Circular No. 6940

Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION

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

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COMET 1998 M1 The Lincoln Laboratory Near-Earth Asteroid Research project has

found another comet. The following CCD observations have been reported:

1998 UT α_{2000} δ_{2000} m_{2} Observer
June 16.24366 15^{h}27^{m}08.^{s}87 −25^{o}01′51′′.9 17.5 Blythe
16.26111 15 27 08.41 −25 01 35.0 18.1  _{”}
16.27875 15 27 08.21 −25 01 27.5 18.2  _{”}
16.29655 15 27 08.13 −25 01 20.2 18.0  _{”}
16.31370 15 27 07.52 −25 01 12.1 18.0  _{”}
16.88270 15 27 00.34 −24 56 42.5 17.2 Tichý
16.88375 15 27 00.35 −24 56 42.3  _{”}
16.88480 15 27 00.35 −24 56 41.7  _{”}
16.88626 15 27 00.30 −24 56 41.7  _{”}

M. Blythe, F. Shelly, and M. Bezpalko (Lincoln Laboratory ETS). 1-m f/2.15 reflector. Measurers J. Stuart and H. Viggh. Tail 20′′ long in p.a. ∼ 220^{o}.

M. Tichý and Z. Moravec (Kleť). 0.57-m f/5.2 reflector. Measurer Tichý. Tail 20′′ long in p.a. 150^{o}; m_{1} = 15.6.

COMET C/1998 K5 (LINEAR) Ephemeris extension to IAUC 6923 (orbital elements MPC 31894):

1998TT α_{2000} δ_{2000} Δ r ϵ β m_{1}
June 16 19^{h}31.^{m}33 +37^{o}28.^{′}6 0.191 1.106 113.^{o}5 57.^{o}4 13.8
18 19 56.59 +41 37.3 0.188 1.090 108.2 62.3 13.7
20 20 25.39 +45 22.8 0.188 1.074 103.0 67.2 13.7
22 20 57.48 +48 33.7 0.190 1.060  98.0 71.8 13.6
24 21 32.08 +51 01.3 0.194 1.046  93.3 76.0 13.6
26 22 07.87 +52 41.6 0.200 1.033  89.1 79.7 13.6
28 22 43.27 +53 35.9 0.207 1.021  85.4 82.9 13.7
30 23 16.81 +53 49.9 0.216 1.010  82.2 85.6 13.7
July 2 23 47.47 +53 31.9 0.226 1.000  79.5 87.7 13.8
4 0 14.78 +52 50.7 0.238 0.992  77.2 89.3 13.8
6 0 38.73 +51 54.1 0.250 0.984  75.4 90.3 13.9

Total visual magnitude estimates: May 31.95 UT, 14.6 (M. Lehký, Hradec Králové, Czech Republic, 0.42-m reflector); June 1.00, 14.9 (K. Hornoch, Lelekovice, Czech Republic, 0.35-m reflector); 2.93, 14.3 (Lehký).

1998 June 16  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1998 CBAT  Daniel W. E. Green