Electronic Telegram No. 2559 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 NOVA IN M33: M33N 2010-11a Jiangao Ruan, Fangchenggang, Guangxi, China; and Xing Gao, Urumqi, Xinjiang, China, report the discovery of a possible nova (mag approximately 18.6) on several 60-s and 120-s survey images (limiting mag about 19.5) taken by Xing Gao in the course of the Xingming Observatory Sky Survey around Nov. 27.5297 UT using an unfiltered CCD camera with a Celestron C14 Schmidt-Cassegrain telescope at Mt. Nanshan. The new object is located at R.A. = 1h33m27s.55 +/- 0s.04, Decl. = +30d17'28".4 +/- 0".3 (equinox 2000.0). Additional magnitudes from Gao and Ruan: 1989 Dec. 4, [20.8 (Digitized Sky Survey, red plate); 2010 Nov. 25, [19.5; 26, [19.5; 27.835, 17.7; 28.527, 16.8. Their images have been posted at http://www.xjltp.com/XOSS/XM10BH/XM10BH.htm. The apparent nova was discovered independently by Koichi Nishiyama (Kurume, Japan) and Fujio Kabashima (Miyaki, Japan) at mag 16.7 on eight 40-s unfiltered CCD frames (limiting magnitude 19.4) taken around Nov. 28.542 UT with a Meade 200R 0.40-m f/9.8 reflector (+ SBIG STL1001E camera). They measure M33N 2010-11a to be located at position end figures 27s.54, 28".4, which is 301" west and 1329" south from the center of the galaxy M33. Additional magnitudes by Nishiyama and Kabashima for M33N 2010-11a: 1989 Dec. 4, [19.5 (DSS, infrared); 1991 Oct. 5, [19.4 (DSS, red); 2010 Nov. 24.551, [19.1; 26.520, [19.6; 29.629, 16.5. Following a request from Kabashima and Nishiyama, T. Yusa, Osaki, Japan, reports mag 16.1 and position end figures 27s.55, 28".5 for M33N 2010-11a from unfiltered CCD frames (limiting mag 18.5) taken on Nov. 29.064 UT remotely using a 0.25-m f/3.4 hyperbolic astrograph (+ SBIG ST-10XME camera) at the RAS Observatory near Mayhill, NM, U.S.A. Yusa's image has been posted at website URL http://space.geocities.jp/yusastar77/PNinM33_101129.htm. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 November 30 (CBET 2559) Daniel W. E. Green