Electronic Telegram No. 2212 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 NOVAE IN M31 Kamil Hornoch, Ondrejov Observatory, reports his discovery of another apparent nova in the galaxy M31 made on a co-added 1740-s R-band CCD frame taken with the 0.65-m telescope at Ondrejov on Mar. 17.765 UT; the new object is visible on single images used for the co-added image, but it is not present on numerous archival images taken at Lelekovice and Ondrejov back to 2002. The new object is also visible on a pre-discovery R-band CCD frame taken by Hornoch with the same instrumentation on Mar. 9.746. Designated M31N 2010-03b, the presumed nova is located at R.A. = 0h42m55s.87, Decl. = +41o15'19".6 (equinox 2000.0), which is 130" east and 49" south of the center of M31. R-band magnitudes measured by Hornoch for M31N 2010-03b: 2010 Jan. 31.838, [21.1 (P. Kubanek, N. Morales, J. L. Ortiz, J. Gorosabel, and M. Jelinek, 1.23-m telescope at Calar Alto); Feb. 25.745, [20.0 (Hornoch, 0.65-m telescope at Ondrejov); Mar. 7.773, [19.7 (P. Kusnirak, 0.65-m telescope at Ondrejov); 9.746, 18.3 +/- 0.3 (Hornoch); 17.765, 16.9 +/- 0.1 (Hornoch); 18.763, 17.2 +/- 0.1 (Hornoch, M. Wolf, and P. Zasche, 0.65-m telescope at Ondrejov). Additional R-band magnitudes for M31N 2010-02a (cf. CBETs 2190 and 2192) measured by Hornoch: Mar. 4.773 UT, 17.5 +/- 0.15 (Hornoch and Wolf, 0.65-m telescope at Ondrejov); 7.773, 18.3 +/- 0.2 (Kusnirak); 9.749, 18.5 +/- 0.3 (Hornoch); 17.765, [19.1 (Hornoch). Additional R-band magnitudes for M31N 2010-03a (cf. CBET 2192) measured by Hornoch: Mar. 4.773 UT, 17.0 +/- 0.2 (Hornoch and Wolf); 7.773, 17.2 +/- 0.2 (Kusnirak); 9.749, 17.4 +/- 0.3 (Hornoch); 17.765, 17.5 +/- 0.2 (Hornoch); 18.763, 18.0 +/- 0.3 (Hornoch, Wolf, and Zasche, 0.65-m telescope at Ondrejov). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 March 20 (CBET 2212) Daniel W. E. Green