Electronic Telegram No. 1245 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 2008ab, 2008ac, 2008ad F. Yuan, University of Michigan; R. Quimby, California Institute of Technology; M. D. Sisson, D. Chamarro, and C. Akerlof, University of Michigan; and J. C. Wheeler, University of Texas, on behalf of the ROTSE collaboration, report the discovery of three type-Ia supernovae in unfiltered CCD images taken with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory. SN 2008 UT R.A. (2000.0) Decl. Mag. Offset z 2008ab Jan. 30.23 11 34 45.92 +53 57 50.8 18.2 0.069 2008ac Jan. 30.27 11 53 45.18 +48 25 21.5 17.6 0".4 W, 0".5 N 0.053 2008ad Jan. 30.42 12 49 37.15 +28 19 46.5 18.0 3".5 E, 1".7 N 0.054 A faint (r = 20.65) galaxy is seen at the position of 2008ab in the Sloan Digital Sky Survey (SDSS); a finding chart for 2008ab is posted at http://rotse.net/rsvp/j113445.9+535751/j113445.9+535751.jpg. A finding chart for 2008ac is at http://rotse.net/rsvp/j115345.2+482521/j115345.2+482521.jpg. A finding chart for 2008ad can be found at the following website URL: http://rotse.net/rsvp/j124937.2+281946/. A quick reduction of red-channel (530-1000 nm) spectra of 2008ab and 2008ac, obtained on Feb. 1.34 by E. Ofek with the Palomar 5-m telescope (+ Double Beam Spectrograph), shows narrow emissions lines, likely from the host galaxies, that yield the redshifts tabulated above (that for 2008ac is in agreement with the SDSS redshift for the apparent host). Correcting for the host redshifts, the minima of the Si II 635.5-nm features are blue-shifted by 10600 km/s and 11000 km/s, respectively, for 2008ab and 2008ac. A spectrum (range 420-890 nm) of 2008ad, obtained on Jan. 31.34 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by S. Rostopchin and F. Deglman, is heavily contaminated by the host-galaxy light; correcting for the recession velocity of the host galaxy (z = 0.054 from narrow H II region lines in the host), the minimum of the Si II 635.5-nm feature is blue-shifted by 11700 km/s. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2008 CBAT 2008 February 9 (CBET 1245) Daniel W. E. Green