TSUCHINSHAN 1 (1991c1) S. Nakano, Sumoto, Japan, reports the recovery of this comet by T. Seki with the 0.60-m reflector at Geisei. The comet has a tail 30" long in p.a. 300 deg and is diffuse with central condensation. Seki's observations yield a correction to the prediction on MPC 13057 of Delta(T) about +0.02 day: 1991 UT R.A. (1950) Decl. m1 Nov. 8.84306 12 30 53.70 + 4 17 18.5 17 11.83056 12 38 14.92 + 3 39 39.0 18 11.84340 12 38 16.77 + 3 39 30.1 11.85208 12 38 18.09 + 3 39 19.9 IAUC 5383 The comet appears to be much fainter (m1) than predicted in the ICQ Handbook (1991). 1991 VG - A RETURNING SPACECRAFT? As I announced at the 1991 TA AGM, a report has been received from the Central Bureau mentioning discovery by J.V.Scotti of a fast- moving object on Nov 6 at V=20.7. From 24 precise positions obtained using the 0.91-m Spacewatch Telescope, Brian Marsden derived the following elements: Epoch = 1991 Oct. 31.0 ET T = 1992 Jan. 14.1186 ET Peri. = 260.8887 e = 0.065262 Node = 212.9200 1950.0 q = 0.971470 AU Incl. = 0.3913 a = 1.039297 AU n = 0.9302397 P = 1.060 years Dan Green comments on IAUC 5387 that these elements are remarkably similar to those of the earth. The minimum geocentric distance is 0.0031 AU on Dec 5.4 UT (H=28.8). Geocentric solutions yield e > 3. The object might be a returning spacecraft. The following additional information is given in view of the considerable interest shown in this object recently: Orbital elements for additional epochs (cf. IAUC 5387): Epoch = 1991 Nov. 30.0 ET T = 1992 Jan. 13.8337 ET Peri. = 293.8937 e = 0.078509 Node = 180.2000 1950.0 q = 0.966182 AU Incl. = 0.2182 a = 1.048499 AU n = 0.9180203 P = 1.074 years Epoch = 1991 Dec. 10.0 ET T = 1992 Jan. 5.7221 ET Peri. = 26.3867 e = 0.074974 Node = 78.8835 1950.0 q = 0.972669 AU Incl. = 1.5968 a = 1.051505 AU n = 0.9140861 P = 1.078 years 1991 ET R.A. (1950) Decl. Delta r V Nov 24 2 54.52 - 3 23.7 0.009 0.995 19.9 25 2 55.13 - 5 41.6 26 2 55.86 - 8 22.7 0.008 0.993 19.7 27 2 56.74 -11 33.2 28 2 57.82 -15 21.5 0.006 0.992 19.4 29 2 59.18 -19 59.8 30 3 00.99 -25 44.0 0.005 0.990 19.2 Dec. 1 3 03.52 -32 57.2 2 3 07.44 -42 08.6 0.004 0.988 19.1 3 3 14.53 -53 50.3 4 3 32.20 -68 18.7 0.003 0.986 19.5 5 5 39.1 -84 14.4 6 13 51.8 -75 58.1 0.003 0.984 21.2 Guy M Hurst