Electronic Telegram No. 657 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://cfa-www.harvard.edu/iau/cbat.html SUPERNOVAE 2006hy, 2006hz, 2006ia, 2006ib Further to CBETs 611 and 656, B. Bassett, South African Astronomical Observatory (SAAO); A. Becker, University of Washington (UW); H. Brewington, Apache Point Observatory (APO); C. Choi, Seoul National University (SNU); D. Cinabro, Wayne State University; F. DeJongh, Fermilab; J. Dembicky, APO; D. L. DePoy, Ohio State University (OSU); B. Dilday, University of Chicago (UC); M. Doi, University of Tokyo (UoT); J. Frieman, Fermilab and UC; P. Garnavich, University of Notre Dame; M. Harvanek, APO; C. Hogan, UW; J. Holtzman, New Mexico State University; M. Im, SNU; S. Jha, Stanford University (SU); K. Konishi, UoT; J. Krzesinski, APO; H. Lampeitl, Space Telescope Science Institute (STScI); R. Kessler, UC; B. Ketzeback, D. Long, O. Malanushenko, and V. Malanushenko, APO; J. Marriner and D. McGinnis, Fermilab; R. McMillan, APO; G. Miknaitis, Fermilab; T. Morokuma, UoT; R. Nichol, University of Portsmouth (UP); K. Pan, APO; J. L. Prieto, OSU; M. Richmond, Rochester Institute of Technology; A. Riess, STScI; R. Romani, SU; M. Sako, University of Pennsylvania; G. Saurage, APO; D. Schneider, Pennsylvania State University; M. Smith, UP; S. Snedden, APO; N. Takanashi and K. Tokita, UoT; K. van der Heyden, SAAO; S. Watters, APO; C. Wheeler, University of Texas; N. Yasuda, UoT; and C. Zheng, SU, on behalf of the Sloan Digital Sky Survey II collaboration, report the discovery of four new supernovae on multiple g, r, and i images taken with the SDSS 2.5-m telescope at APO by the SDSS observing team. Marriner, McGinnis, and Dembicky report that observations with the ARC 3.5-m telescope at APO on Oct. 2 UT indicate that 2006ia, 2006ib, and 2006hy are all type-Ia supernovae. Romani, Zheng, Sako, Wheeler, and Schneider, together with U. Hopp (University of Munich) and W. Kollatschny (University of Goettingen), report that spectroscopic observations with the Hobby Eberly Telescope on Sept. 30 indicate that 2006hz is a type-II supernova. The discovery magnitudes tabulated below are all SDSS g magnitudes. Spectroscopic redshifts are given in the column labelled "z". Peak dates (all 2006) are approximate estimates from early fits to the multi-band light curves. SN Discov. R.A. (2000.0) Decl. Mag. z Estimated Date UT Peak Date 2006hy Sept. 15 22 08 19.43 - 1 11 47.0 22.3 0.14 Oct. 2 2006hz Sept. 19 0 12 41.00 - 0 32 07.7 21.6 0.23 Oct. 1 2006ia Sept. 22 2 07 19.18 + 1 15 07.5 21.0 0.18 Oct. 3 2006ib Sept. 22 3 16 11.83 - 0 36 03.4 22.1 0.18 Oct. 8 NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2006 CBAT 2006 October 3 (CBET 657) Daniel W. E. Green