Circular No. 7292

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)

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COMET C/1999 U2 (SOHO)

D. A. Biesecker, SM&A Corporation and Goddard Space Flight Center, reports observations of a comet (not a Kreutz sungrazer) discovered independently by S. Gregory (Stanford University) and by J. D. Shanklin (Comet Section, British Astronomical Association) in SOHO/LASCO C3 data. The comet is very faint, and not visible in very many frames. Astrometry and orbital computations are given on MPEC 1999-U29.

1999 UT  α_{2000}  δ_{2000}
Oct. 25.221  13^{h}46.^{m}7  −10^{o}29′

COMET C/1999 J3 (LINEAR)

Ephemeris extension to IAUC 7270 (elements MPC 36212):

1999/2000 α_{2000}  δ_{2000}  Δ  r  ϵ  β  m_{1}
Oct. 29  6^{h}37.^{m}48 −55^{o}45.^{′}8 0.611 1.181 91.^{o}7 57.^{o}2  8.5
Nov. 3  5 56.23 −65 12.9 0.706 1.229 91.2 53.8  9.1
8  4 59.6 −71 14.3 0.816 1.280 89.7 50.7  9.7
13  3 50.9 −74 23.2 0.936 1.334 87.6 47.9 10.2
18  2 43.0 −75 21.2 1.061 1.389 85.3 45.2 10.8
23  1 48.5 −74 58.3 1.187 1.446 82.8 42.7 11.3
28  1 09.9 −73 56.1 1.313 1.504 80.3 40.3 11.8
Dec. 3  0 44.3 −72 39.2 1.438 1.563 77.9 38.1 12.2
8  0 27.7 −71 19.5 1.560 1.623 75.5 36.0 12.6
13  0 17.4 −70 02.4 1.680 1.684 73.2 34.0 13.0
18  0 11.33 −68 50.1 1.797 1.745 71.0 32.2 13.4
23  0 08.34 −67 43.2 1.909 1.806 68.9 30.5 13.8
28  0 07.58 −66 41.7 2.018 1.867 67.0 29.0 14.1
Jan. 2  0 08.52 −65 45.3 2.123 1.929 65.2 27.6 14.4
7  0 10.79 −64 53.8 2.223 1.990 63.6 26.3 14.7
12  0 14.11 −64 07.0 2.318 2.052 62.1 25.1 15.0
17  0 18.28 −63 24.6 2.409 2.113 60.9 24.0 15.3
22  0 23.15 −62 46.3 2.495 2.174 59.8 23.0 15.5
27  0 28.62 −62 12.0 2.577 2.235 59.0 22.2 15.8

Visual m_{1} and coma-diameter estimates: Oct. 11.51 UT, 6.9, 16′ (R. Keen, Mt. Thorodin, CO, 7×50 binoculars); 17.13, 7.2, 10′ (K. Hornoch, Lelekovice, Czech Republic, 10×80 binoculars); 20.83, 8.0, 7′.4 (A. Pearce, Nedlands, W. Australia, 20×80 binoculars).

1999 October 28  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1999 CBAT  Daniel W. E. Green