These emerging stars are surrounded by gas and dust discs, called “protoplanetary discs”, in which the planets are formed.
Inside, crystalline minerals containing silicon monoxide (SIO) can be condensed at extremely high temperatures.
Over time, they aggregate, winning in size and in mass to form “planetésimals”, the first solid parts of the planets.
In our solar system, these crystalline minerals, which then gave birth to planets like the earth or the nucleus of Jupiter, were trapped in old meteorites. Let astronomers use to date the start of the formation of our corner of the Milky Way.
By observing the disc around Hops-315, the study authors managed to find evidence that these hot minerals start to condense them.
Their results show that the SIO is present around the young star in the gas state as well as inside these crystalline minerals, which suggests that it has only been starting to solidify.
“This process has never been observed before in a protoplanetary disc, nor nowhere else outside our solar system,” said Melissa McClure.
These minerals were identified for the first time using the James Webb space telescope (JWST). Then scientists observed the system with the ESO ALMA instrument in Chile, to determine the exact origin of the chemical signals.
They discovered that these came from a small portion of the disc around the star, equivalent to the orbit of the asteroid belt that surrounds our sun. Which makes HOPS-315 a mirror of our own past.
“This system is one of the best we know to explore some of the processes that have occurred in our solar system,” says Merel Van’t Hoff, professor at the University of Purdue (United States) and co-authority of the study.