Brightest Supernova Seen May Be Black Hole Eating A Star
A recent luminous outburst that had scientists thinking of a bright supernova may, in fact, be an explosive death of a star that has been torn apart by a giant black hole.
To show the difference, supernovae are explosions that happen when stars die as they run out of fuel or gain a sudden influx of material that allows them to outshine other stars in their galaxies, and this does not seem to be the case in the recent discovery.
Space.com reported that scientists discovered a rare class of supernovae -- called superluminous supernovas -- that are explosions up to 100 times brighter than others, but only account for less than one-thousandth of all supernovas that happen.
In analyzing data from the All-Sky Automated Survey for Supernovae (ASAS-SN) in January, scientists discovered an explosion (ASASSN-15lh) in the sky bordering the southern constellations Indus and Tucana. It gave off about 570 billion times more light than Earth's Sun at its peak. Initially classifying it as a superluminous supernova, researchers now believe it to be a death of a star caused by a supermassive black hole that has torn it apart.
There are factors that led to the change in its classification. For instance, it appeared in a large, reddish galaxy, which is not a place for superluminous supernovae, according to the study's lead author, Giorgos Leloudas, at the Weizmann Institute of Science in Rehovot, Israel. This kind of galaxy lacks young, massive stars that can give rise to such dazzling explosions.
The new classification is not final, though. According to The Verge, astronomers say that pulverizing a passing Sun-like star (an event known as a tidal disruption) could have sent debris colliding into each other, but the black hole will also have to be spinning super fast to disrupt it. "Even with all the collected data we cannot say with 100 percent certainty that the ASASSN-15lh event was a tidal disruption event," Leloudas shared. "But it is by far the most likely explanation."