Circular No. 8599

Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION

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

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CBAT@CFA.HARVARD.EDU (science)

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COMET P/1998 W1 = P/2005 R3 (SPAHR)

This comet has been recovered on CCD images taken by F. Fratev and E. Mihaylova (Zvezdno Obshtestvo Obsevatory, Plana, 0.25-m f/4.7 reflector) and by E. J. Christensen (Catalina 0.68-m Schmidt telescope); Christensen noted a coma diameter of ≈ 15′′ on 60-s exposures through thin clouds.

2005 UT α_{2000} δ_{2000} Mag. Observer
Sept. 7.08697 7^{h}53^{m}54.^{s}28 +17^{o}37′11′′.4 17.3 Fratev
7.09583 7 53 55.62 +17 37 10.7 17.3  _{”}
7.47821 7 54 57.48 +17 37 38.2 17.2 Christensen
7.48347 7 54 58.29 +17 37 38.8 17.3  _{”}
7.48759 7 54 59.04 +17 37 38.8 17.2  _{”}
7.48935 7 54 59.29 +17 37 40.0 17.7  _{”}
7.49418 7 55 00.15 +17 37 40.0 17.2  _{”}
7.49593 7 55 00.26 +17 37 40.5 17.7  _{”}
7.49766 7 55 00.62 +17 37 39.9 17.5  _{”}
7.49942 7 55 00.87 +17 37 40.1 18.0  _{”}
10.11091 8 02 03.12 +17 40 21.7 17.3 Fratev
10.11661 8 02 03.97 +17 40 21.3 17.3  _{”}
10.12247 8 02 04.95 +17 40 22.2 17.3  _{”}
11.12051 8 04 46.07 +17 41 18.5 17.3  _{”}
11.13110 8 04 47.54 +17 41 13.9 17.3  _{”}

The indicated correction to the predictions on MPC 45657 and in the Comet Handbook 2005 is ΔT = −0.2 day. Orbital elements by B. G. Marsden, from 273 observations, 1998 Nov. 13–2005 Sept. 11 (mean residual 0′′.6).

Epoch = 1999 Jan. 22.0 TT

T = 1999 Jan. 17.9523 TT  ω = 346.^{o}6774
e = 0.510065  Ω = 101.9735 }2000.0
q = 1.725761 AU  i = 21.9615
a = 3.522428 AU  n^{o} = 0.1490874  P = 6.611 years

Epoch = 2005 Aug. 18.0 TT

T = 2005 Sept. 3.2187 TT  ω = 346.^{o}8442
e = 0.509476  Ω = 101.9200 }2000.0
q = 1.729675 AU  i = 21.9542
a = 3.526182 AU  n^{o} = 0.1488494  P = 6.622 years
2005 September 12  \begin{matrix}c \\ ◯ \end{matrix} Copyright 2005 CBAT  Daniel W. E. Green