[IAUC] IAUC 9239: P/2011 UA_134 [25139-2012/04-R1]

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                                                  Circular No. 9239
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
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CBATIAU en EPS.HARVARD.EDU           ISSN 0081-0304
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Prepared using the Tamkin Foundation Computer Network


COMET P/2011 UA_134 (SPACEWATCH-PANSTARRS)
     As first announced on CBET 2879, Larry Denneau, Richard
Wainscoat, and Henry Hsieh (Institute for Astronomy, University of
Hawaii) report the discovery of a comet on CCD images taken with
the "Pan-STARRS 1" 1.8-m telescope at Haleakala (discovery
observations tabulated below), noting that the point-spread
function (PSF) of the object's image is distinctly soft when
compared to those of nearby stars (and shows slight excesses
compared to expected stellar PSFs).  Six images were obtained using
the Canada-France-Hawaii Telescope on Oct. 26 UT by Marco Micheli
and Richard Wainscoat (queue observer Adam Draginda); Micheli
writes that the object appears slightly extended, with a stacked
image showing a 10" tail in p.a. about 255 deg (which is also
weakly visible in each single exposure).  After posting on the
Minor Planet Center's NEOCP webpage, L. Buzzi (Varese, Italy, 0.60-
m reflector) reports that stacked images taken in good seeing on
Oct. 29.14-29.16 show a compact coma 8" wide with total red mag
19.8 and a tail at least 15" long in p.a. about 260 deg.  T.
Vorobjov, L. Buzzi, and S. Foglia measured images taken by R.
Holmes (Ashmore, IL, USA, 0.61-m astrograph) on Oct. 30.2-30.3;
stacked exposures reveal an elongated 10" x 8" coma with a faint
tail 10" long in p.a. 270 deg.
     When the first night of observations were received by the
Minor Planet Center, they were automatically linked with a one-
night object observed the previous night by the Spacewatch project,
and based on those first two nights, the MPC automatically
designated the object as 2011 UA_134 (cf. MPS 396661).

     2011 UT             R.A. (2000) Decl.       Mag.   Observer
     Oct. 24.42686    4 43 44.60   +26 30 44.9   20.4   Spacewatch
          24.46591    4 43 45.08   +26 31 06.8   20.0     "
          25.42562    4 43 59.82   +26 40 08.0   21.4   Pan-STARRS
          25.46901    4 44 00.31   +26 40 32.9   21.3     "

The initial astrometry was published on MPEC 2011-U108; revised
osculating orbital elements by G. V. Williams from 38 observations,
Oct. 24-Nov. 3 (cf. MPEC 2011-V31):

                    Epoch = 2011 Dec. 25.0 TT
     T = 2011 Dec.  7.0770 TT         Peri. =  32.3049
     e = 0.630921                     Node  =  40.6022  2000.0
     q = 2.049671 AU                  Incl. =  10.5194
       a =  5.553482 AU    n = 0.0753106    P =  13.09 years

                      (C) Copyright 2011 CBAT
2011 November 9                (9239)            Daniel W. E. Green