Electronic Telegram No. 1561 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) CBAT@CFA.HARVARD.EDU (science) URL http://www.cfa.harvard.edu/iau/cbat.html SUPERNOVA 2008gx IN NGC 3144 Markku Nissinen and Veli-Pekka Hentunen, Kangaslampi, Varkaus, Finland, report the discovery of an apparent supernova (mag 16.8) on CCD images (limiting mag 19.1) taken over three hours beginning on Nov. 4.857 UT with a 30.5-cm Meade LX200 f/10 reflector (+ SBIG ST8-XME camera + Bessel R filter). The new object is located at R.A. = 10h15m32s.95, Decl. = +74o12'59".1 (equinox 2000.0), which is 3" east and 14" south of the center of the galaxy NGC 3144. Nothing is visible at this position on their 150-s unfiltered image taken on 2008 Oct. 22 (limiting red mag 19.7) or on a Palomar Sky Survey F image (via the Digitized Sky Survey; limiting red mag 20.8). At their request, A. Oksanen (Muurame, Finland) obtained confirming CCD images with a 40-cm reflector on Nov. 5.136 showing 2008gx at magnitude V = 16.9 and at position end figures 32s.92, 59".4; an additional image taken by Oksanen on Nov. 5.681 yields V = 16.8 and position end figures 32s.90, 59".8. Oksanen has posted an image of 2008gx at the following website URL: http://murtoinen.dyndns.org/ccd/ngc3174/NGC%203174_V_20081105T1620.jpg. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2008 CBAT 2008 November 6 (CBET 1561) Daniel W. E. Green