Electronic Telegram No. 2584
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2010 X1 (ELENIN)
     Leonid Elenin (Lyubertsy, Russia) reports his discovery of a comet on
four 240-s unfiltered CCD exposures taken remotely with a 0.45-m f/2.8
astrograph at the ISON-NM observatory near Mayhill, NM, USA, on Dec. 10.435
UT (discovery observation tabulted below).  After posting on the Minor
Planet Center's "NEOCP" webpage, other cometary astrometrists have noted the
object's cometary appearance.  A. Sergeyev (Kharkov, Ukraine) and A. Novichonok
(Kondopoga, Russia) write that four stacked 300-s CCD images taken with a
1.5-m f/8 reflector at the Majdanak Observatory in Uzbekistan on Dec. 11.0 show
a teardrop-shaped, very diffuse coma of diameter 6" (total magnitude 19.1;
magnitude of nuclear condensation 20.7) and a tail of length 10"-12" in p.a.
298 deg.  W. H. Ryan obtained R-band CCD images with the Magdalena Ridge
Observatory's 2.4-m f/8.9 reflector on Dec. 12.47-12.49 that show the object
to be diffuse with a tail in p.a. about 315 deg.  R. S. McMillan, J. V. Scotti,
and M. L. Terenzoni report that five 60-s R-band images taken through thin
clouds on Dec. 12.5 with the Steward Observatory 2.3-m f/3 Bok telescope (+
90Prime CCD camera) at Kitt Peak in 2" seeing show a coma diameter of about 7"
and a tail extending 10" in p.a. 290 deg.  H. Sato (Ota-ku, Tokyo, Japan)
obtained CCD images remotely with a 0.50-m f/6.8 reflector at the RAS
Observatory near Mayhill on Dec. 12.51 that show an 8" coma and a 45" tail
toward p.a. 285 degrees.

     2010 UT             R.A. (2000) Decl.       Mag.   Observer
     Dec. 10.41707   11 58 06.29   - 0 34 20.1   19.5   Elenin

The available astrometry, the following preliminary parabolic orbital elements
by G. V. Williams, and an ephemeris appear on MPEC 2010-X101.  It is possible
that this comet is of short period.

     T = 2010 Apr.  1.810 TT          Peri. = 181.193
                                      Node  = 319.659   2000.0
     q = 5.15165 AU                   Incl. =   1.456


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2010 CBAT
2010 December 13                 (CBET 2584)              Daniel W. E. Green