------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 2484 2008 Sep 11 18.00UT 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 Backup: gmh@wdcc1.bnsc.rl.ac.uk WORLD WIDE WEB http://www.theastronomer.org ------------------------------------------------------------------- COMET P/2008 R6 (GIACOBINI) AND D/1896 R2 A comet has been discovered by Koichi Itagaki and Hiroshi Kaneda of Japan on unfiltered CCD patrol frames taken on Sept. 10.56 UT using a 0.21-m f/3 reflector. The position below and reported on IAUC 8975 was measured from a confirming unfiltered CCD image taken subsequently with a 0.60-m f/5.7 reflector at Yamagata. The comet is diffuse with strong condensation, with a coma diameter of about 25" and a 2' tail toward the east-southeast. 2008 UT R.A. (2000) Decl. Mag. Sept.10.56854 20 39 18.70 - 1 17 39.9 13.5 M. Meyer, Germany, suggests that this comet is identical to comet D/1896 R2 (Giacobini), which has not been seen since Jan. 1897 and for which a prediction by Nakano gives T = 2008 Sept. 9.89 TT. The identity has been confirmed by Nakano, who notes that the comet has made 17 revolutions and passed only 0.51 AU from the earth on 1962 Sept. 9 and 0.81 AU from Jupiter on 1992 Jan. 14. The following linked orbital elements by Brian Marsden and noted on M.P.E.C. 2008-R60 are from 93 observations, 1896-2008 (including newly reduced astrometry by G. V. Williams from 1896-1897): P/1896 R2 = 2008 R6 (Giacobini) Epoch 1896 Nov. 17.0 TT = JDT 2413880.5 T 1896 Oct. 28.56025 TT MPC q 1.4546957 (2000.0) P Q n 0.14823335 Peri. 140.52573 +0.90621922 +0.41976869 a 3.5359444 Node 194.89912 -0.42031476 +0.88141947 e 0.5885977 Incl. 11.35109 -0.04585010 +0.21655014 P 6.65 Epoch 2008 Sept. 11.0 TT = JDT 2454720.5 T 2008 Sept. 10.20628 TT MPC q 1.5278701 (2000.0) P Q n 0.14797635 Peri. 154.30508 +0.89837757 +0.43922067 a 3.5400373 Node 179.62748 -0.43459779 +0.88947445 e 0.5684028 Incl. 15.31768 -0.06358070 +0.12617608 P 6.66 Ephemeris: P/2008 R6 (Giacobini) Date TT R. A. (2000) Decl. Delta r Elong. Phase m1 2008 09 01 20 28.76 +02 43.5 0.590 1.531 145.1 22.2 13.7 2008 09 11 20 39.87 -01 28.2 0.611 1.528 140.5 24.8 13.8 2008 09 21 20 54.74 -05 23.8 0.647 1.532 135.1 27.5 13.9 2008 10 01 21 12.76 -08 42.5 0.699 1.543 129.5 30.0 14.1 2008 10 11 21 33.19 -11 11.9 0.766 1.561 124.0 32.0 14.4 2008 10 21 21 55.14 -12 49.3 0.846 1.586 118.7 33.4 14.6 2008 10 31 22 17.83 -13 37.8 0.939 1.617 113.5 34.3 15.0 2008 11 10 22 40.74 -13 43.5 1.044 1.653 108.6 34.6 15.3 2008 11 20 23 03.43 -13 14.5 1.159 1.694 103.9 34.5 15.6 2008 11 30 23 25.69 -12 18.1 1.284 1.739 99.1 34.1 15.9 2008 12 10 23 47.44 -11 01.0 1.417 1.788 94.5 33.3 16.3 2008 12 20 00 08.62 -09 29.5 1.558 1.840 89.8 32.3 16.6 2008 12 30 00 29.27 -07 48.1 1.705 1.894 85.1 31.1 16.9 Guy M Hurst