Circular No. 7043

Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION

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

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COMET P/1998 U4 (SPAHR) The following additional precise CCD positions have been reported:

1998 UT α_{2000} δ_{2000} m_{1} Observer
Oct. 29.26596 4^{h}08^{m}01.^{s}96 −12^{o}10′20′′.8  Spahr
29.26990 4 08 01.82 −12 10 23.3  _{”}
29.31271 4 08 00.86 −12 10 44.9 16.6 Koff
29.46145 4 07 57.17 −12 11 59.9  Spahr
30.39319 4 07 34.62 −12 19 48.8  Balam
30.39801 4 07 34.50 −12 19 51.2  _{”}

T. B. Spahr (Catalina Sky Survey). 0.41-m f/3 Schmidt telescope. R. A. Koff (Thornton). 0.20-m f/10 Schmidt-Cassegrain telescope. D. D. Balam (Dominion Astrophysical Observatory). 1.82-m reflector.

Preliminary orbital elements by the undersigned from 13 observations, Oct. 27–30:

T = 1999 Mar. 28.753 TT  ω = 253.^{o}680
e = 0.30575  Ω = 183.978 }2000.0
q = 3.93034 AU  i = 32.605
a = 5.66127 AU n^{o} = 0.073170 P = 13.47 years
1998TT α_{2000}  δ_{2000}  Δ  r  ϵ  β  m_{1}
Oct. 24 4^{h}09.^{m}95 −11^{o}24.^{′}5 3.196 4.000 139.^{o}0 9.^{o}4 16.5
29 4 08.14 −12 08.1 3.169 3.996 141.6 8.9 16.5
Nov. 3 4 06.03 −12 49.0 3.148 3.992 143.8 8.4 16.5
8 4 03.67 −13 26.7 3.133 3.987 145.2 8.1 16.5
13 4 01.12 −14 00.7 3.125 3.984 145.9 8.0 16.5
18 3 58.43 −14 30.4 3.123 3.980 145.8 8.0 16.5
23 3 55.66 −14 55.4 3.128 3.976 144.8 8.2 16.5
28 3 52.90 −15 15.4 3.139 3.973 143.1 8.6 16.5
Dec. 3 3 50.21 −15 30.3 3.156 3.969 140.8 9.0 16.5

COMET P/1998 S1 (LINEAR-MUELLER) Visual m_{1} estimates: Oct. 20.86 UT, 14.2 (M. Lehký, Hradec Králové,

Czech Republic, 0.42-m reflector); 21.82, 14.0 (K. Hornoch, Lelekovice, Czech Rep., 0.35-m reflector); 23.91, 13.7 (Hornoch); 25.86, 14.1 (Lehký).

1998 October 31  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1998 CBAT  Daniel W. E. Green