Electronic Telegram No. 2171 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 2010aa IN NGC 692 L. A. G. Monard, Pretoria, South Africa, reports his discovery of an apparent supernova (magnitude 16.4 +/- 0.2) on six unfiltered CCD images obtained on Feb. 9.771 UT at the Bronberg Observatory, the position of the new object given as R.A. = 1h48m43s.21, Decl. = -48d39'00".7 (equinox 2000.0), which is 11" east and 7" south of the core of the type-Sbc galaxy NGC 692. Nothing is visible at this position Digitized Sky Survey images (limiting red mag 20.5), on the previous image of this galaxy taken at the Bronberg Observatory on 2009 Dec. 17.793 (limiting mag 18.7), or on earlier images by Monard. Monard also discovered the type-Ia supernova 2007st (cf. CBETs 1177, 1190) in this galaxy. Following posting on the Central Bureau's unconfirmed- objects webpage, P. Marples (Loganholme, Queensland, Australia) writes that S. Parker (Oxford, Canterbury, New Zealand) found that 2010aa is clearly visible at red mag 15.7 in a prediscovery CCD image taken by Parker using a 35-cm Celestron C14 Schmidt-Cassegrain reflector on 2010 Feb. 4.443; the magnitude and position end figures 43s.24, 01".3 were measured by C. Drescher (Calamvale, Queensland, Australia) using Astrometrica with the USNO-B1.0 catalogue, from Parker's image. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 February 10 (CBET 2171) Daniel W. E. Green