Rutgers professor aids in discovery of universe's brightest explosion
Some 500 million years after the Earth was first born, a massive star died, becoming the brightest object in its galaxy for the immediate future. That same supernova may actually be the brightest and most powerful explosion ever recorded.
In June 2015, researchers at Ohio State University, including two Rutgers alumnae, working for the All-Sky Automated Survey for SuperNovae (ASASSN) project noticed an incredibly bright object in the sky, said Saurabh Jha, an associate professor in the Department of Physics and Astronomy.
“ASASSN-15lh is the most luminous supernova ever discovered, more than twice as bright as the next most powerful explosion,” he said. “When the ASASSN team discovered this supernova in June 2015, they realized it was very powerful, but could not know if it was the most luminous supernova ever discovered until they knew its distance from us.”
Jha used the South African Large Telescope (SALT) to establish this distance, and soon scheduled some observations. They estimated the supernova’s distance to be 4 billion light-years away from Earth.
The event is 570 billion times as bright as Earth’s sun, according to CNN, and at least 20 times brighter than every star in the Milky Way galaxy.
It was “hundreds of times” as powerful as normal supernovae, Jha said.
“That proved it really was the most luminous supernova ever discovered,” he said.
A closer supernova with that brightness would be less powerful because of the distance, he said.
Further research is being done using SALT and the Hubble Space Telescope to determine what type of star became the supernova and what caused it to explode, he said. The scientists are also trying to determine what sort of materials are in the explosion itself.
“This is a very rare object,” he said. “We’ve observed thousands of supernovae, and this one is unique because of its exceptional luminosity. We didn’t think exploding stars could really get so bright.”
Data collected from the explosion nearly does not match the models for supernovae, he said.
“So even though it is far away, the fact that such a thing exists is interesting because it might be pointing out a new way that stars can live and die that we didn’t know about before,” he said.
Scientists are now looking for the center of the explosion, according to CNN. They have found a 10-mile wide object that they trying to focus on.
“Exploding stars mark the end of the lives of massive stars, so by studying supernovae like this one, we can learn more about how stars live and die,” he said.
If more supernovae like ASASSN-15lh exist, they can also also help scientists explore more of the universe, he said.
This can further help researchers understand what distant galaxies looked like in the distant past.
“Normal supernova explosions would be too faint to see at extreme distances,” he said. “Analogues of ASASSN-15lh might still be visible, perhaps providing a new way to study the distant Universe as it was a long, long time ago.”
Nikhilesh De is a School of Engineering junior. He is the news editor of The Daily Targum. Follow him on Twitter @nikhileshde for more.