Astronomers were puzzled by the brightness of a supernova which exploded 9 billion years ago. Due to a gravitational lens caused by an intervening galaxy the supernova appeared to be 30 times brighter than expected, causing speculation that it was a new type.
http://www.sciencedaily.com/releases/2014/04/140424143659.htm
http://www.sciencedaily.com/releases/2014/04/140424143659.htm