Electronic Telegram No. 2151 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 SUPERNOVAE 2010Q, 2010R, AND 2010S [Editor's note: this text replaces that on CBET 2150 (revised position for 2010S)] Further to CBET 2138, M. J. Graham, A. J. Drake, S. G. Djorgovski, A. Mahabal, and R. Williams, California Institute of Technology; J. L. Prieto, Carnegie Observatories; M. Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the CRTS discovery of additional supernovae in unfiltered CSS images: SN 2010 UT R.A. (2000.0) Decl. Mag. Offset 2010Q Jan. 15.40 10 26 27.11 +39 01 50.9 19.2 1" west 2010R Jan. 15.45 12 17 10.49 +25 39 58.7 18.3 1" west 2010S Jan. 16.12 1 39 04.48 - 0 37 12.2 18.4 -- Further CSS magnitudes for 2010Q: 2009 May 24.22, [20.4; Dec. 18.41, 19.9. Further CSS magnitudes for 2010R: 2009 June 22.22, [19.3. Further CSS magnitudes for 2010S: 2009 Dec. 15.18, [20.8. Spectrograms (range 390-700 nm) were obtained with the Palomar 5-m reflector (+ DBSP) on Jan. 17 UT. Cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (Blondin and Tonry 2007, Ap.J. 666, 1024) shows 2010S to be most similar to the type-Ic supernova 1997ef at two weeks before maximum light. SN 2010Q is most similar to the type-Ic supernova 1990B near maximum; clear, narrow H_alpha, H_beta, and O III emission lines from the host galaxy are seen in the spectrum at z = 0.055. SN 2010R is most similar to the the type-Ia supernova 1994S near maximum light; clear, narrow H_alpha, H_beta, and O III emission lines from the host galaxy are seen in the spectrum at z = 0.078. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 January 29 (CBET 2151) Daniel W. E. Green