Electronic Telegram No. 2343 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@iau.org; cbatiau@eps.harvard.edu URL http://www.cfa.harvard.edu/iau/cbat.html APPARENT NOVA IN M31: M31N 2010-06c V. Burwitz, Max-Planck-Institut fuer Extraterrestrische Physik (MPE); Observatorio Astronomico de Mallorca (OAM); W. Pietsch and M. Henze, MPE; J. Rodriguez, OAM; and C. A. Haswell, S. Holmes, U. Kolb, and R. Lucas, The Open University (TOU), report the discovery of an apparent nova (R magnitude 17.8) in M31 on a stack of five 120-s unfiltered CCD images obtained with the 0.35-m f/11 TOU/OAM "PIRATE" Schmidt-Cassegrain telescope (+ SBIG STL-1001E CCD camera) at Costitx, Mallorca, on June 26.084 UT. The new object, designated M31N 2010-06c, is located at R.A. = 0h44m04s.48, Decl. = +41d28'34".2 (equinox 2000.0; uncertainty 0".3), which is 902" east and 746" north of the core of M31. No object is visible at this position on a PIRATE image taken on June 17.093 (limiting R mag 19.0). M31N 2010-06c is clearly detected in the individual images. All measured magnitudes are from a photometric solution using R magnitudes of the Local Group Survey M31 catalogue of Massey et al. (2006, A.J. 131, 2478). Pietsch, Henze, and Burwitz -- together with A. Liakos (Department of Physics, University of Athens), D. Hatzidimitriou (Department of Physics, University of Crete), and P. Niarchos (Department of Physics, University of Athens) -- add that confirmation of M31N 2010-06c at mag 18.0 was obtained with a stack of ten 60-s unfiltered CCD images obtained with a 40-cm Cassegrain telescope (+ f/5.1 focal reducer + 2184x1472-pixel ST-10XME CCD camera; pixel size 6.8 microns square) at the Athens University Observatory on June 27.028 UT; they provide position end figures 04s.48, 33".8. K. Hornoch provides magnitude R = 17.6 +/- 0.15 and position end figures 04s.47, 34".2 (offset 902" east, 746" north of the center of M31) for M31N 2010-06c, as measured from a co-added 630-s R-band CCD frame taken by himself with the 0.65-m telescope at Ondrejov on June 26.997 UT. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 June 29 (CBET 2343) Daniel W. E. Green