Electronic Telegram No. 1169 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 2007sp F. Yuan, University of Michigan; R. Quimby, California Institute of Technology; C. Akerlof, University of Michigan; and J. C. Wheeler, University of Texas, on behalf of the ROTSE collaboration, report the discovery of a supernova (mag about 16.8) in unfiltered CCD images taken with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory on Nov. 14.50 UT. The new object is located at R.A. = 12h04m42s.29, Decl. = +49o11'09".3 (equinxo 2000.0; uncertainty < 1"), which is 38".2 west and 2".4 south (about 20 kpc) from the apparent host galaxy galaxy. SN 2007sp decayed at a rate of about 0.05 magnitude/day and was observed at mag about 18.2 on Dec. 13.42. A spectrum (420-890 nm) of 2007sp, obtained on Dec. 13.45 with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by S. Rostopchin and E. Terrazas, shows it to be a type-Ia supernova about two months after maximum light; the shift of the spectral lines is consistent with the SDSS redshift for the nearby galaxy (z = 0.024). A finding chart for 2007sp can be found at the following website URL: http://rotse.net/rsvp/j120442+491109/j120442.3+491109.jpg NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2007 CBAT 2007 December 14 (CBET 1169) Daniel W. E. Green