Astronomers have observed expanding remnants of a supernova that exploded 11,000 years ago, but are puzzled by some aspects of this supernova remnant which do not seem to follow trends shown by other supernova remnants. This article offers an explanation for observed differences by proposing that a quark nova exploded after the original supernova. The theory suggested in this paper could help astronomers explain these anomalies and advance this field of study.

http://www.raa-journal.org/raa/index.php/raa/article/view/1853