Victor Buso, an amateur astronomer, skyrocketed to fame after Sept. 20, 2016, when he became the first person to photograph the initial stages of an exploding star.
Focused on the NGC 613 spiral galaxy, located millions of light-years away, Buso’s visible light camera captured a series of short-exposure photographs. The camera picked up on a tiny emerging speck, which was later identified as a supernova’s shock breakout.
“Professional astronomers have long been searching for such an event, said UC Berkeley astronomy professor Alex Filippenko in a press release issued Wednesday. “It’s like winning the cosmic lottery.”
A supernova is a giant, dramatic explosion at the end of a star’s life. The resulting shock breakout occurs when the star core releases a supersonic pressure wave that heats gas on the star’s surface upon contact. The hot gas then emits light, which Buso’s camera detected.
Buso is the first to capture the “first optical light” of a normal supernova, which includes the before and after images of the shock breakout. His images have made significant contributions to recent research that was published in the Feb. 22 issue of the journal Nature and was co-authored by Filippenko.
The photographs provided observed brightness of the explosion, named SN 2016gkg, versus time.
“Data from the first moments can tell us the structure of the star just before it explodes, providing clues to how it explodes,” Filippenko said.
Filippenko and his supernova research team, which includes UC Berkeley undergraduate students and other faculty members, was part of a larger coalition of international astronomers that conducted observations of SN 2016gkg over the next two years. Their objective was to identify exploding stars and how they explode.
The team gathered the data, using three different types of telescopes: the Shane 3-meter telescope at the University of California’s Lick Observatory in California and the twin 10-meter telescopes at W. M. Keck Observatory in Hawaii.
With the data, Filippenko and his researchers identified the explosion as a Type IIb supernova, which means the star had lost most of its hydrogen prior to explosion. For a Type IIb supernova to occur, the star must be at least eight times the mass of our sun, according to Space.com.
Over the years, Filippenko and his team estimated that SN 2016gkg’s star had an initial mass about 20 times the mass of our sun and five times the mass of the sun prior to supernova explosion. The group’s discoveries contribute to the scientific community’s growing understanding of exploding stars, Filippenko said.
Filippenko’s research team continues to collect data on SN 2016gkg.
“We have shown that shock breakout can indeed be observed when a star explodes,” Filippenko said in regard to Buso’s photo contributions. “We hope to find more of them.”