Electronic Telegram No. 2594 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION CBAT Director: Daniel W. E. Green; Hoffman Lab 209; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A. e-mail: cbatiau@eps.harvard.edu (alternate cbat@iau.org) URL http://www.cbat.eps.harvard.edu/index.html Prepared using the Tamkin Foundation Computer Network APPARENT NOVA IN M31 Jiangao Ruan, Fangchenggang, Guangxi, China; and Xing Gao, Urumqi, Xinjiang, China, report the discovery of a possible nova (mag approximately 17.2) on one 60-s unfiltered CCD survey image (limiting mag about 19.0) taken by Xing Gao in the course of the Xingming Observatory Sky Survey at Mt. Nanshan around Dec. 15.528 UT using a Celestron C14 35.6-cm f/6.9 Schmidt- Cassegrain telescope. The new object is approximately located at R.A. = 0h42m56s.67 +/- 0s.01, Decl. = +41d17'21".2 +/- 0".1 (equinox 2000.0), which is about 139" east and 73" north of the center of NGC 224. Additional Xingming magnitudes for the variable: Dec. 13, [19.0; 14, [19.0; 16.517, 17.1; 16.518, 17.0. Nothing is visible at this position on a Digitized Sky Survey image (from a IIIa-J plate + GG495 filter) taken on 1985 Dec. 17. The Xingming images have been posted at the following website URL: http://www.xjltp.com/XOSS/XM08JR/XM08JR.htm. Kamil Hornoch and Adrian Galad, Astronomical Institute, Ondrejov, report their independent discovery of the above variable in M31 on a co-added 2340-s R-band CCD frame taken under poor conditions on Dec. 16.729 UT with the 0.65-m telescope at Ondrejov. The new object is well visible on single images used for the co-added frame and is located at R.A. = 0h42m56s.67, Decl. = +41o17'21".3 (equinox 2000.0), which is 139" east and 73" north of the center of M31. The measured position is only about 0".7 from the best position for the "Fe II"-class nova M31N 2010-01a (cf. CBETs 2124, 2127, 2136, 2187) that was measured by Hornoch from the 2.4-m Hiltner telescope image taken by J. Prieto and R. Khan on 2010 Jan. 13.110 UT, which suggests that the currently detected bright object could be caused by another outburst of M31N 2010-01a. Available R-band magnitudes for the variable during its current outburst, measured by Hornoch: Dec. 4.211 UT, [21.7 (P. Garnavich and J. Pagnini, 1.83-m Vatican Advanced Technology Telescope + Vatt4k imager); 13.930, [18.5 (Hornoch, 0.65-m telescope at Ondrejov); 16.729, R = 16.5 +/- 0.1 (Hornoch and Galad, 0.65-m telescope at Ondrejov). Following a request from Kabashima and Nishiyama, T. Yusa (Osaki, Japan) writes that he has confirmed the appearance of the above variable at mag 16.4 on 90-s unfiltered CCD exposures (limiting mag 18.5) taken on Dec. 17.392 UT using a 0.30-m f/7 Cassegrain telescope (+ SBIG STL-1001E camera); he measured position end figures 56s.64, 21".3 for the variable, and his image is posted at URL http://www.palette.furukawa.miyagi.jp/space/images/PNinM31_101217.jpg. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 December 18 (CBET 2594) Daniel W. E. Green