Feb 13, 2017
An Exploding Star Is Caught in the Act
The resulting supernova explosion seeds a galaxy with iron, silicon and other elements forged by the nuclear fusion of hydrogen and helium in the doomed star's core.
Thanks to a bit of serendipity and quick work by astronomers, the death of a massive star on Oct. 6, 2013 did not go unnoticed.
An automated wide-angle sky survey at California's Palamar Observatory spotted a very young supernova in the spiral galaxy NGC 7610, located about 160 million light years away.
Realizing the supernova wasn't in the previous night's scans, astrophysicist Ofer Yaron at Israel's Weizmann Institute of Science and colleagues alerted fellow astronomers to pick up the hunt.
By coincidence, California Institute of Technology astronomer Dan Perley was making spectroscopic observations with the Keck telescope in Hawaii and turned his attention to the newly found supernova. He was able to collect data and analyze what had been expelled from the star in the year or so before its demise.
"Direct observation of these processes is challenging, as stars in these brief final stages are rare," Yaron and colleagues write in a paper published in this week's Nature Astronomy.
The scientists discovered that in the year before the star burst, it had ejected the equivalent of 1,000 Earth masses.
Follow-up observations by NASA's Swift satellite in X-ray and ultraviolet light enabled the team to map the distribution of the material ejected before the star went supernova.
"Catching and being able to obtain significant follow-up observations of a supernova explosion as early as possible, in its very youth (first minutes to hours after explosion), is crucial for shedding light on our understanding of both the latest stages of evolution of massive stars and understanding of the explosion mechanisms themselves," Yaron wrote in an email to Seeker.
Read more at Discovery News