Electronic Telegram No. 818 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://cfa-www.harvard.edu/iau/cbat.html SUPERNOVAE 2007N AND 2007O Further to IAUC 8798, N. Lee and W. Li report the LOSS/KAIT discovery of an apparent supernova (mag 17.3) on an unfiltered KAIT image obtained on Jan. 21.52 UT: SN 2007N is located at R.A. = 12h49m01s.25, Decl. = -9o27'10".2 (equinox 2000.0), which is 4".3 west and 14".3 north of the center of MCG -01-33-12. Nothing was visible at this location on a KAIT image taken on 2006 Dec. 30.54 (limiting mag 19.0). Lee and Li also report the LOSS/KAIT discovery of another apparent supernova (mag 16.8) on an unfiltered KAIT image obtained on Jan. 21.60 UT: SN 2007O is located at R.A. = 14h56m05s.18, Decl. = +45o24'16".9 (equinox 2000.0), which is 8".2 east and 1".5 south of the center of UGC 9612. Nothing was visible at this location on a KAIT image taken on 2006 July 5.23 (limiting mag 19.5). J. M. Silverman, R. J. Foley, and A. V. Filippenko, University of California, Berkeley, report that inspection of CCD spectra (range 440-900 nm), obtained on Jan. 22 UT with the Keck II 10-m telescope (+ DEIMOS), shows that 2007N and 2007O are type-Ia supernovae. SN 2007N appears similar to SN 1991bg (Filippenko et al. 1992, A.J. 104, 1543) at one day after maximum brightness, although the spectrum does not go to sufficiently short wavelengths to see the Ti II trough that is characteristic of 1991bg-like supernovae. SN 2007O has a spectral-feature age (Riess et al. 1997, A.J. 114, 722) of 1 +/- 2 days past maximum brightness. Removing the recession velocities of 3750 km/s (from narrow absorption lines) and 10900 km/s (from narrow emission lines), the minimum of the Si II 635.5-nm feature is found to be blueshifted by 11200 and 10000 km/s, respectively. A. Harutyunyan, S. Benetti, I. Agnoletto, M. Turatto, and E. Cappellaro, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova; F. Ghinassi, Telescopio Nazionale Galileo (TNG); and S. Taubenberger, Max-Planck Institut fuer Astrophysik, Garching, report that a spectrum of 2007O, obtained on Jan. 23.21 UT with the 3.5-m TNG (+ DOLORES; range 328-800 nm, resolution 1.2 nm), shows it to be a type-Ia supernova near maximum light. The spectrum closely resembles that of 2003du (Stanishev et al. 2007, A.Ap., submitted) at 1 day before maximum light. Adopting a recession velocity of 10856 km/s (Sloan Digital Sky Survey "Data Release 4" obtained on 2005 August 17, via NED), the expansion velocity derived from the Si II line (635.5 nm) is about 9900 km/s. V. Stanishev, Physics Department, Stockholm University; and A. Harutyunyan and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, report that a spectrum of 2007N, obtained on Jan. 23.21 UT with the Nordic Optical Telescope (+ ALFOSC; range 350-910 nm) by T. Pursimo and H. Uthas, shows it to be a 1991bg-like type-Ia supernova around maximum light. The spectrum is similar to that of SN 1991bg around maximum (Gomez et al. 1996, A.J. 112, 2094) and can be seen at the following World Wide Web URL: http://www.physto.se/~vall/sne_classified.html. Notably, SN 2007N has much stronger and a significantly-more-blueshifted Ca II infrared triplet line than did 1991bg. The O I 777-nm absorption is also stronger. A narrow interstellar Na I 589.3-nm absorption is detected at the redshift of the host galaxy (v = 3861 km/s; Theureau et al. 2005, A.Ap. 430, 373) with an equivalent width of about 0.11 nm. The blueshift of the Si II line (635.5 nm) minimum is about 10800 km/s. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2007 CBAT 2007 January 23 (CBET 818) Daniel W. E. Green