Electronic Telegram No. 2172 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Room 209; Dept. of Earth and Planetary Sciences; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbat@cfa.harvard.edu; dwe_green@eps.harvard.edu URL http://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2010ab IN PGC 27294 T. Boles, Coddenham, England, reports the discovery of an apparent supernova (mag 18.3) on unfiltered CCD images taken on Feb. 11.868 and 13.066 UT with a 0.35-m reflector. The new object is located at R.A. = 9h35m56s.03, Decl. = +74o00'00".6 (equinox 2000.0; average from fifteen images), which is approximately 6".9 east and 3".3 north of the center of PGC 27294 (= MCG +12-9-56). Nothing is present at this position on Boles' images from 2006 Mar. 5 and 2006 Jan. 20 (limiting mag 19.5) or on Digitized Sky Survey plates from 1991 Dec. 6 (limiting red mag 20.5) and 1952 Aug. 22 (limiting blue mag 21.0). Following posting on the Central Bureau's unconfirmed-objects webpage, P. Corelli, Pagnacco, Italy, reports magnitude 18.3 and position end figures 55s.89, 00".3 for 2010ab from a eight 90-s co-added unfiltered CCD frames taken on Feb. 13.92 with a 45-cm f/4.4 reflector. G. Cortini and S. Antonellini, Predappio, Italy, report that 2010ab was at magnitude near 17.8 on Feb. 14.02 (100-s exposure with a Celestron 14 telescope and a Starlight X-press MX 916 camera). J. Brimacombe, Cairns, Australia, using a remotely operated 50-cm reflector (+ STL6K camera) at New Mexico Skies, Mayhill, NM, U.S.A., measured mag 18.9 (and offset 7" east and 3" north of the host-galaxy core) for 2010ab from five 600-s co-added images (limiting magnitude 20) on Feb. 14.08, adding that nothing is visible at this position on Digitized Sky Survey images (limiting mag 20.5); he has posted his image at the following website URL: http://www.flickr.com/photos/43846774@N02/4356068574/ NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 February 14 (CBET 2172) Daniel W. E. Green