Electronic Telegram No. 1861 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 2009gm-2009gs AND POSSIBLE SUPERNOVAE K0905-10, K0905-11, K0905-12 Further to CBET 1830, A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams, California Institute of Technology; M. Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore, S. M. Larson, R. Hill, R. Kowalski, A. Boattini, and A. Gibbs, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the CRTS discovery of several apparent supernovae and three possible supernovae in unfiltered Catalina Sky Survey (CSS) images: SN 2009 UT R.A. (2000.0) Decl. Mag. Offset 2009gm May 23.16 14 27 58.10 +11 24 33.9 18.2 8".7 E, 8".9 S 2009gn May 26.30 16 05 23.53 -16 08 34.2 18.0 2".2 W, 5".6 N 2009go May 29.36 16 38 54.17 +21 49 06.0 18.3 2".0 W, 2".0 N 2009gp May 30.25 14 19 33.93 + 2 44 45.5 19.0 0".2 W, 2".0 N 2009gq June 2.40 22 14 52.81 +17 30 47.2 18.3 5".5 W, 14".7 N 2009gr June 14.42 17 25 38.28 +19 07 05.8 18.8 3".5 E, 3".0 N 2009gs June 15.44 21 18 49.42 - 5 57 10.8 16.6 1".1 E, 0".4 N PSN 2009 UT R.A. (2000.0) Decl. Mag. Offset K0905-10 May 23.16 14 26 47.44 +12 35 29.1 18.5 0".4 E, 0".8 N K0905-11 May 26.27 13 51 43.30 + 9 06 53.2 19.4 0".2 W, 0".1 N K0905-12 May 30.35 14 20 21.31 +29 11 59.4 19.1 1".1 W, 0".2 N Discoveries were compared with reference images from deeper Sloan Digital Sky Survey, Canada-France-Hawaii Telescope, and Digitized Sky Survey images, as well as CSS and "Palomar Quest" co-added images and CSS lightcurves. The objects were followed with the Palomar 1.5-m telescope using Gunn filters. Further magnitudes for 2009gm: Apr. 28.38, [20.7 (CSS); May 27.22, g = 18.9, r = 18.0, i = 18.1 (Palomar); June 1.25, 18.4 (CSS); 16.24, 19.2 (CSS). Further magnitudes for 2009gn: Apr. 19.43, [20.2 (CSS); 30.39, 18.5 (CSS); May 27.23, g = 18.6, r = 18.3, i = 18.5 (Palomar); June 14.26, 18.6 (CSS). Further magnitudes for 2009go: May 4.37, [20.4 (CSS); 16.33, 18.7 (CSS); June 2.22, g = 18.4, r = 18.4, i = 18.6 (Palomar); 4.20, g = 18.8, r = 18.8, i = 18.6 (Palomar); 16.42, g = 19.7, r = 19.5, i = 19.8 (Palomar); 21.33, 19.6 (CSS). Further magnitudes for 2009gp: Apr. 27.35, [20.2 (CSS); May 24.27, 18.9 (CSS); June 2.21, g = 19.2, r = 18.9, i = 19.2 (Palomar); 15.25, 19.8 (CSS). Further magnitudes for 2009gq: Apr. 29.48, [20.2 (CSS); June 11.44, 18.7 (CSS); 16.41, g = 19.2, r = 18.9 (Palomar); 22.40, 19.2 (CSS). Further magnitudes for 2009gr: Feb. 5.53, [20.0 (CSS); May 27.37, 18.1 (CSS); June 22.37, 19.3 (CSS). Further magnitudes for 2009gs: May 27.44, [20.1 (CSS); June 16.44, g = 16.4, r = 16.5, i = 16.6 (Palomar). Further magnitudes for K0905-10: Apr. 18.44 UT, [20.0 (CSS); 28.38, 19.5 (CSS); May 27.22, g = 18.6, r = 18.6, i = 18.7 (Palomar); June 1.25, 18.6 (CSS); 16.24, 19.3 (CSS). Further magnitudes for K0905-11: Apr. 28.35, [20.5 (CSS); May 27.22, g = 19.4, r = 19.4, i = 19.4 (Palomar); June 11.26, 19.9 (CSS). Further magnitudes for K0905-12: May 13.37, [20.5 (CSS); June 2.20, g = 19.3, r = 19.3, i = 19.4 (Palomar); 17.18, 19.5 (CSS). D. Milisavljevic, R. Fesen, and J. Parrent, Dartmouth College, report that a low-dispersion spectrum (range 420-790 nm) of 2009gs, obtained on June 20.7 UT with the 2.4-m Hiltner telescope (+ CCDS) at MDM Observatory, shows it to be a normal type-Ia supernova. Comparison with a library of supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) provides a good match with the normal type-Ia supernova 1995E at maximum light. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 June 25 (CBET 1861) Daniel W. E. Green