Electronic Telegram No. 3688
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.htmlPrepared using the Tamkin Foundation Computer Network
COMET P/2013 US_10 (CATALINA)
An apparently asteroidal object discovered in Catalina Sky Survey images
taken by R. A. Kowalski on Oct. 31 UT (discovery observations tabulated
below), and given the minor-planet designation 2013 US_10 on Nov. 2 by the
Minor Planet Center on MPEC 2013-V05, has been found to show cometary
appearance by Richard Wainscoat on prediscovery images obtained with the
Pan-STARRS1 telescope at Haleakala following a request by G. V. Williams. In
each of the four 45-s w-band images taken on Aug. 14, the point-spread function
(PSF) of the object has a higher FWHM than adjacent stars, though there is no
obvious appearance of a tail or extended coma. Marco Micheii and Wainscoat
then scheduled queue observations with the Canada-France-Hawaii Telescope
(CFHT) on Nov. 5 (queue observer Lisa Wells); sixteen 60-s r-band exposures
showed the PSF of 2013 US_10 to be extended relative to adjacent stars; eight
co-added images with the best seeing conditions reveal no evidence of a tail,
but 2013 US_10 appears to be slightly asymmetric and is slightly more extended
towards p.a. approximately 50 degrees. Five additional 60-s r-band CFHT
exposures were obtained by Wainscoat and Micheli on Nov. 6 (queue observer
David Woodworth), tracked at the rate of 2013 US_10, and the object appears
extended relative to adjacent stars in each image; the shape of 2013 US_10 in
each image is clearly asymmetric, and is extended slightly towards p.a.
approximately 45 degrees.
2013 UT R.A. (2000) Decl. Mag. Observer
Oct. 31.16159 23 23 22.78 -14 15 07.6 18.6 Kowalski
31.17176 23 23 22.48 -14 15 09.7 18.8 "
31.18194 23 23 22.22 -14 15 11.3 18.5 "
31.23046 23 23 21.05 -14 15 16.5 18.6 "
31.23649 23 23 20.84 -14 15 17.6 18.4 "
31.24254 23 23 20.70 -14 15 19.4 18.6 "
31.24855 23 23 20.49 -14 15 20.4 18.1 "
The available astrometry (including prediscovery observations also from
Catalina on Sept. 1, 12, and 23,
and by L. Elenin at Mayhill on Sept. 9 -- all
of the prediscovery astrometry being identified by T. Spahr after the issuance
of MPEC 2013-V05; note that the Sept. 12 Catalina observations published on
MPEC 2013-V05 refer to a different object), the following parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2013-V31.
Epoch = 2015 Dec. 4.0 TT
T = 2015 Nov. 16.0225 TT Peri. = 340.3273
e = 1.000369 Node = 186.1603 2000.0
q = 0.824945 AU Incl. = 148.9055
NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.
(C) Copyright 2013 CBAT
2013 November 6 (CBET 3688) Daniel W. E. Green