Circular No. 8929

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/2006 B7 (ODAS)

G. V. Williams, Minor Planet Center, has rediscovered comet P/1998 X1 (cf. IAUC 7067) via survey astrometric data, as given below:

2006 UT α_{2000} δ_{2000} Mag. Observer
Jan. 30.45486 11^{h}20^{m}27.^{s}24 +5^{o}02′39′′.4 20.9 Spacewatch
30.47219 11 20 26.69 +5 02 42.1 21.4  _{”}
30.48950 11 20 26.16 +5 02 45.0 21.4  _{”}
Feb. 7.44799 11 15 55.54 +5 29 16.6  _{”}
7.46534 11 15 54.85 +5 29 20.3  _{”}
7.48269 11 15 54.18 +5 29 24.3  _{”}
20.29768 11 06 31.75 +6 24 05.8  _{”}
20.31493 11 06 30.88 +6 24 10.6  _{”}
20.33223 11 06 30.02 +6 24 15.7  _{”}
24.23882 11 03 19.60 +6 42 33.4 20.3  _{”}
24.25621 11 03 18.72 +6 42 38.1 21.0  _{”}
24.27359 11 03 17.86 +6 42 42.0 20.6  _{”}
Mar. 2.20153 10 58 23.36 +7 10 41.9 20.5  _{”}
2.21886 10 58 22.53 +7 10 47.2 20.4  _{”}
2.23613 10 58 21.64 +7 10 52.0 20.3  _{”}
23.27711 10 42 40.24 +8 36 51.9 21.1 Mt. Lemmon
23.28462 10 42 40.06 +8 36 53.3 20.5  _{”}
23.29206 10 42 39.67 +8 36 54.9 20.5  _{”}
23.29949 10 42 39.49 +8 36 56.3 20.3  _{”}
24.23720 10 42 05.61 +8 39 53.7 20.4  _{”}
24.24302 10 42 05.47 +8 39 54.7 21.2  _{”}
24.24891 10 42 05.14 +8 39 55.9 20.6  _{”}
24.25463 10 42 04.96 +8 39 57.2 20.1  _{”}

The indicated correction to the orbital elements on MPC 45656 is ΔT ≈ −2 days. The astrometric observations from the two apparitions do not fit together well, leaving systematic residuals of up to 5′′. The following orbital elements are from 96 observations, 1998-2006 (mean residual 0′′.69).

Epoch = 1998 July 6.0 TT

T = 1998 July 20.9212 TT  ω = 68.^{o}9151
e = 0.448078  Ω = 358.7172 }2000.0
q = 1.974415 AU  i = 1.3543

a = 3.577344 AU n^{o} = 0.1456676 P = 6.77 years

2008 March 31  \begin{matrix}c \\ ◯ \end{matrix} Copyright 2008 CBAT  Daniel W. E. Green