Circular No. 7648

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/2001 M1 (HELIN) M. Busch, A. Seib, F. Hormuth, and R. Stoss, Starkenburg-Sternwarte,

Heppenheim; and A. Gnädig and A. Doppler, Archenhold-Sternwarte, Berlin, report the recovery of P/1987 Q3 (= 1987w = 1987 XVII) on CCD images taken by Busch, Seib, and Hormuth with the EOCA 1.52-m reflector at Calar Alto, with the astrometry given below (measurements by Stoss, Gnädig, and Doppler). The indicated correction to the prediction by B. G. Marsden on MPC 31664 (ephemeris on MPC 42160) is ΔT = −1.0 day.

2001 UT  α_{2000}  δ_{2000}  m_{1}
June 20.14176  23^{h}35^{m}15.^{s}00  −3^{o}23′01′′.7  20
20.14339  23 35 15.09  −3 23 01.1
21.12868  23 36 16.86  −3 18 16.9
21.13032  23 36 17.01  −3 18 15.6
21.13365  23 36 17.21  −3 18 14.9

The following new orbital elements by Marsden are from 28 observations, 1987–2001 (mean residual 0′′.7):

Epoch = 2001 Sept. 8.0 TT

T = 2001 Sept.23.7154 TT  ω = 215.^{o}4212
e = 0.565600  Ω = 143.5365 }2000.0
q = 2.530770 AU  i = 4.7171

a = 5.825893 AU n^{o} = 0.0700907 P = 14.062 years

2001 TT α_{2000}  δ_{2000}  Δ  r  ϵ  β  m_{1}
June 20 23^{h}35.^{m}10 − 3^{o}23.^{′}7 2.343 2.646 95.^{o}8 22.^{o}5 18.2
30 23 44.99 − 2 39.9 2.205 2.624 102.8 22.2 18.0
July 10 23 53.50 − 2 07.2 2.073 2.604 110.1 21.5 17.8
20 0 00.38 − 1 47.4 1.949 2.586 118.0 20.3 17.6
30 0 05.40 − 1 42.0 1.836 2.571 126.3 18.6 17.5
Aug. 9 0 08.40 − 1 51.9 1.736 2.558 135.2 16.2 17.3
19 0 09.26 − 2 17.0 1.653 2.547 144.7 13.3 17.2
29 0 08.08 − 2 55.5 1.589 2.539 154.8  9.7 17.1
Sept. 8 0 05.17 − 3 43.6 1.547 2.534 165.2  5.8 17.0
18 0 01.10 − 4 35.9 1.529 2.531 174.6  2.2 17.0
28 23 56.65 − 5 25.7 1.537 2.531 170.9  3.6 17.0
Oct. 8 23 52.70 − 6 06.2 1.569 2.533 160.5  7.6 17.0
18 23 49.98 − 6 32.7 1.626 2.538 150.0 11.3 17.1
2001 June 21  \begin{matrix}c \\ ◯ \end{matrix} Copyright 2001 CBAT  Daniel W. E. Green