Circular No. 7072

Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION

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COMET C/1998 Y1 (LINEAR)

LINEAR has discovered another comet. CCD astrometry:

1998 UT α_{2000} δ_{2000} m_{1} Observer
Dec. 22.30945 7^{h}03^{m}18.^{s}04 +20^{o}18′49′′.8 18.5 Blythe
22.37792 7 03 16.45 +20 21 13.1 18.6  _{”}
23.92879 7 02 47.06 +21 16 02.1 16.7 Lehmann
23.93406 7 02 46.90 +21 16 13.6 16.5 Šarounová
23.93640 7 02 46.89 +21 16 18.2  _{”}
23.99209 7 02 45.60 +21 18 17.1 17.0 Moravec
24.00179 7 02 45.35 +21 18 37.4  _{”}
24.22660 7 02 41.22 +21 26 36.7 16.0 Offutt
24.23815 7 02 40.94 +21 27 00.7 16.4  _{”}
24.33438 7 02 38.66 +21 30 25.7  Rogers
24.34913 7 02 38.37 +21 30 56.4  _{”}

M. Blythe, F. Shelly and M. Bezpalko (Socorro). Measurers J. Stuart, H.

Viggh and R. Sayer. 1.0-m f/2.15 reflector. G. Lehmann and J. Kandler (Schönbrunn). 0.50-m f/4.0 reflector. L. Šarounová (Ondřejov). 0.65-m f/3.6 reflector. Coma ∼ 25′′ in diameter,

short and probably wide tail to northwest. m_{2} = 17.8. Z. Moravec (Kleť). 0.57-m f/5.2 reflector. Coma of diameter ∼ 10′′. W. Offutt (Cloudcroft). 0.60-m f/7 Ritchey-Chrétien. Central condensa-

tion ∼ 6′′; coma extending 8′′ north, 7′′ east, 6′′ south and 11′′ west. J. E. Rogers (Camarillo). 0.25-m Schmidt-Cassegrain.

The following parabolic orbital elements, by the undersigned, are from the selected data above. The comet is likely of short period.

T = 1998 Nov. 20.962 TT  ω = 339.^{o}790
Ω = 98.987 }2000.0
q = 1.78642 AU  i = 29.492
1998/99 α_{2000}  δ_{2000}  Δ  r  ϵ  β  m_{1}
Dec. 23 7^{h}03.^{m}08 +20^{o}43.^{′}2 0.863 1.833 166.^{o}1 7.^{o}4 16.3
28 7 01.29 +23 39.4 0.870 1.849 172.0  4.3 16.4
Jan. 2 6 59.21 +26 31.3 0.884 1.866 175.7  2.3 16.4
7 6 57.03 +29 14.7 0.906 1.885 172.6  3.9 16.5
12 6 54.95 +31 46.1 0.935 1.907 167.0  6.7 16.7
17 6 53.19 +34 03.2 0.972 1.929 161.2  9.5 16.8
22 6 51.94 +36 04.7 1.015 1.954 155.6 12.0 16.9
1998 December 24  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1998 CBAT  Brian G. Marsden