2011CBET.2792....1N

Peter E. Nugent, Lawrence Berkeley National Laboratory (LBL) and University of California at Berkeley; Mark Sullivan, Oxford University; David Bersier, Liverpool John Moores University; D. A. Howell, Las Cumbres Observatory Global Telescope and University of California at Santa Barbara; Rollin Thomas, LBL; and Phil James, Liverpool John Moores University, report report the discovery of a type-Ia supernova (magnitude g = 17.2) by the "Type Ia supernova science working group of the Palomar Transient Factory" on g-band images obtained with the Oschin 1.2-m Schmidt telescope at Palomar on Aug. 24 UT. The supernova is located at R.A. = 14:03:05.81, Decl. = +54:16:25.4 (equinox 2000.0), which (according to D. Bishop, Rochester, NY, USA) is 59" west and 271" south of the center of M101; nothing was visible at this position on an image from Aug. 23 (limiting mag 20.6). The variable was designated PSN J14030581+5416254 when posted on Aug. 24.99 on the Central Bureau's TOCP webpage by Bishop and is here designated SN 2011fe based on the spectroscopic report below by Nugent et al. A preliminary spectrum obtained on Aug. 24 UT with FRODOSPEC on the Liverpool Telescope indicates that 2011fe is probably a very young type-Ia supernova; broad absorption lines (particularly the Ca II infrared triplet) are visible. The presence of an H-alpha feature is confidently rejected.