Electronic Telegram No. 2404 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 POSSIBLE SUPERNOVA IN GALAXY IN DRACO S. Nakano, Sumoto, Japan, reports the discovery by Koichi Itagaki (Teppo-cho, Yamagata) of an apparent supernova (mag 16.4) on unfiltered CCD frames (limiting magnitude 19.0) taken on Aug. 9.705 UT using a 0.60-m f/5.7 reflector (+ Bitran BT-214E camera). The new object is located at R.A. = 17h58m22s.56 +/- 0s.02, Decl. = +50o47'34".0 +/- 0".4 (equinox 2000.0), near a small and faint galaxy. Toru Yusa (Osaki, Japan) reports his confirming images (limiting mag 18-19) of the new object taken remotely at the RAS Observatory near Mayhill, NM, U.S.A., on Aug. 10.148 and 10.169, providing position end figures 22s.56 +/0 0s.01, 34".6 +/- 0".1. Additional unfiltered CCD magnitudes for the variable, including pre-discovery images found by Itagaki from his archive: 2008 Aug. 31.50, [19.5 (Itagaki); 2010 Aug. 3.614, 17.5 (Itagaki); 6.576, 16.9 (Itagaki); 10.148, 16.0 (Yusa, 0.30-m f/12 reflector + FLI IMG1024-DM camera); 10.169, 16.0 (Yusa, 0.25-m f/3.4 reflector + SBIG ST-10XME camera); 10.446, 16.2 (Itagaki); 10.527, 16.3 (Yusa, 0.30-m f/12 Cassegrain reflector + SBIG STL-1001E camera at Osaki, Japan). Itagaki's pre- and discovery images of the new variable are posted at website URL http://www.k-itagaki.jp/images/psn-anon-2.jpg. Also, Yusa has posted an image of the variable at the following website URL: http://www.palette.furukawa.miyagi.jp/space/images/PSN_100810.jpg. The faint presumed host galaxy is SDSS J175822.33+504733.1. Following posting on the Central Bureau's unconfirmed-objects webpage, Vitali Nevski (Vitebsk, Belarus) writes that he obtained CCD images on Aug. 10.880 with a 0.3-m reflector that yield magnitude 15.8 and position end figures 22s.58, 34".7 (USNO-B1.0 catalogue) for the possible supernova, adding that nothing is visible at this position on a Palomar Sky Survey image obtained on 1993 Aug. 16 (via the Digitized Sky Survey; limiting red mag 21). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 August 11 (CBET 2404) Daniel W. E. Green