------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1468 1999 Nov 19 07.20UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK GMH at AST.STAR.RL.AC.UK WORLD WIDE WEB http://www.demon.co.uk/astronomer ------------------------------------------------------------------- COMET C/1999 T3 (LINEAR) Linkage at the Minor Planet Center of observations by LINEAR (discovery observation below) on several nights during Oct. 3-21 revealed an object with a nearly-parabolic retrograde orbit. This orbit also represented a single-night detection of an object by E. W. Elst and S. Ipatov at Uccle on Oct. 18. Following placement of an ephemeris on The NEO Confirmation Page further observations were made on Oct. 24 and 25. In response to enquiries, Elst remarked that the object was diffuse and had a possible tail to the north; J. Ticha and M. Tichy, Klet, reported the object as slightly more diffuse than stars of comparable brightness and deduced a coma size of 9"; and D. Durig, Sewanee, TN, in poor conditions (strong wind, full moon), also noted the object's diffuse appearance. 1999 UT R.A. (2000) Decl. m2 Oct. 3.33731 3 09 03.31 +22 06 48.3 18.3 The following parabolic orbital elements appear on MPEC 1999-U27: T = 2000 Aug. 29.1385 TT Peri. = 210.9351 Node = 223.5095 2000.0 q = 5.370459 AU Incl. = 104.6325 1999 TT R. A. (2000) Decl. Delta r Elong. Phase m1 Nov. 8 2 42.77 +16 21.1 4.804 5.795 178.1 0.3 17.0 18 2 34.92 +14 33.7 4.804 5.768 165.8 2.4 17.0 28 2 27.60 +12 48.1 4.843 5.742 153.4 4.4 17.0 Dec. 8 2 21.13 +11 07.8 4.915 5.716 141.2 6.2 17.0 18 2 15.78 + 9 35.5 5.018 5.692 129.2 7.7 17.1 28 2 11.68 + 8 13.0 5.144 5.668 117.6 8.8 17.1 COMET C/1999 U3 (LINEAR) R. Huber reports the discovery by LINEAR of a comet. 1999 UT R.A. (2000) Decl. m1 Observer Oct. 30.32373 3 27 14.49 +58 17 44.3 18.5 LINEAR 30.34009 3 27 14.31 +58 17 50.7 19.1 " 30.37274 3 27 14.12 +58 18 01.6 19.6 " 30.38902 3 27 13.82 +58 18 06.5 18.6 " LINEAR (Lincoln Laboratory ETS, Socorro). Observers M. Bezpalko, M. Blythe, F. Shelly, M. Elowitz, and R. Huber. Measurers J. Stuart, H. Viggh, and R. Sayer. 1.0-m f/2.15 reflector + CCD. Short tail. IAUC 7295 Preliminary parabolic orbital elements by Dan Green: T = 1999 Sept.12.27 TT Peri. = 58.82 Node = 324.90 2000.0 q = 1.8098 AU Incl. = 20.58 Ephemeris by Guy Hurst using EPH.EXE by N.James: m = 13.5 + 5.0 log R + 10.0 log r Date R.A. (2000) Dec. R r Elong Mag. Motion h m o ' (AU) (AU) o "/hr P.A. 1999 Nov 18.00 3 22.10 +58 15.2 1.132 1.998 140.8 16.8 14 207 23.00 3 20.62 +57 44.5 1.153 2.025 142.0 16.9 19 196 28.00 3 19.56 +57 3.2 1.179 2.053 142.8 17.0 23 188 1999 Dec 3.00 3 19.07 +56 13.1 1.209 2.083 143.0 17.1 27 181 8.00 3 19.29 +55 15.7 1.245 2.114 142.7 17.2 30 175 13.00 3 20.28 +54 13.0 1.285 2.147 141.8 17.4 33 169 18.00 3 22.07 +53 6.8 1.330 2.180 140.4 17.5 35 164 23.00 3 24.64 +51 58.8 1.380 2.215 138.5 17.7 37 158 28.00 3 27.92 +50 50.3 1.435 2.250 136.2 17.8 38 153 Guy M Hurst