Electronic Telegram No. 1186 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 2007sx-2007uw P. Challis, Harvard-Smithsonian Center for Astrophysics, has communicated the following item to the Central Bureau: J. M. Silverman, University of California, Berkeley, and G. Damke, Cerro Tololo Interamerican Observatory, on behalf of the ESSENCE project (cf. CBETs 717, 772, 830; IAUCs 8427, 8464), report the discovery of 52 supernovae on multiple R- and I-band images taken with the Blanco 4-m telescope (+ MOSAIC II camera) during Oct. 2-Dec. 21. Spectroscopic observations (range 380-890 nm) were obtained with the Keck I telescope (+ LRIS), the Magellan Clay Telescope (+ LDSS3), and the Gemini Observatory (+ GMOS) by project members. All of the objects were discovered at R magnitudes between 22.5 and 23.3. The table below contains the spectroscopic redshift, along with the spectroscopic supernova type, based on cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024). SN 2007 UT R.A. (2000.0) Decl. z Type 2007sx Oct. 2 1 10 09.248 - 0 42 08.04 0.12 II 2007sy Oct. 2 1 15 25.990 + 0 49 06.47 0.20 II 2007sz Oct. 2 2 07 00.226 - 5 06 08.17 0.02 II 2007ta Oct. 4 1 13 15.802 - 0 1 31.41 0.3 Ia 2007tb Oct. 4 1 14 41.246 + 0 46 51.84 0.4 Ia 2007tc Oct. 4 1 14 46.898 + 0 17 06.62 0.6 Ia 2007td Oct. 4 2 04 26.897 - 3 44 18.88 0.3 Ia 2007te Oct. 4 2 09 29.404 - 3 35 35.01 0.4 Ia 2007tf Oct. 6 1 09 59.350 - 0 1 06.95 0.4 Ia 2007tg Oct. 6 2 06 10.506 - 4 42 23.19 0.5 Ia 2007th Oct. 6 2 10 57.574 - 5 00 24.86 0.5 Ia 2007ti Oct. 8 2 10 09.837 - 4 39 49.31 0.5 Ia 2007tj Oct. 8 2 11 04.611 - 4 11 50.04 0.3 Ia 2007tk Oct. 8 2 30 24.610 - 8 17 54.44 0.3 Ia 2007tl Oct. 10 1 11 04.910 - 0 15 43.33 0.4 Ia 2007tm Oct. 10 2 06 04.735 - 3 32 29.33 0.5 Ia 2007tn Oct. 10 2 28 14.787 - 8 36 32.22 0.05 II 2007to Oct. 10 2 29 42.060 - 9 02 05.24 0.6 Ia 2007tp Oct. 10 2 30 23.940 - 9 13 39.85 0.5 Ia 2007tq Oct. 16 2 29 23.344 - 7 52 27.68 0.1 Ia 2007tr Oct. 18 1 10 48.009 + 0 13 36.75 0.3 Ia 2007ts Nov. 5 1 07 58.168 + 0 27 49.05 0.3 Ia 2007tt Nov. 5 1 11 20.520 - 0 12 19.34 0.4 Ia 2007tu Nov. 5 1 14 05.217 - 0 36 25.60 0.22 II 2007tv Nov. 5 2 05 13.329 - 5 01 42.46 0.3 Ia 2007tw Nov. 5 2 05 32.967 - 5 02 46.64 0.6 Ia 2007tx Nov. 5 2 28 33.313 - 8 35 25.70 0.7 Ia 2007ty Nov. 5 2 28 34.378 - 8 23 49.53 0.5 Ia 2007tz Nov. 5 2 30 07.146 - 8 43 09.31 0.5 Ia 2007ua Nov. 7 1 10 31.955 + 0 35 49.45 0.6 Ia 2007ub Nov. 7 2 07 24.136 - 3 51 55.20 0.5 Ia 2007uc Nov. 7 2 10 15.531 - 4 04 06.49 0.6 Ia 2007ud Nov. 7 2 30 13.148 - 9 15 39.45 0.6 Ia 2007ue Nov. 11 1 09 09.844 - 0 14 01.11 0.7 Ia 2007uf Nov. 11 2 06 30.884 - 4 09 55.03 0.5 Ia 2007ug Nov. 11 2 09 36.850 - 4 51 52.24 0.7 Ia 2007uh Nov. 13 2 06 05.198 - 4 01 37.51 0.6 Ia 2007ui Nov. 13 2 34 57.120 - 8 04 00.20 0.4 Ia 2007uj Nov. 15 2 33 19.034 - 8 32 30.21 0.3 Ia 2007uk Dec. 1 1 10 55.004 - 0 22 53.24 0.5 Ia 2007ul Dec. 1 2 07 16.535 - 4 42 23.22 0.6 Ia 2007um Dec. 3 1 12 29.208 + 0 17 01.22 0.3 Ia 2007un Dec. 3 1 14 22.735 + 1 07 45.64 0.3 Ia 2007uo Dec. 3 1 15 11.994 - 0 2 08.37 0.4 Ia 2007up Dec. 3 2 09 56.074 - 4 28 57.42 0.6 Ia 2007uq Dec. 7 2 04 21.312 - 3 54 10.91 0.4 Ia 2007ur Dec. 7 2 08 41.589 - 3 34 10.55 0.3 Ia 2007us Dec. 7 2 27 54.866 - 8 00 55.24 0.6 Ia 2007ut Dec. 7 2 30 23.638 - 9 12 20.02 0.4 Ia 2007uu Dec. 9 1 14 01.018 + 0 53 47.53 0.5 Ia 2007uv Dec. 12 1 14 43.185 + 0 54 27.71 0.5 Ia 2007uw Dec. 12 2 30 09.796 - 7 40 49.14 0.4 Ia NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2007 CBAT 2007 December 31 (CBET 1186) Daniel W. E. Green