Electronic Telegram No. 2879 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 P/2011 UA134 (SPACEWATCH-PANSTARRS) 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 Ritchey-Chretien 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" 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 f/4.64 reflector) reports that stacked images (45 min total exposure) taken in good seeing on Oct. 29.14-29.16 show a compact coma 8" wide (with FWHM about 25 percent larger than stars nearby) with total red mag 19.8 and a tail at least 15" long in p.a. around 260 deg. T. Vorobjov, L. Buzzi, and S. Foglia measured images taken by R. Holmes (Ashmore, IL, USA, 0.61-m f/4 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 UA134 (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 24.44466 4 43 44.87 +26 30 55.5 20.4 " 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 25.44013 4 43 59.98 +26 40 16.3 21.2 " 25.45457 4 44 00.14 +26 40 24.6 21.2 " 25.46901 4 44 00.31 +26 40 32.9 21.3 " The available astrometry, the following elliptical orbital elements by G. V. Williams, and an ephemeris appear on MPEC 2011-U108. T = 2011 Dec. 4.9255 TT Peri. = 31.4910 e = 0.627916 Node = 40.4814 2000.0 q = 2.046893 AU Incl. = 10.4512 a = 5.501157 AU n = 0.0763876 P = 12.90 years NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 October 31 (CBET 2879) Daniel W. E. Green