Electronic Telegram No. 1069 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 SUPERNOVA 2007iu F. Yuan, J. Aretakis, and C. Akerlof, University of Michigan; and R. Quimby, California Institute of Technology, on behalf of the ROTSE collaboration, report the discovery of a supernova located at R.A. = 1h25m20s.11, Decl. = +8o54'12".7 (equinox 2000.0) in unfiltered CCD images taken with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory. SN 2007iu, which is blended with a nearby USNO-catalogue star of mag 16.2 in the ROTSE images, was at mag 19.0 +/- 0.4 mag on Sept. 8.24 UT and at mag 18.6 +/- 0.1 on Sept. 14.23; nothing was visible to limiting mag about 19.0 at this position in images taken on Sept. 7.95 by the ROTSE-IIIc telescope at the H.E.S.S. site at Mt. Gamsberg, Namibia (the magnitudes are unfiltered and calibrated relative to USNO-B1.0-catalogue R magnitudes). No host galaxy is visible in the ROTSE images or on the Digitized Sky Survey. A finding chart of the supernova can be found at the following URL: http://www.rotse.net/transients/j0125+0854/070914_012520+085413.jpg. Quimby adds that a spectrum (420-890 nm) of 2007iu, obtained on Sept. 15.28 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by M. Shetrone, V. Riley, and F. Deglman, shows it to be a type-II supernova. Emission lines from H-alpha, H-beta, and H-gamma are detected, and a redshift of z = 0.09 is inferred from the line peaks. Weak emission lines from He II 468.6-nm and possibly O III 500.7-nm are also seen. An emission peak is observed at rest wavelength 588 nm, which, if identified with Na I, would imply a blueshift relative to the Balmer lines of about 600 km/s. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2007 CBAT 2007 September 15 (CBET 1069) Daniel W. E. Green