http://www.nature.com/nature/journal/v447/n7146/full/nature05825.html

Link to nature article for Nature mag

A giant outburst two years before the core-collapse of a massive star


and

http://arxiv.org/abs/1111.2497

Link to arxiv link to Astronomy and Astrophysics

SN 2009E: a faint clone of SN 1987A