On Aug. 17, the Advanced Laser Interferometer Gravitational-Wave Observatory, or LIGO, detected a gravitational wave signal that was consistent with the merger of two stars for the first time.
Before that, scientists had detected only black hole mergers. Ryan Chornock, an OU assistant professor in physics and astronomy, was among the team of scientists that observed the aftermath of a burst of gravitational waves and the corresponding explosion, or kilonova, following the merging of two neutron stars.
“Theses discoveries are made possible by very large teams,” Chornock said. “LIGO collaboration itself has something like a thousand people involved.”
LIGO scientists won the Nobel Prize in physics in 2017 after they announced they had recorded gravitational waves following the collision of two black holes. Famed physicist Albert Einstein had predicted the existence of such waves, but LIGO scientists were the first to record them.
“It’s significant, because now — for the first time — we can actually see with our telescopes and study the usual ways that we’ve been doing for a long time and connect the properties for the source to the gravitational wave signals that we saw,” Chornock said.
He said a challenge for scientists is that gravitational waves may show that an event has occurred, but not where in the universe it happened.
“It turned out to be a rather much easier time this time around because they were able to limit it to an area that you wouldn't really survey, whereas the previous couple events were these huge sky areas,” Douglas Clowe, an associate professor of physics and astronomy, said.
Chornock was in Chile when his team at the observatory detected the neutron star merger using a dark energy camera.
Clowe said Chornock could not discuss his research before the paper on the event was published. Madappa Prakash, a physics and astronomy professor, said even though he and Chornock are close friends, Chornock did not tell him about his findings.
“He’s my best buddy, but he never told me, because they have their own circle,” Prakash said.
Prakash said Chornock’s findings are significant because they add to the evidence supporting Einstein’s theory of the activity.
“So now that we learned Einstein was right, Einstein's theory is essentially one of geometry,” Prakash said. “You can't do much physics with just black holes mergers. When neutron stars have merged, life begins to get exciting.”
Chornock said the event provides some of the strongest evidence that a neutron star collision has the capability of producing heavy elements such as lead, uranium and gold.
