ALMA Telescope Spots Supernova Dust Factory

Astronomers have spotted the remains of a recent supernova brimming with freshly formed dust with the help of the Atacama Large Millimeter/submillimeter Array (ALMA) telescope. The findings could help explain how many galaxies acquired their dusty, dusky appearance.

Galaxies can be remarkably dusty places, and supernovae are thought to be a primary source of that dust--especially when it comes to the early universe. Yet direct evidence of a supernova's dust-making capabilities has been hard to come by--until now. The new observations from ALMA show the dust in this supernova.

This particular supernova is called Supernova 1987A. Located in the Large Magellanic Cloud, it's about 160,000 light years from Earth. It's actually the closest observed supernova explosion since Johannes Kepler's observation of a supernova inside the Milky Way in 1604.

"We have found a remarkably large dust mass concentrated in the central part of the ejecta from a relatively young and nearby supernova," said Remy Indebetouw, one of the researchers, in a news release. "This is the first time we've been able to really image where the dust has formed, which is important in understanding the evolution of galaxies."

Astronomers predicted that as gas cooled after a cosmic explosion, large amounts of dust would form as atoms of oxygen, carbon and silicon bonded together in the cold central regions of the remnant. Yet earlier observations of SN 1987A with infrared telescopes detected only a small amount of hot dust. With ALMA, though, the researchers were able to image the far more abundant cold dust.

"SN 1987A is a special place since it hasn't mixed with the surrounding environment, so what we see there was made there," said Indebetouw, one of the researchers, in a news release. "The new ALMA results, which are the first of their kind, reveal a supernova remnant chock full of material that simply did not exist a few decades ago."

The findings reveal a bit more about galaxy evolution, and may show why some galaxies are so dusty. Supernovae likely created most of the dust in the early universe and now, scientists have direct evidence to support that theory.

The findings are published in the Astrophysical Journal Letters.