Circular No. 6928

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 K6 (SHOEMAKER-LEVY 2) C. W. Hergenrother reports his recovery of comet P/1990 UL_{3} (=

1990p = 1990 XVI) with the Smithsonian Astrophysical Observatory’s 1.2m reflector at Mt. Hopkins. The comet appears stellar, although the observations were made through moderate cirrus. The indicated correction to the prediction by S. Nakano on MPC 29881 is ΔT = −0.5 day.

1998 UT  α_{2000}  δ_{2000}  m_{2}
May 19.35584  16^{h}17^{m}28.^{s}53  −20^{o}20′43′′.7  21.0
19.35971  16 17 28.37  −20 20 42.8  21.0
19.36359  16 17 28.21  −20 20 42.7  21.0
20.32096  16 16 50.24  −20 18 41.0  21.0
20.32483  16 16 50.13  −20 18 40.4  21.3
20.32869  16 16 49.98  −20 18 39.8  21.5

The following improved orbital elements, by the undersigned, satisfy 27 observations 1990–1998 with mean residual 0′′.7:

Epoch = 2000 Feb. 26.0 TT

T = 2000 Feb. 6.0494 TT  ω = 142.^{o}0314
e = 0.579784  Ω = 234.7521 }2000.0
q = 1.868674 AU  i = 4.6570

a = 4.446936 AU n^{o} = 0.1051024 P = 9.378 years

1998 TT α_{2000} δ_{2000} Δ r ϵ β m_{2}
May 27 16^{h}12.^{m}33 −20^{o}04.^{′}1 3.794 4.807 178.^{o}7 0.^{o}3 21.4
June 6 16 05.55 −19 41.6 3.766 4.764 168.0  2.5 21.5
16 15 59.12 −19 19.5 3.768 4.720 156.9  4.8 21.7
26 15 53.44 −18 59.4 3.798 4.675 146.0  7.0 21.8
July 6 15 48.88 −18 42.6 3.851 4.630 135.4  8.9 21.9
16 15 45.67 −18 30.1 3.925 4.585 125.0 10.5 21.9
26 15 43.95 −18 22.7 4.014 4.539 115.1 11.7 22.0
Aug. 5 15 43.77 −18 20.6 4.114 4.492 105.5 12.6 22.1
15 15 45.12 −18 23.7 4.220 4.445  96.2 13.1 22.1
25 15 47.95 −18 31.6 4.328 4.397  87.3 13.3 22.2
Sept. 4 15 52.16 −18 43.6 4.435 4.349  78.6 13.1 22.2
14 15 57.66 −18 58.9 4.536 4.301  70.2 12.7 22.2
24 16 04.34 −19 16.8 4.628 4.252  62.1 12.0 22.2
Oct. 4 16 12.10 −19 36.3 4.710 4.202  54.1 11.1 22.2
1998 June 2  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1998 CBAT  Brian G. Marsden