Researchers learn more about the strongest gamma ray ever detected

On Oct. 9, a pulse of intense radiation swept through the solar system; it was so exceptional that astronomers quickly dubbed it the BOAT – the brightest of all time.

University of Arizona astronomers have now joined an international effort to study the aftermath of the brightest flash of gamma rays ever observed. Two research teams at the University of Arizona are re-analyzing the data to better understand what causes these outbursts of cosmic proportions. Papers describing the results will appear in The Astrophysical Journal Letters.

Kate Alexander, Assistant Professor at the University of Arizona’s Department of Astronomy and Steward Observatory, co-authored one of the papers. “You would expect one of this magnitude about once in 10,000 years,” she said.

“A gamma ray burst is a very large flash of gamma ray radiation, and we think that it is caused when a massive star explodes at the end of its life and collapses to form a black hole,” said Alexander.

Alexander explained that the gamma ray burst can first be detected as a flash of light that lasts just a few seconds. However, the interaction with the space that it passes through can last much longer.

“Even though this event was discovered last fall, we are still able to see it with specialized telescopes today,” said Alexander. “We are still watching this, what we call the afterglow light, as it interacts.”

The gamma ray burst was first discovered by several different satellites orbiting the Earth. The satellites, operated by NASA as well as other nations, detected such a bright burst of gamma rays that it caused the sensors to overload.

“It was so bright, satellites that weren’t even designed to look for it, saw it,” said Alexander.