2009IAUC.9092....1R

A. Rest, Physics Department, Harvard University, on behalf of the SuperMACHO collaboration, reports the discovery of a supernova (at "VR" magnitude 20.5) at z = 0.289 behind the Large Magellanic Cloud on images obtained on 2003 Dec. 13 with the Cerro Tololo 4-m Blanco telescope in the course of the SuperMACHO microlensing survey (Rest et al. 2005, Ap.J. 634, 1103). The object, designated SN 2003ma, faded by only 2.9 mag in I over the first 4.7 years following peak brightness (I = 19.7). It is located at R.A. = 5h31m01s.878, Decl. = -70o04'15".89 (equinox 2000.0), which is 0".1 south of its host galaxy. Spectroscopy obtained with the Gemini South telescope (+ GMOS) on 2003 Dec. 22.3 and with the Magellan Clay telescope (+ MagE) on 2008 Dec. 28.3 shows 2003ma to be a very luminous type-IIn supernova, similar to SN 1988Z (Turatto et al. 1993, MNRAS 262, 128). The 2008 spectrum shows an intermediate- width H_alpha line with a FWHM of 5800 km/s. Details will be given in a paper by Rest et al. (2009, Ap.J., submitted).