For the first time, astronomers were able to observe a supernova just a few hours after the explosion of a red supergiant star.
Their observations, described in a paper published in the journal Nature Physics, was made early enough to detect the debris and understand what occurred before the explosion.
"Direct observations of the very early and limited time window before the region is swept up by supernova ejecta can significantly improve our understanding of the late stages of stellar evolution of massive stars-composition, density profiles, and mass-loss history-particularly just before the supernova explosion," explained Ofer Yaron, an astrophysicist at the Weizmann Institute of Science in Israel and lead author of the paper, in an interview with Research Gate.
The astronomers first spotted the supernova during a robotic survey conducted at Palomar Observatory in Southern California on Oct. 06, 2013. Dubbed as SN 2013fs, the supernova occurred in the NGC 7610 galaxy, some 160 million light years away.
Further observation using X-ray and ultraviolet wavelengths showed that the supernova originated from red supergiant about 10 times the size of our sun. Additionally, the astronomers found a disk of matter circling the dying star. The astronomers believe that the disk was created just the year before the star exploded. Yaron explained that a dying star can rapidly send out tons of materials, losing a lot of its mass before exploding.
In a report from USA Today, Yaron likened the dying moments of the star to an incandescent light bulb, "which experiences a sudden stronger glow for several seconds just before the wire is torn, and the bulb ends its life."
Despite being observed just few years ago, the astronomers noted that the supernova actually occurred about 160 million years ago.
Yaron stressed out that every extra-galactic event being observed today have already occurred billion, if not millions, of years ago. The light being received by the telescopes today was emitted millions or billions of years in the past.