New stellar explosion lights up sky

The detonation was many times brighter than a supernova

discovered a new type of stellar explosion being driven by an XQNQRZQ HQHUJ\ VRXUFH 7KH DVK ZDV XS to 100 times brighter than the average supernova and lasted just 16 days.

The outburst, called AT2018cow or ‘The &RZ ZDV UVW VSRWWHG E\ WKH $7/$6 $OO 6N\ 6XUYH\ RQ -XQH EXW ZDV only recently announced after months of detailed follow-up observations by telescopes around the world, including the 9HU\ /DUJH $UUD\ 9/$

“This was an incredibly luminous event, brighter than almost any supernova we’ve ever seen before,” says Daniel Perley from /LYHUSRRO -RKQ 0RRUHV 8QLYHUVLW\ ZKR took part in the study. “The Cow appeared and faded away very quickly: so quickly that existing supernova models can’t properly explain it,” says Perley. “It must be a new type of extremely energetic, explosive event.”

Astronomers are currently debating exactly what The Cow is, and what mechanism might be driving it. Initially, the explosion was thought to be a supernova, but its brightening pattern and spectra do not resemble the typical death throes of a star.

8QOLNH VXSHUQRYDH ZKLFK GLP VPRRWKO\ over time, this explosion faded unevenly, suggesting it was being ‘driven’ from within by some unknown, long-lasting power source that kept pumping energy into the material of the explosion as it expanded.

“If it is a supernova, then it is unlike any supernova we have ever seen,” says Anna Ho, from the California Institute of Technology, who led some of the follow-up studies of the event.

Another theory being considered is that it’s a large star being shredded by a supermassive black hole. However, the region in which The Cow detonated is not one in which astronomers would expect to QG EODFN KROHV RI WKDW VL]H

A third alternative is that the explosion is part of the birth of either a black hole or a rapidly rotating neutron star, called a magnetar.

“We know that black holes and neutron stars form when a star dies, but we’ve never seen them right after they are born,” VD\V 5DIIDHOOD 0DUJXWWL RI 1RUWKZHVWHUQ 8QLYHUVLW\ ZKR KDV DOVR VWXGLHG 7KH &RZ

Astronomers will continue to take new observations, and monitor the skies for signs of another example of this surprising new phenomenon.