Circular No. 6712

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)

        URL http://cfa-www.harvard.edu/cfa/ps/cbat.html

Phone 617-495-7244/7440/7444 (for emergency use only)

COMET C/1997 O1 (TILBROOK)

Ephemeris extension to IAUC 6707 (elements on MPEC 1997-P03):

1997 TT α_{2000} δ_{2000} Δ r ϵ β m_{1}
Aug. 5 12^{h}45.^{m}71 − 8^{o}59.^{′}2 1.582 1.413 61.^{o}4 39.^{o}1 10.0
10 12 53.87 − 6 17.3 1.696 1.432 57.4 36.6 10.2
15 13 01.40 − 3 58.2 1.809 1.454 53.5 34.0 10.4
20 13 08.45 − 1 57.3 1.918 1.480 49.6 31.4 10.6
25 13 15.13 − 0 11.2 2.024 1.508 46.0 28.8 10.8
30 13 21.54 + 1 23.0 2.125 1.539 42.4 26.3 11.0
Sept. 4 13 27.74 + 2 47.6 2.221 1.572 39.1 23.8 11.2
9 13 33.79 + 4 04.6 2.312 1.608 35.9 21.5 11.4
14 13 39.73 + 5 15.6 2.396 1.645 32.9 19.4 11.6
19 13 45.57 + 6 21.8 2.475 1.685 30.2 17.5 11.7

Visual m_{1} estimates: July 25.35 UT, 9.4 (D. A. J. Seargent, The Entrance, N.S.W., 25×100 binoculars); 26.42, 10.3 (J. Tilbrook, Clare, S. Australia, 0.20-m reflector); 27.47, 10.3 (A. Pearce, Subiaco, W. Australia, 0.2-m reflector); 29.40, 9.5 (Seargent; coma diameter 5′); 31.36, 9.9 (Seargent); Aug. 1.39, 10.0 (Seargent).

COMET C/1995 O1 (HALE-BOPP)

Ephemeris extension to IAUC 6671 (elements on MPC 29568):

1997 TT α_{2000} δ_{2000} Δ r ϵ β m_{1}
Aug. 20 7^{h}39.^{m}50 −20^{o}12.^{′}9 2.961 2.389 47.^{o}1 18.^{o}1 4.1
30 7 48.41 −24 10.8 2.999 2.512 52.3 18.5 4.4
Sept. 9 7 56.16 −28 15.0 3.034 2.633 57.5 18.8 4.6
19 8 02.54 −32 24.7 3.066 2.753 62.6 18.9 4.8
29 8 07.28 −36 38.2 3.099 2.872 67.6 18.8 5.0
Oct. 9 8 10.01 −40 52.9 3.135 2.989 72.4 18.6 5.2
19 8 10.28 −45 04.8 3.177 3.105 76.8 18.2 5.4
29 8 07.56 −49 09.2 3.225 3.220 80.8 17.7 5.6
Nov. 8 8 01.18 −52 59.9 3.281 3.333 84.4 17.2 5.8
18 7 50.50 −56 29.3 3.348 3.445 87.3 16.7 6.0
28 7 35.07 −59 29.5 3.424 3.556 89.6 16.1 6.2
Dec. 8 7 14.89 −61 51.9 3.511 3.666 91.2 15.6 6.4
18 6 50.92 −63 29.5 3.609 3.775 92.1 15.1 6.6
28 6 25.11 −64 19.3 3.716 3.883 92.4 14.7 6.7
1997 August 7  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1997 CBAT  Daniel W. E. Green