Electronic Telegram No. 2378 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 SUPERNOVAE 2010gb, 2010gf, 2010gg Jose L. Prieto, Carnegie Observatories, reports that optical spectra (range 370-930 nm; resolution 0.7 nm) of 2010gb (cf. CBET 2366), 2010gf (cf. CBET 2370), and 2010gg (cf. CBET 2371) were obtained with the APO 3.5-m telescope (+ DIS) on July 18 UT. After cross-correlation with a library of supernova spectra using SNID (Blondin and Tonry 2007, Ap.J. 666, 1024), the following spectral classes were determined: 2010gb is a normal type-Ia supernova whose best spectral template is that of SN 2003cg at 11 days after maximum light; 2010gf is a type-II supernova a few weeks after explosion, with the best-fit spectral template being that of SN 1999em at 20 days after explosion; and 2010gg is an old type-II supernova. After correcting for the recession velocity of the host galaxy of SN 2010gb (UGC 9947, v = 6748 km/s; Schneider et al. 1992, Ap.J. Suppl. 81, 5), a blueshift of the Si II (rest 635.5 nm) line is measured to be 11000 km/s. A blueshifted velocity of the H-alpha P-Cyg profile for SN 2010gf is measured to be 4600 km/s after correcting for the recession velocity of its host galaxy, UGC 633 (v = 5574 km/s; de Vaucouleurs et al. 1991, Third Reference Catalogue of Bright Galaxies, via NED). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 July 19 (CBET 2378) Daniel W. E. Green