Electronic Telegram No. 1682 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 POSSIBLE SUPERNOVAE K0810-1; K0811-1 TO K0811-4; K0812-1 TO K0812-6; K0901-1 Further to CBET 1681, A. J. Drake, S. G. Djorgovski, R. Williams, A. Mahabal, and M. J. Graham, California Institute of Technology; M. Catelan, Pontificia Universidad Catolica; and E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona, report the CRTS discovery of several possible supernovae in unfiltered CSS images: PSN 2008/9 UT R.A. (2000.0) Decl. Mag. Offset K0810-1 Oct. 30.51 10 05 00.27 +14 22 49.9 18.3 0".9 E, 0".1 S K0811-1 Nov. 18.18 2 53 14.87 +20 06 13.2 18.9 1".4 W, 0".3 N K0811-2 Nov. 19.21 1 30 54.81 -01 42 08.2 19.2 K0811-3 Nov. 19.21 1 59 30.24 -01 26 21.3 18.3 0".2 W, 0".7 S K0811-4 Nov. 30.34 8 28 17.16 +30 24 54.1 19.7 4".5 N, 0".1 S K0812-1 Dec. 1.27 2 37 59.31 +01 30 29.3 18.4 0".9 E K0812-2 Dec. 1.52 10 33 53.80 -03 21 25.4 18.3 0".5 W, 1".1 N K0812-3 Dec. 4.52 11 09 32.94 +27 24 40.3 18.1 0".1 N K0812-4 Dec. 20.17 2 16 52.47 +13 55 00.7 17.9 0".3 E, 0".8 S K0812-5 Dec. 22.55 12 11 50.13 +15 54 51.3 19.4 0".7 E, 0".7 N K0812-6 Dec. 29.55 13 45 26.56 -10 43 52.8 17.9 K0901-1 Jan. 2.52 13 00 37.49 +17 50 57.0 18.9 The Palomar 1.52-m reflector (+ Gunn filters) was used for follow-up photometry with Gunn g, r, and i filters, as listed below (otherwise, magnitudes unfiltered CSS images, where so stated). The host galaxy of PSN K0810-1, SDSS J100500.21+142250.0, has Gunn magnitudes u = 22.6, g = 22.9, r = 22.3, i = 22.4, and g = 21.4. Additional magnitudes for PSN K0810-1: 2008 June 13.17, [20.2 (CSS); Oct. 31.46, g = 19.1, r = 18.8, i = 18.9; Nov. 7.51, 18.3 (CSS); 2009 Jan. 28.32, 19.5 (CSS). The host galaxy of PSN K0811-1, SDSS J025314.97+200612.9, has Gunn magnitudes u = 22.3, g = 22.0, r = 21.3, i = 20.9, and g = 22.2. Additional magnitudes for PSN K0811-1: 2008 Sept. 30.35, [20.5 (CSS); Nov. 20.1, g = 19.2, r = 19.3, i = 19.0; Dec. 20.22, 19.3 (CSS); 2009 Jan. 17.22, 19.8 (CSS). PSN K0811-2 has no clear host galaxy in Palomar co-added images or DSS images. Additional magnitudes for PSN K0811-2: 2008 Nov. 3.26, [20.8 (CSS); Nov. 20.1, g = 18.3, r = 18.9, i = 19.3; Dec. 1.24, 18.2 (CSS); Dec. 31.15, 18.3 (CSS). PSN K0811-3 has a faint apparent host galaxy of Gunn magnitude r = 22 in Palomar co-added images. Additional magnitudes for PSN K0811-3: 2008 Nov. 3.26, [20.7 (CSS); Nov. 20.1, g = 18.0, r = 19.2, i = 19.0; Dec. 1.24, 17.7 (CSS); Dec. 2.16, g = 17.8, r = 18.9, i = 18.8; Dec. 31.18, 19.4 (CSS). The host galaxy of PSN K0811-4, SDSS J082816.81+302454.2, has Gunn magnitudes u > 21, g = 22.4, r = 22.5, i = 21.8, and z = 21.1, and resides in the cluster Abell 671 at redshift z = 0.05. Additional CSS magnitudes for PSN K0811-4: 2008 Nov. 21.41, [20.8; Dec. 31.34, 18.0; 2009 Jan. 20.37, 18.5. PSN K0812-1 has a faint apparent host galaxy of Gunn magnitude r = 21.5 visible in Palomar co-added images. Additional magnitudes for PSN K0812-1: 2008 Nov. 6.25, [20.9 (CSS); Nov. 17.28, 18.5 (CSS); Dec. 2, g = 18.4, r = 18.5; Dec. 29.15, 19.3 (CSS). PSN K0812-2 has a faint apparent host galaxy of Gunn magnitude r = 22.5 visible in Sloan Digital Sky Survey (SDSS) images. Additional magnitudes for PSN K0812-2: 2008 Mar. 12.30, [20.6 (CSS); Dec. 2.41, g = 19.1, r = 18.4, i = 18.4; 2009 Jan. 18.45, 18.7 (CSS). The apparent host galaxy of PSN K0812-3, SDSS J110932.94+272440.2, has Gunn magnitudes u = 23.6, g = 21.7, r = 21.3, i = 21.4, and z = 20.9. Additional magnitudes for PSN K0812-3: 2008 Oct. 29.52, [20.9 (CSS); Dec. 5.47, g = 18.4, r = 18.1, i = 18.0; 2009 Jan. 2.42, 19.2 (CSS); Jan. 29.35, 19.6 (CSS). PSN K0812-4 has a faint apparent host galaxy of unknown brightness that is seen in SDSS and Palomar co-added images. Additional magnitudes for PSN K0812-4: 2008 Oct. 30.26 UT, [20.7 (CSS); Dec. 28.18, g = 18.5, r = 18.7; Dec. 29.11, g = 18.6, r = 18.6, i = 19.1; 2009 Jan. 18.16, 19.4 (CSS). The host galaxy of PSN K0812-5, SDSS J121150.08+155450.6, has Gunn magnitudes u > 21, g = 22.9, r = 22.6, i = 22.2, and z = 21.6. Additional magnitudes for PSN K0812-5: 2008 May 5.26, [20.8 (CSS); Dec. 5.52, 19.1 (CSS); Dec. 30.36, r = 19.3, i = 19.0; 2009 Jan. 25.44, 20.0 (CSS). PSN K0812-6 has no apparent host galaxy in Palomar co-added images (to r = 22) or on Digitized Sky Survey (DSS) images. Additional magnitudes for PSN K0812-6: 2008 July 1.17, [20.1 (CSS); Dec. 30.48, g = 17.8, r = 18.1, i = 18.5; 2009 Jan. 4.50, g = 18.1, r = 18.3, i = 18.8; Jan. 28.47, 19.0 (CSS). PSN K0901-1 has no apparent host galaxy to the limit of SDSS r images (limiting mag approximately 22.5). Additional magnitudes for PSN K0901-1: 2008 May 6.26, [20.6 (CSS); Dec. 6.53, 19.5 (CSS); 2009 Jan. 4.51, g = 19.6, r = 19.4; Jan. 25.48, 19.6 (CSS). NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 February 3 (CBET 1682) Daniel W. E. Green