------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 1317 1998 Jul 06 21.06UT 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/1998 M4 (LINEAR) F. B. Zoltowski, Woomera; and P. J. Shelus, McDonald Observatory, have independently reported that another LINEAR discovery, entered on the Minor Planet Center's NEO Confirmation Page, is a comet. CCD astrometry, that by W. Offutt in response to the Central Bureau's request: 1998 UT R.A. (2000) Decl. m1 Observer June 25.34676 19 46 02.51 -10 04 50.6 17.5 Blythe 25.42039 19 45 50.99 -10 05 46.7 " 26.60160 19 42 49.13 -10 20 22.3 14.7 Zoltowski 26.62300 19 42 45.83 -10 20 38.3 14.8 " 26.89961 19 42 03.12 -10 24 08.3 16.4 Casulli 26.91956 19 41 59.94 -10 24 23.6 Tesi 26.92338 19 41 59.32 -10 24 27.0 " 26.92723 19 41 58.78 -10 24 28.4 Casulli 27.02288 19 41 43.99 -10 25 42.0 17.2 Mallia 27.02634 19 41 43.55 -10 25 41.8 16.5 " 27.22651 19 41 12.43 -10 28 14.2 16.6 Offutt 27.24335 19 41 09.77 -10 28 24.6 16.7 " 27.33895 19 40 54.82 -10 29 35.7 Bell 27.34928 19 40 53.14 -10 29 44.6 " 27.36581 19 40 50.60 -10 29 56.6 Shelus 27.37229 19 40 49.57 -10 30 01.5 " 27.59352 19 40 15.38 -10 32 43.2 14.7 Zoltowski 27.61536 19 40 11.94 -10 32 59.8 14.7 " M. Blythe, F. Shelly and M. Bezpalko (Socorro). 1-m f/2.15 reflector. Measurers J. Stuart, H. Viggh and R. Sayer. F. B. Zoltowski (Woomera). 0.30-m f/3.3 Schmidt-Cassegrain. Moderately diffuse coma, faint 1' tail in p.a. 45 deg (June 26). V. S. Casulli (Colleverde di Guidonia). 0.40-m f/3.2 reflector. L. Tesi, A. Boattini and M. Tombelli (San Marcello Pistoiese). 0.4-m f/5 reflector. Measurers A. Boattini, G. Forti and L. Tesi. F. Mallia, G. Masi and M. Di Soria (Campocatino). 0.80-m f/4.0 reflector. W. Offutt (Cloudcroft). 0.6-m f/7 Ritchey-Chretien. Well-defined condensation; small coma; broad, fanshaped (90-deg fan) tail with centerline at p.a. 45 deg, traced to about 30" from the nucleus. G. Bell (Eskridge). 0.45-m f/4.5 reflector. Measurer G. Hug. P. J. Shelus (Fort Davis). 0.76-m f/3.0 reflector. Some nebulosity, hint of tail extending roughly to the northeast. IAUC 6953 Orbital elements and ephemeris: T 1997 Dec 2.6440 TT w 102.02200 ) e 1.00000000 O 93.08000 ) 2000.0 q 2.4796900 A.U. i 154.36800 ) Source: IAUC 6954 Positions are geocentric m = 9.5 + 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. 1998 July 6.00 19 18.25 -12 17.0 2.367 3.370 168.7 16.6 101 252 11.00 19 5.22 -13 17.2 2.397 3.404 170.4 16.7 99 253 16.00 18 52.54 -14 14.6 2.442 3.438 166.5 16.8 95 253 21.00 18 40.40 -15 8.5 2.500 3.473 160.2 16.9 89 253 26.00 18 28.99 -15 58.6 2.571 3.508 153.2 17.0 83 253 31.00 18 18.43 -16 44.5 2.655 3.544 146.2 17.1 76 253 Guy M Hurst