2010CBET.2341....1H

Kamil Hornoch, Ondrejov Observatory, reports the discovery of an apparent nova in the galaxy M31 by P. Hornochova and himself on a co-added 1620-s R-band CCD frame taken with the 0.65-m telescope at Ondrejov on June 28.014 UT. The new object, designated M31N 2010-06a, is well visible on single images used for the co-added image, as well as on a pre-discovery, co-added, 3780-s R-band image taken by Hornoch on June 27.034 and on a co-added 2430-s R-band image taken on June 28.040 with the same instrumentation, but it is not present on numerous archive images taken at Lelekovice and Ondrejov. M31N 2010-06a is located at R.A. = 0:43:07.52, Decl. = +41:19:48.7 (equinox 2000.0), which is 261" east and 220" north of the center of M31. Available R-band magnitudes for M31N 2010-06a: June 18.152, [21.4 (P. Kubanek, J. Gorosabel, O. L. Gil, and M. Jelinek, 1.23-m telescope at Calar Alto); 23.038, [19.5 (K. Hornoch, 0.65-m telescope at Ondrejov); 25.995, [18.9 (Hornoch and Hornochova, 0.65-m telescope at Ondrejov); 27.034, 19.3 ± 0.2 (Hornoch); 28.014, 18.1 ± 0.1 (Hornoch and Hornochova); 28.040, 18.2 ± 0.1 (Hornoch and Hornochova).