First-ever glimpse of the dawn of a solar system

The dawn of a new solar system has been observed for the first time, captured just as the first grains of hot minerals that will form the planets are condensing: everything orbits around a newborn star , called HOPS-315 , which is located about 1,300 light-years away from us and which shows many characteristics similar to those our Sun also had.

The discovery is the result of observations from the European Southern Observatory's ALMA telescope in Chile and the James Webb Space Telescope of the European, Canadian, and United States space agencies. The results, published in the journal Nature, open a new window into the past of our Solar System.

"For the first time, we've identified the earliest time planetary formation begins around a star other than the Sun," says lead author Melissa McClure of Leiden University in the Netherlands. The results are like "a snapshot of the newborn solar system ," adds Merel van 't Hoff of Purdue University in the USA. "We're looking at a system that resembles how our own solar system looked when it was just beginning to form."

Around newborn stars, astronomers often observe disks of gas and dust known as protoplanetary disks, from which new planets are born. Although young disks containing massive, Jupiter-like baby planets have been observed before, "we've always known that the first solid components of planets, or planetesimals, must have formed further back in time, at earlier stages," McClure emphasizes. With this new discovery, astronomers have gathered evidence that these hot minerals are beginning to condense in the disk around HOPS-315 .

The results show that silicon monoxide is present in a gaseous state around the newborn star , as well as within these crystalline minerals , suggesting that it is just beginning to solidify . "This process has never been observed before in a protoplanetary disk, nor anywhere outside the Solar System," says Edwin Bergin of the University of Michigan. These minerals were identified using the James Webb Space Telescope , while ALMA allowed them to be located in a small region of the disk around the star, equivalent to the orbit of the asteroid belt around the Sun. For this reason, the disk of HOPS-315 represents a valuable model with which to study our own cosmic history.