Ancient Stardust Sheds Light On First Stars In Universe

A massive amount of glowing stardust in a galaxy may have been seen shortly after the formation of the universe, as detected by a team of astronomers from UCL. This discovery gives new insights regarding the birth and deaths of the very first stars ever to be seen.

Phys.org noted that the galaxy is the most distant object ever to be observed by the Atacama Large Millimeter/submillimeter Array (ALMA). It was seen when the universe was only about 4 percent of its present age, which put it at around 600 million years old. This was around the same time that the first stars and galaxies were formed.

The team that was led by Dr. Nicolas Laporte of the UCL Physics and Astronomy department noted that it was surprised to find the youthful galaxy A2744_YD4 containing an abundance of interstellar stardust that was formed by the deaths of an earlier star generations. "Not only is A2744_YD4 the most distant galaxy yet observed by ALMA, but the detection of so much dust indicates early supernovae must have already polluted this galaxy," Laporte said.

The cosmic dust that may have contaminated the said galaxy is mainly composed of silicon, carbon and aluminum. It can be as small as a millionth of a centimeter across. The chemical elements are said to have been forged inside stars and are scattered across the cosmos as they die in spectacular supernova explosions. The newly discovered dust is said to be plentiful and has since become a key building block in star formation in the early universe. But before the first generations of stars died out, such cosmic dust has been scarce.

EarthSky also noted that star explosions can spread heavier elements into space, making them available for other parts of the cosmos -- or even planets like Earth. Thus, the Earth that people live on, as well as our very human bodies, are made of the same stuff as the stars in the universe.