Electronic Telegram No. 2258 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 2010bw-cj Further to CBET 2254, A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, 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 numerous apparent supernovae in unfiltered Catalina Sky Survey (CSS) images: SN 2010 UT R.A. (2000.0) Decl. Mag. Offset 2010bw Mar. 12.32 11 37 56.59 +10 53 38.0 19.4 2" W, 1" N 2010bx Mar. 17.30 9 27 42.21 +44 34 36.5 19.0 1" W 2010by Mar. 18.50 15 14 39.61 +28 25 21.4 18.4 1" E, 1" N 2010bz Mar. 19.41 13 18 30.11 +44 20 22.9 18.5 2" W, 3" S 2010ca Mar. 20.20 8 38 31.11 +14 00 39.1 19.1 1" W 2010cb Mar. 21.30 12 24 47.84 +32 06 54.9 18.4 4" W, 4" N 2010cc Mar. 21.38 12 14 43.72 +43 36 51.8 19.3 1" W, 1" N 2010cd Apr. 5.33 11 58 01.18 - 6 29 30.6 18.6 46" W, 14" N 2010ce Apr. 8.21 9 35 30.01 + 1 28 31.8 17.7 1" W, 1" N 2010cf Apr. 9.36 15 23 21.84 + 2 19 01.0 18.2 1" W, 2" S 2010cg Apr. 9.36 15 30 37.56 + 0 52 41.9 17.5 3" E, 4" S 2010ch Apr. 9.37 15 05 24.04 + 2 58 34.9 18.2 1" E 2010ci Apr. 12.15 7 52 58.89 + 5 29 29.9 17.7 3" E, 20" S 2010cj Apr. 12.22 8 47 57.98 +51 08 41.2 17.9 1" E, 1" N Follow-up observations of a number of objects were taken with the Palomar 1.52-m telescope with Gunn filters, noted by the g, r, and i magnitudes below. Further CSS magnitudes for 2010bw: 2009 June 24 [20.0; 2010 Mar. 5.37 UT, 19.1; Apr. 4.34, 20.0. A spectrogram was obtained with the Palomar 5-m reflector (+ DSBS) on Mar. 15 UT; cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2010bw is most similar to the type-Ia supernova 1999D at 11 days past maximum at redshift z = 0.12. Further CSS magnitudes for 2010bx: Jan. 16.29, [20.7; Apr. 11.21, 19.2. Further CSS magnitudes for 2010by: 2009 Sept. 23.12, [20.8; 2010 Mar. 18.50, 18.4; Mar. 25.39, 18.5; Apr. 4.47, 18.6; Apr. 13.36, 18.7. Further CSS magnitudes for 2010bz: 2009 July 5.23, [19.0; 2010 Mar. 14.33, 18.4; Mar. 20.29, 18.4; Mar. 21.38, 18.5; Apr. 11.26, 18.7. Further CSS magnitudes for 2010ca: Mar. 13.20, [20.5; Apr. 15.17, 18.3. Further CSS magnitudes for 2010cb: Mar. 5.47, [20.5; Apr. 7.35, 18.4; Apr. 16.17, 19.1. Further CSS magnitudes for 2010cc: 2009 Dec. 17.53, [20.4; 2010 Feb. 20.31, 18.8; Mar. 17.26, 19.1; Mar. 18.40, 19.3; Mar. 19.30, 19.3; Mar. 20.28, 19.4; Apr. 11.20, 20.0; Apr. 19.24, 20.3. Further magnitudes for 2010cd: Mar. 13.38, [20.1 (CSS); Apr. 10.36, g = 19.3, r = 18.7, i = 18.9. The host galaxy for 2010cd has redshift z = 0.053 (6dF, Jones et al. 2009). Further magnitudes for 2010ce: Feb. 9.34, [20.6 (CSS); Apr. 15.23, 17.9 (CSS); Apr. 10.23, g = 17.9, r = 18.9, i = 18.2. Further magnitudes for 2010cf: Mar. 16.48, [18.8 (CSS); Apr. 10.24, g = 18.4, r = 18.5, i = 18.6. Further CSS magnitudes for 2010cg: Feb. 15.49, [19.8; Mar. 16.48, 18.0. Further magnitudes for 2010ch: Feb. 15.49, [19.4 (CSS); Mar. 17.49, 19.1 (CSS); Apr. 10.24, g = 18.5, r = 18.4, i = 18.5. Further CSS magnitudes for 2010ci: Feb. 18.25, [19.4; Mar. 16.19, 16.5. The host galaxy has redshift z = 0.030 (Falco et al. 1999, PASP 111, 438). Further CSS magnitudes for 2010cj: Feb. 20.17, [20.5; Mar. 18.22, 17.0. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2010 CBAT 2010 April 22 (CBET 2258) Michael Rudenko