Astronomers Hope X-Ray Bursts Are Signs of Supernovas to Come

Astronomers are closely watching three sections of the sky following three short but powerful X-ray bursts that may be harbingers of supernovas that could occur in the next few days.

A supernova results when a big star ends its life in an explosive gravitational collapse so complete that it traps the brilliant flashes of light produced in the event for several days.

Supernovas release bursts of neutrinos before the light is emitted, but it is not known whether they also emit X-rays. Scientists hope that the recently observed bursts might also be precursors of the powerful flash that signals the death of a star.

The first two X-ray bursts, lasting only seconds apiece, were observed Sept. 12 and 16. They were followed by a more powerful burst Sept. 24. This one appeared to be on the cusp between an X-ray flash and a full-fledged gamma-ray burst.

All three events were detected by NASA’s High Energy Transient Explorer-2 satellite.

“Each burst has been beautiful,” said astronomer George Ricker of Massachusetts Institute of Technology. “Depending on how these evolve, they could support important theories about supernovas and gamma-ray bursts.”

Astronomers have never witnessed the birth of a supernova, and suspect that such an observation could provide valuable information about the workings of the universe.

One effort to observe the early stages of a supernova is the recent creation of the SuperNova Early Warning System, or SNEWS. SNEWS works by linking neutrino observatories around the world to a central computer at Brookhaven National Laboratory in New York.

The detection of a sudden burst of neutrinos would alert astronomers that a supernova was imminent and would tell them where to point their telescopes.