------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2638 2010 Apr 19 18.36UT 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 Backup: gmh@wdcc1.bnsc.rl.ac.uk WORLD WIDE WEB http://www.theastronomer.org ------------------------------------------------------------------- COMET P/2010 H2 Brian Marsden relays on CBET 2249 that observations of an unusually bright asteroidal object only 15 deg from opposition, were reported to the Minor Planet Center by J. Vales, observing with the 0.60-m f/3.3 Deltagraph at Crni Vrh, Slovenia. The numerous follow-up observations reported after the discovery was announced on NEOCP made it clear that the object was some 2.0-2.5 AU from the earth and therefore of absolute magnitude H = 8-9. R. A. Kowalski has confirmed that it was not present to mag V = 20 in frames of the relevant region obtained by the Catalina Sky Survey as recently as Apr. 15.4 UT suggesting some sort of major outburst. 2010 UT R.A. (2000) Decl. Mag. Observer Apr. 16.00831 13 39 25.17 +04 45 49.5 12.6 Vales Orbital elements from M.P.E.C. 2010-H26 of today: T 2010 Apr. 24.769 TT MPC q 3.09157 (2000.0) P Q n 0.129844 Peri. 139.162 -0.898507 +0.379264 a 3.86239 Node 64.420 -0.438684 -0.757986 e 0.19957 Incl. 14.183 -0.015556 -0.530676 P 7.59 Ephemeris: Date TT R. A. (2000) Decl. Delta r Elong. Phase m1 2010 04 14 13 40.93 +04 44.1 2.110 3.092 165.7 4.6 12.5 2010 04 24 13 33.48 +04 47.7 2.124 3.092 160.8 6.1 12.5 2010 05 04 13 26.62 +04 37.4 2.165 3.092 152.1 8.8 12.6 2010 05 14 13 21.00 +04 12.6 2.229 3.093 142.5 11.5 12.6 2010 05 24 13 17.08 +03 33.6 2.315 3.094 132.8 13.9 12.7 2010 06 03 13 15.10 +02 42.0 2.418 3.096 123.5 15.8 12.8 2010 06 13 13 15.11 +01 39.7 2.535 3.099 114.6 17.3 12.9 2010 06 23 13 17.07 +00 28.6 2.662 3.102 106.1 18.3 13.0 Peter Birtwhistle, Great Shefford, England, writes on CBET 2253 that observations using a 0.40-m f/6.0 Schmidt-Cassegrain and identical exposures and measurement settings indicate an increase in coma size from 26" by 24" on Apr.17.1 UT to 38" by 34" on Apr. 18.1. K. Hornoch, from co-added R-band frames with the 0.65-m telescope at Ondrejov on Apr. 18.0, noted a very strongly condensed elliptical coma of 65" by 50", with the long axis in p.a. 55-235 deg. A. Novichonok and D. Chestnov, observing remotely at Cloudcroft, NM (0.18-m f/2.8 Newtonian reflector), on Apr. 19.3, described an extended 1'.0 by 0'.8 coma of integrated magnitude V = 11.4. Guy M Hurst