Electronic Telegram No. 544 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 SUPERNOVA 2006cy Further to IAUC 8622, R. Quimby and P. Mondol report the discovery of a supernova (mag about 17.2) in unfiltered CCD images taken on June 9.22 UT using the 0.45-m ROTSE-IIIb telescope at the McDonald Observatory. SN 2006cy is located at R.A. = 13h08m01s.23, Decl. = +26o06'59".0 (equinox 2000.0), which is 2".3 east and 13".1 south of the center of the apparent host galaxy (catalogued redshift of z = 0.036 from Rines et al. 2001, Ap.J. 561, L41; via NED). The supernova was found by subtracting a co-addition of images taken between 2004 Dec. 15 and 2006 Jan. 10 (limiting mag about 19.3) from the 2006 June images. The "Nearby Supernova Factory" collaboration (P. Antilogus, S. Gilles, R. Pain, and R. Pereira, Laboratoire de Physique Nucleaire et de Haute Energies de Paris; N. Blanc, Y. Copin, E. Gangler, and G. Smadja, Institut de Physique Nucleaire de Lyon; G. Aldering, C. Aragon, S. Bailey, S. Bongard, M. J. Childress, D. Kocevski, S. Loken, P. Nugent, S. Perlmutter, K. Runge, R. Scalzo, R. C. Thomas, L. Wang, and B. A. Weaver, Lawrence Berkeley National Laboratory, Berkeley; E. Pecontal and G. Rigaudier, Centre de Recherche Astronomique de Lyon; R. Kessler, Kavli Institute for Cosmological Physics, Chicago; and C. Baltay, A. Bauer, D. Herrera, and D. Rabinowitz, Yale University) reports that a spectrum (range 320-1000 nm) of 2006cy, obtained on June 10.4 UT with the Supernova Integral Field Spectrograph on the University of Hawaii 2.2-m telescope, reveals it to be a type-IIn supernova, exhibiting narrow emission features from H-alpha through H-delta, and also He I 587.6-, 667.8-, and 706.5-nm. NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars. (C) Copyright 2006 CBAT 2006 June 11 (CBET 544) Daniel W. E. Green