Circular No. 6630

Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION

Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.

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COMET C/1997 G2 (MONTANI)

The following additional precise positions have been reported:

1997 UT α_{2000} δ_{2000} m_{1} Observer
Apr. 14.45040 15^{h}59^{m}05.^{s}10 −8^{o}04′47′′.9 18.6 Scotti
14.46004 15 59 04.71 −8 04 50.0  _{”}
15.69447 15 58 13.18 −8 09 33.6  Yamanishi
15.70107 15 58 12.93 −8 09 34.3  _{”}
15.70801 15 58 12.59 −8 09 36.4  _{”}
15.75332 15 58 10.73 −8 09 47.5 18.1 Chen
15.75766 15 58 10.52 −8 09 48.6  _{”}
15.76199 15 58 10.35 −8 09 48.6  _{”}
15.76632 15 58 10.17 −8 09 50.5  _{”}
16.64205 15 57 32.52 −8 13 14.0 18.8 Sugie
16.64552 15 57 32.39 −8 13 15.2  _{”}
16.64899 15 57 32.26 −8 13 14.9  _{”}

J. Scotti (Kitt Peak). 0.9-m Spacewatch telescope + CCD. m_{2} = 20.6. M. Yamanishi, A. Miyamoto, M. Aimoto, and T. Oribe (Saji Observatory).

1.03-m f/4.2 reflector + CCD. Comet diffuse; coma diameter ∼ 10′′. R. Chen and Y. J. Chen (Xinglong Station, Beijing Astronomical Obs.). A. Sugie (Dynic Astronomical Observatory). 0.60-m f/5.0 reflector + CCD.

Preliminary parabolic orbital elements by S. Nakano, Sumoto, Japan, from 21 observations, Apr. 12–16:

T = 1998 Apr. 16.215 TT  ω = 239.^{o}417
Ω = 55.787 }2000.0
q = 3.10647 AU  i = 70.037
1997TT α_{2000}  δ_{2000}  Δ  r  ϵ  β  m_{1}
Apr. 12 16^{h}00.^{m}72 − 7^{o}55.^{′}6 3.826 4.646 140.^{o}7 7.^{o}8 18.1
17 15 57.28 − 8 14.6 3.746 4.614 146.2 7.0 18.0
22 15 53.44 − 8 34.8 3.672 4.581 151.7 6.0 17.9
27 15 49.23 − 8 56.1 3.605 4.549 157.1 4.9 17.9
May 2 15 44.68 − 9 18.7 3.546 4.517 162.4 3.9 17.8
7 15 39.85 − 9 42.5 3.495 4.485 167.3 2.8 17.7
12 15 34.78 −10 07.6 3.453 4.453 170.8 2.1 17.7
17 15 29.54 −10 33.9 3.420 4.422 171.2 2.0 17.6
22 15 24.22 −11 01.5 3.395 4.390 168.0 2.7 17.6
1997 April 17  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1997 CBAT  Daniel W. E. Green