Electronic Telegram No. 2775 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 C/2011 O1 (LINEAR) An apparently asteroidal object discovered by the LINEAR survey (discovery observation tabulated below), and posted on the Minor Planet Center's NEOCP webpage, has been found by other CCD astrometrists to show cometary appearance. L. Buzzi (Varese, Italy, 0.38-m f/6.8 reflector) writes that stacked images taken in good seeing on July 31.9 UT show the object to be diffuse with a coma of size 8"-9" that is elongated in p.a. around 45 deg. H. Sato (Tokyo, Japan; remotely using a 0.51-m f/4.5 reflector at the RAS Observatory near Mayhill, NM, U.S.A.) reports a condensed coma of diameter 10" of total red mag 16.5 in a 4".9 circular aperture, with no tail visible, on Aug. 1.2. R. H. McNaught (Siding Spring Observatory, 0.5-m Uppsala Schmidt telescope) notes that the comet is in a dense star field but shows a coma of diameter about 12" (magnitude 16.9) on Aug. 1.5. 2011 UT R.A. (2000) Decl. Mag. Observer July 31.16245 17 18 31.78 -16 51 10.3 17.6 LINEAR The available astrometry, the following preliminary parabolic orbital elements by G. V. Williams, and an ephemeris appear on MPEC 2011-P03. T = 2012 July 23.5028 TT Peri. = 222.9903 Node = 89.2325 2000.0 q = 4.352910 AU Incl. = 79.8861 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2011 CBAT 2011 August 2 (CBET 2775) Daniel W. E. Green