Circular No. 7550

Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION

Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.

IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)

CBAT@CFA.HARVARD.EDU (science)

URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304

Phone 617-495-7440/7244/7444 (for emergency use only)

COMET C/2000 Y2

Additional CCD astrometry (cf. IAUC 7549):

2000 UT α_{2000} δ_{2000} m_{1} Observer
Dec. 28.61241 9^{h}24^{m}20.^{s}45 +0^{o}40′33′′.1  Kojima
28.63634 9 24 20.64 +0 40 29.9  _{”}
28.64643 9 24 20.74 +0 40 28.7 18.1  _{”}
28.77153 9 24 21.76 +0 40 14.6  Kadota
28.77578 9 24 21.86 +0 40 11.9  _{”}
28.77925 9 24 21.72 +0 40 11.1 17.8  _{”}
28.78692 9 24 22.11 +0 40 11.8  _{”}
28.97118 9 24 23.91 +0 39 47.3 17.1 Tichá
28.97353 9 24 23.96 +0 39 45.9  _{”}
28.97674 9 24 24.01 +0 39 45.9  _{”}
29.09772 9 24 25.05 +0 39 30.5  Kušnirak
29.16905 9 24 25.62 +0 39 22.2  _{”}
29.59097 9 24 29.82 +0 38 32.7  Kojima
29.59674 9 24 29.90 +0 38 31.6  _{”}
29.61140 9 24 30.02 +0 38 28.3 18.0  _{”}
29.62580 9 24 30.12 +0 38 27.8  _{”}

T. Kojima (Chiyoda). 0.25-m f/6.0 reflector. On Dec. 28, comet small with

strong condensation and apparent extension toward the west. K. Kadota (Ageo). 0.18-m f/5.5 reflector. Communicated by S. Nakano. J. Tichá, M. Tichý, and M. Kočer (Kleť). 0.57-m f/5.2 reflector. P. Kušnirak (Ondřejov). 0.65-m f/3.6 reflector.

Preliminary parabolic orbital elements:

T = 2001 Jan. 24.003 TT  ω = 307.^{o}213
Ω = 188.572 }2000.0
q = 2.82988 AU  i = 11.625
2000/01 α_{2000}  δ_{2000}  Δ  r  ϵ  β  m_{1}
Dec. 22 9^{h}22.^{m}81 + 0^{o}58.^{′}4 2.154 2.850 126.^{o}4 16.^{o}1 17.2
27 9 24.04 + 0 44.3 2.102 2.844 130.9 15.2 17.2
Jan. 1 9 24.80 + 0 34.3 2.054 2.840 135.4 14.1 17.1
6 9 25.11 + 0 28.6 2.011 2.836 140.1 12.9 17.0
11 9 24.99 + 0 27.5 1.972 2.833 144.8 11.5 17.0

2000 December 29  \begin{matrix}c \\ ◯ \end{matrix} Copyright 2000 CBAT  Daniel W. E. Green