Electronic Telegram No. 1617 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 2008id S. A. Rodney, Institute for Astronomy (IfA), University of Hawaii; R. Foley, Harvard-Smithsonian Center for Astrophysics; and C. J. Ma, IfA, on behalf of the "Pan-STARRS 1 (PS1) Science Consortium", report the discovery of a type-Ia supernova on r-band images from the "PS1 Medium Deep Survey" taken on Nov. 3.44 (with the new object at r = 21.2) and 6.47 UT (r = 20.8). SN 2008id is located at R.A. = 2h27m46s.80, Decl. = -4o34'47".1 (equinox 2000.0); the presumed faint host galaxy is located at position end figures 46s.97, 49".4. Nothing was visible at the position of 2008id on a reference image from Oct. 3.54 (to limiting r-band mag approximately 23). This is the first confirmed extragalactic transient object detected by the 1.8-m PS1 telescope on Haleakala, Maui. A spectrum of 2008id was obtained on Nov. 27.38 with the DEIMOS spectrograph on the 10-m Keck-2 telescope on Mauna Kea; using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) for cross-correlation against a library of template spectra, Rodney et al. find 2008id to be a type-Ia supernova at z = 0.26, about 21 days past maximum brightness. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2008 CBAT 2008 December 12 (CBET 1617) Daniel W. E. Green