By Ron Cowen
WASHINGTON — Astronomers may have detected smoke signals generated by a group of supernovas that blew up when the universe was less than 1.2 billion years old. If correct, the researchers have detected what would be one of the earliest known signs of supernova-produced dust in the universe, and the earliest dust detected thanks to a gamma-ray burst.
The exploding stars are too faint and lie too far away to be seen directly. But the smoke, or stardust, they produced when they erupted now appears to have been detected. The brilliant afterglow of a much more powerful type of eruption, a gamma-ray burst, has revealed the dust’s existence, a new analysis shows.
The new finding “is exciting because gamma-ray bursts are showing themselves as a unique probe of the early universe that really hadn’t been considered,” said Joshua Bloom of the University of California, Berkeley, reporting the work January 4 at the winter meeting of the American Astronomical Society. “We can now measure how matter in the [young] universe converts from stars into stardust,” the raw material for the next generation of stars, he added.
Bloom, Daniel Perley of UC Berkeley and their colleagues also posted the findings online. Stardust is known to absorb visible and ultraviolet light and to re-emit the light at longer, infrared wavelengths.