Circular No. 7085

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) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)

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

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

COMET C/1999 A1 (TILBROOK)

Further precise CCD positions have been reported:

1999 UT α_{2000} δ_{2000} m_{2} Observer
Jan. 14.00713 23^{h}39^{m}32.^{s}00 −30^{o}28′09′′.7  Griffin
14.00940 23 39 32.42 −30 28 23.4  _{”}
14.01116 23 39 32.44 −30 28 28.9  _{”}
14.43183 23 39 50.53 −31 00 33.6 16.5 Garradd
14.43264 23 39 50.59 −31 00 37.6 16.8  _{”}
14.43517 23 39 50.67 −31 00 49.0 16.3  _{”}
14.43851 23 39 50.84 −31 01 03.2 16.6  _{”}
14.44021 23 39 50.87 −31 01 11.4 16.5  _{”}
14.44119 23 39 50.94 −31 01 15.9 16.6  _{”}
14.44171 23 39 50.94 −31 01 18.0 16.3  _{”}
14.46525 23 39 51.99 −31 03 05.1  Zoltowski
14.46944 23 39 52.20 −31 03 23.9  _{”}
14.47297 23 39 52.34 −31 03 40.2  _{”}
14.47664 23 39 52.50 −31 03 56.2 13.0  _{”}

I. P. Griffin (Cocoa). 0.3-m f/5 reflector. m_{1} = 13.5. G. J. Garradd (Loomberah). 0.45-m f/5.4 reflector. F. B. Zoltowski (Woomera). 0.30-m f/3.3 Schmidt-Cassegrain.

Parabolic orbital elements from 22 observations Jan. 13–14:

T = 1999 Jan. 29.395 TT  ω = 232.^{o}353
Ω = 258.239 }2000.0
q = 0.73341 AU  i = 88.884
1999 TT α_{2000}  δ_{2000}  Δ  r  ϵ  β  m_{1}
Jan. 12 23^{h}37.^{m}75 −27^{o}39.^{′}4 0.581 0.811 55.^{o}5 88.^{o}3  9.9
17 23 41.27 −33 58.8 0.694 0.774 51.5 84.0 10.1
22 23 41.89 −38 31.8 0.807 0.748 48.1 78.4 10.3
27 23 40.01 −41 54.8 0.916 0.735 45.3 72.3 10.5
Feb. 1 23 36.09 −44 28.2 1.018 0.735 43.0 66.1 10.7
6 23 30.65 −46 24.1 1.111 0.749 41.3 60.4 11.0
11 23 24.24 −47 51.0 1.193 0.775 40.3 55.4 11.3
16 23 17.36 −48 55.7 1.263 0.813 40.0 51.4 11.6
21 23 10.35 −49 44.2 1.321 0.859 40.6 48.5 11.9
26 23 03.43 −50 21.5 1.368 0.913 41.8 46.3 12.3
Mar. 3 22 56.68 −50 51.8 1.403 0.971 43.8 44.9 12.6

1999 January 14  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1999 CBAT  Brian G. Marsden