2011CBET.2642....1A

R. Amanullah, A. Goobar, J. Johansson, J. Joensson, E. Moertsell, J. Nordin, K. Paech, T. Riehm, and V. Stanishev, Physics Department, Stockholm University, report the discovery of a type-Ia supernova (at AB magnitude i = 20.3) that was first detected on 2010 May 17.944 UT with the 2.5-m Nordic Optical Telescope (NOT) on the island of La Palma. The new object, designated SN 2010lw, is located 0".77 west and 0".35 north of its presumed host galaxy, which is one of the members of the galaxy cluster Abell 1689 and is located at R.A. = 13:11:21.618, Decl. = -1:21:41.57 (equinox 2000.0); thus, 2010lw is located at position end figures 21s.567, 41".22. Additional AB magnitudes for 2010lw: 2010 Apr. 10, [24.3 (i-band; 5-sigma; NOT/MOSCA); May 20, g = 20.9, r = 20.4, i = 20.5; June 12, g = 22.8, r = 21.5, i = 21.2; July 11, A spectrogram (range 400-770 nm) was obtained on 2010 May 21 by Joel Johansson using the NOT (+ ALFOSC), showing clear type-Ia-supernova features (Ca H and K, Fe, S, and Si II 635.5-nm). The spectrum matches a type-Ia-supernova template at day 12 for z = 0.189 (the redshift of the host galaxy). The template epoch (day 12) is consistent with the lightcurve dating.