------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1534 2000 Jun 15 09.23UT 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 S4 (LINEAR) Tim Puckett, USA has submitted images to TA which show this comet has brightened significantly in recent weeks and displays a very condensed coma. The magnitude on his latest image of June 9 (cover, TA June) is about 8.5-9.0. Terry Moseley, Northern Ireland has also reported a magnitude of about 9 from a visual observation on 2000 June 11 (30x80B). Updated orbital elements: T 2000 July 26.1669 TT w 151.06810 ) e 0.99999390 O 83.19020 ) 2000.0 q 0.7649790 A.U. i 149.38970 ) Source: MPC 40668 Positions are geocentric The daily ephemeris is by Guy Hurst using EPH.EXE by Nick James. Clearly, for an apparent 'new' comet, the magnitudes have to be treated with caution. m = 7.5 + 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. 2000 June 15.00 2 15.01 +35 48.8 1.550 1.093 44.7 8.8 53 27 16.00 2 15.82 +36 8.4 1.517 1.080 45.4 8.7 56 27 17.00 2 16.66 +36 28.8 1.484 1.068 46.0 8.6 58 27 18.00 2 17.55 +36 50.1 1.450 1.055 46.7 8.5 61 27 19.00 2 18.48 +37 12.4 1.417 1.043 47.3 8.4 64 27 20.00 2 19.46 +37 35.8 1.383 1.031 48.0 8.3 67 27 21.00 2 20.51 +38 0.3 1.348 1.019 48.6 8.2 70 27 22.00 2 21.62 +38 26.0 1.314 1.007 49.2 8.1 74 27 23.00 2 22.80 +38 53.2 1.279 0.995 49.8 8.0 78 27 24.00 2 24.08 +39 21.8 1.244 0.983 50.3 7.9 83 28 25.00 2 25.45 +39 52.0 1.209 0.972 50.9 7.8 88 28 26.00 2 26.93 +40 24.0 1.173 0.960 51.4 7.7 93 28 27.00 2 28.55 +40 57.9 1.137 0.949 51.9 7.6 99 29 28.00 2 30.32 +41 33.9 1.101 0.938 52.4 7.4 106 29 29.00 2 32.26 +42 12.3 1.065 0.928 52.9 7.3 114 30 30.00 2 34.41 +42 53.2 1.028 0.917 53.3 7.2 122 30 2000 July 1.00 2 36.79 +43 36.9 0.992 0.907 53.7 7.1 132 31 2.00 2 39.45 +44 23.8 0.955 0.897 54.0 6.9 142 32 3.00 2 42.44 +45 14.1 0.919 0.887 54.3 6.8 154 33 4.00 2 45.82 +46 8.2 0.882 0.878 54.5 6.7 168 34 5.00 2 49.68 +47 6.6 0.846 0.869 54.7 6.5 184 35 6.00 2 54.10 +48 9.6 0.809 0.860 54.8 6.4 201 36 7.00 2 59.22 +49 17.7 0.773 0.851 54.8 6.2 221 37 8.00 3 5.20 +50 31.3 0.737 0.843 54.7 6.1 245 39 9.00 3 12.25 +51 51.0 0.701 0.835 54.5 5.9 271 41 10.00 3 20.66 +53 17.0 0.666 0.828 54.2 5.8 302 43 11.00 3 30.79 +54 49.4 0.631 0.820 53.8 5.6 337 45 12.00 3 43.14 +56 28.1 0.598 0.814 53.2 5.5 378 48 13.00 3 58.41 +58 12.0 0.565 0.807 52.4 5.3 424 52 14.00 4 17.49 +59 58.7 0.533 0.801 51.5 5.2 478 56 15.00 4 41.52 +61 44.0 0.503 0.796 50.3 5.0 538 62 Guy M Hurst