Electronic Telegram No. 1662 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 2008ir, 2008is, AND 2008it D. Sand, Harvard-Smithsonian Center for Astrophysics and Las Cumbres Observatory Global Telescope Network; M. L. Graham and C. Bildfell, University of Victoria; D. W. Just, S. Sivanandam, and S. Herbert-Fort, Steward Observatory; C. J. Pritchet, University of Victoria; H. Hoekstra, Leiden; and D. Zaritsky, Steward Observatory, report the discovery of three supernovae discovered with g'- and r'-band images obtained at the Canada-France-Hawaii Telescope (CFHT) with Megacam. Spectroscopic confirmation was obtained with the Blue Channel Spectrograph on the MMT, with utilization of the publicly available Supernova Identification code (Blondin and Tonry 2007, Ap.J. 666, 1024). The Megacam photometry given below all have uncertainty within +/- 0.1 mag. SN 2008 UT R.A. (2000.0) Decl. g' Offset 2008ir Nov. 27 8 16 12.44 - 7 21 32.3 18.7 1".19 E, 1".55 S 2008is Nov. 29 7 35 14.03 +39 16 52.1 20.4 0".89 E, 1".20 S 2008it Dec. 3 0 20 31.48 +28 55 31.1 20.9 0".31 E, 0".21 S The apparent host galaxy for 2008ir has g' = 22.42 +/- 0.06 and r' = 21.74 +/- 0.04. The apparent host galaxy for 2008is has g' = 19.28 +/- 0.01 and r' = 18.87 +/- 0.01. The apparent host galaxy for 2008it has g' = 22.59 +/- 0.01 and r' = 21.73 +/- 0.01. Additional magnitudes from Dec. 22: 2008ir, g' = 20.8 +/- 0.1, r' = 19.6 +/- 0.1; 2008is, g' = 21.7 +/- 0.1, r' = 20.8 +/- 0.1. [Regarding the designation 2008ir, see also the editorial note on CBET 1645.] Additional Photometry Spectroscopy Days After SN 2008 UT r' Date 2008 UT Type Maximum z 2008ir Nov. 27 18.6 Dec. 19 Ia 15-20 0.066 2008is Nov. 29 20.1 Dec. 29 Ia 20 0.12 2008it Dec. 3 20.9 Dec. 20 Ia 5-10 0.22 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2009 CBAT 2009 January 14 (CBET 1662) Daniel W. E. Green