------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1115 1996 Aug 17 10.00UT 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 ------------------------------------------------------------------- 1996 PW MPEC 1996-P03 contains observations and a preliminary orbit for an asteroidal object with a record high e. 1996 PW was identified and recognized as unusual by Gareth Williams, Minor Planet Center, Harvard-Smithsonian Center for Astrophysics, in two nights (Aug. 9 and 12) of general asteroidal data from the NEAT program, carried out under the direction of Eleanor Helin, Jet Propulsion Laboratory, using images obtained with the GEODSS tele- scope at Haleakala.More recent observations demonstrate that e > 0.99 with other elements T = 1996 Aug. 8, Peri = 182 deg, Node = 144 deg, i = 30 deg, q = 2.537 AU, H = 14.0. Imaging by D. Jewitt on Aug. 16 with the University of Hawaii's 2.2-m reflector showed the object as a point source, devoid of coma in integrations that would easily show the coma of (2060) = comet 95P/Chiron, for example. Photometry by D. Rabinowitz, Jet Propulsion Laboratory, at the Table Mountain Observatory on Aug. 14.4 UT yields V = 17.9, V-R = +0.31 +/- 0.05, V-I = +0.60 +/- 0.05 (assuming solar values V-R = +0.367, V-I = +0.705). IAUC 6452 (Extract) TA Assistant Editor comments: The ephemeris below is based on the highly preliminary elements by Brian Marsden. Errors of > 0.5 degree are quite possible bearing in mind the lack of decimal places for w, O and i. An e > 0.99 suggests a period in excess of a thousand years and an aphelion point beyond 100 AU. Current estimates place the object at around mag 17 - 18. A value of H = 14.0 for an asteroidal object of albedo 0.05 - 0.25 would suggest a diameter in the range of 4 to 9 kilometres. T 1996 Aug 8.0000 TT w 182.00000 ) e 1.00000000 (assumed) O 144.00000 ) 2000.0 q 2.5370000 A.U. i 30.00000 ) Source: IAUC 6452 Positions are geocentric m = 14.0 + 5.0 log R + 5.0 log r Date R.A. (2000) Dec. R r Elong Mag. Motion h m o ' (AU) (AU) o "/hr P.A. 1996 Aug 18.00 22 18.53 -15 21.4 1.532 2.539 172.9 16.9 48 185 19.00 22 18.42 -15 40.4 1.532 2.540 173.5 17.0 48 185 20.00 22 18.30 -15 59.4 1.532 2.540 173.9 17.0 48 185 21.00 22 18.18 -16 18.4 1.532 2.541 174.2 17.0 48 185 22.00 22 18.06 -16 37.3 1.533 2.541 174.2 17.0 47 185 23.00 22 17.93 -16 56.1 1.534 2.542 174.1 17.0 47 186 24.00 22 17.80 -17 14.8 1.536 2.543 173.7 17.0 47 186 25.00 22 17.67 -17 33.4 1.537 2.544 173.2 17.0 47 186 26.00 22 17.55 -17 51.9 1.539 2.544 172.5 17.0 46 186 27.00 22 17.42 -18 10.3 1.541 2.545 171.7 17.0 46 186 28.00 22 17.29 -18 28.5 1.544 2.546 170.9 17.0 46 186 29.00 22 17.17 -18 46.6 1.547 2.547 170.0 17.0 45 186 30.00 22 17.04 -19 4.5 1.550 2.548 169.0 17.0 45 185 31.00 22 16.92 -19 22.3 1.553 2.549 168.0 17.0 44 185 Martin Mobberley