[IAUC] CBET 3264: 20121022 : COMET C/2012 U1 (PANSTARRS)

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 3264
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 en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


COMET C/2012 U1 (PANSTARRS)
     Richard Wainscoat and Marco Micheli, University of Hawaii, report the
discovery of a comet in three w-band exposures taken with the 1.8-m
Pan-STARRS1 telescope at Haleakala (discovery observations tabulated below),
noting the object to appear slightly extended relative to adjacent field stars.
Micheli and Wainscoat later obtained three follow-up 120-s r-band exposures
on Oct. 19 using the Canada-France-Hawaii Telescope (queue observer Lisa
Wells), in which the object was seen to be clearly extended, but circularly
symmetric with no sign of a tail (FWHM of the comet measured to be
approximately 1".1, while that of adjacent stars was measured to be 0".75); at
the time of the observation, the object moved across a very faint background
galaxy, though it is not believed that the background galaxy contributed
significantly to the extension of the point-spread function PSF of the comet.
After posting on the Minor Planet Center's NEOCP webpage, other CCD
astrometrists have also commented on the object's cometary appearance.  H. Sato
(Tokyo, Japan; remotely using a 0.43-m f/6.8 astrograph at the RAS Observatory
near Mayhill, NM, U.S.A.; Oct. 20.3 UT) found a diffuse coma of diameter 18"
with total V-band magnitude 19.8 as measured within a circular aperture of
radius 9".5.  E. Guido, N. Howes, A. Tripp, and G. Sostero write that five
stacked 120-s R-band images taken with the 2.0-m f/10 "Faulkes Telescope North"
at Haleakala on Oct. 22.45 under good seeing conditions show a diffuse coma
nearly 5" in diameter.

     2012 UT             R.A. (2000) Decl.       Mag.
     Oct. 18.31653    1 53 13.66   +22 50 31.4   21.0
          18.32907    1 53 13.19   +22 50 32.4   21.0
          18.34161    1 53 12.75   +22 50 33.4   21.1

The available astrometry (including prediscovery Mount Lemmon Survey
observations from Oct. 17.4), the following preliminary parabolic orbital
elements by G. V. Williams, and an ephemeris appear on MPEC 2012-U66.

     T = 2014 June 30.9696 TT         Peri. =  58.0360
                                      Node  =  29.1949  2000.0
     q = 6.316809 AU                  Incl. =  66.7319


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

                         (C) Copyright 2012 CBAT
2012 October 22                  (CBET 3264)              Daniel W. E. Green