Spectra from just hours after blast provide details of star’s last days
Astronomers have caught a star exploding just hours after light from the eruption first reached Earth. Measurements of the blast’s light suggest that the star rapidly belched gas in the run-up to its demise. That would be surprising — most scientists think the first outward sign of a supernova is the explosion itself.
“Several years ago, to catch a supernova early would mean to detect it at several days, a week, or maybe more, after the explosion,” says astrophysicist Ofer Yaron of the Weizmann Institute of Science in Rehovot, Israel. Now, he says, “we talk about day one." Although previous supernovas have been seen this early, the new observation is the earliest one with a spectrum — an accounting of the emitted light broken up by wavelength — taken six hours after the explosion, Yaron and colleagues report online February 13 in Nature Physics.