Archive for December, 2010

С/2010 X1 – A Week After it’s Discovery

C/2010 X1 (Elenin), L. Elenin, ISON-NM observatory

It has been a week since the discovery of C/2010 X1 (Elenin). Exactly seven days ago at this time, I discovered a small diffuse object in the images. However even after a week, the orbit of the new comet is still not clear. This is the first object in my memory whose orbit has not been determined, even with an arc of seven days’ observations. All the observations agree well both with an orbit whose perihelion is within the orbit of the Earth and with a perihelion near Jupiter’s orbit. In the first case the comet will increase in brightness and may become a very bright object in the sky. Observations of the comet will continue until full moon, and I hope by that time we will uncover the secret of Comet Elenin.

Comet Elenin on Russian television

Possible parameters for the orbit of Comet C/2010 X1

Using the program FindOrb and its simplex method, we can make a conjecture about two variants (below) of the orbit of the new comet. In both cases the observations from the Malina River Observatory (B90) were excluded from the calculations due to their low precision.

In both cases the comet has a short period orbit, with periods of 14.9 and 53.8 years respectively.

C/2010 X1 (ELENIN) = WJ08B04

Tonight Moscow time, the circular from the Central Bureau of Astronomical Telegrams (CBAT) was released. The new comet received the designation C/2010 X1 (ELENIN). The orbit of the comet is still preliminary and it certainly will change. For that reason we will discuss that later. But now I want to say thank you to all who have congratulated us, and to thank those who helped confirm the cometary nature of the object.

Electronic Telegram No. 2584
Central Bureau for Astronomical Telegrams
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail: (alternate
Prepared using the Tamkin Foundation Computer Network

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

Object WJ08B04 – first Russian comet!

On the basis of photographs obtained with the 1.5 meter Maidanak telescope, we can say that our new object WJ08B04 is a comet. With high probability we can say that it is a long- period comet. For these important photographs, I want to thank Artem Novichenko and observer – Alexei Sergeev.

The comet was also photographed by Timur Kryachko. We wait for the morning sky to rise in the USA. We hope the large telescopes here will also confirm our object.

To be continued…

December 2010
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