Comet C/1998 Y2 (Li)

Weidong Li, Department of Astronomy, University of California at Berkeley, reports his discovery of a comet in the course of the Lick Observatory Supernova Search (cf. IAUC 6627; with the participation of M. Papenkova, E. Halderson, M. Modjaz, T. Shefler, J. Y. King, R. R. Treffers and A. V. Filippenko). The object was found automatically by the Katzman Automatic Imaging Telescope in the field of NGC 1041, but it was immediately recognized as a comet by Li, who then used the equipment to make a deliberate confirmatory observation, as well as follow-up observations on the following night. Available CCD astrometry: 1998 UT R.A. (2000) Decl. m1 Observer Dec. 26.23575 2 40 26.37 - 5 25 56.4 16.2 Li 26.26623 2 40 26.47 - 5 25 27.3 16.1 " 27.31124 2 40 32.08 - 5 08 39.7 15.3 " 27.31584 2 40 32.12 - 5 08 34.1 15.3 " 27.32030 2 40 32.08 - 5 08 29.5 15.5 " 28.00613 2 40 37.04 - 4 57 25.8 15.0 Kowalski 28.02951 2 40 37.28 - 4 57 02.8 " 28.04815 2 40 37.20 - 4 56 43.1 " 28.13387 2 40 37.85 - 4 55 23.0 15.5 Bell 28.14006 2 40 37.87 - 4 55 17.3 " 28.16014 2 40 37.99 - 4 54 57.8 " W.-d. Li (Lick Observatory). 0.8-m KAIT. Object diffuse. R. Kowalski (Zephyrhills). 0.18-m reflector. Coma perhaps 18" across. G. Bell and G. Hug (Eksridge). 0.3-m Schmidt-Cassegrain. Parabolic orbital elements follow. The comet is likely of short period. T = 1999 Feb. 1.854 TT Peri. = 335.683 Node = 87.914 2000.0 q = 2.67161 AU Incl. = 26.412 1998/99 R. A. (2000) Decl. Delta r Elong. Phase m1 Dec. 28 2 40.61 - 4 57.5 2.091 2.698 118.1 18.7 14.9 Jan. 2 2 41.51 - 3 35.7 2.134 2.691 114.2 19.5 14.9 7 2 42.98 - 2 12.5 2.180 2.685 110.4 20.1 15.0 12 2 45.01 - 0 48.4 2.229 2.681 106.5 20.6 15.0 17 2 47.60 + 0 36.1 2.281 2.677 102.8 21.0 15.1 22 2 50.72 + 2 00.5 2.336 2.674 99.1 21.3 15.1