Astronomers have reported on the possible birth of a planet from the matter of a dead star.
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- Astronomers have reported on the possible birth of a planet from the matter of a dead star.
Astronomers have discovered signs of a planet that could have formed from matter ejected by the star before its transformation into a white dwarf. If the hypothesis is confirmed, it will be the first known example of a second-generation planet in such a stellar remnant. Details can be found in the Izvestia article.
What was found in the atmosphere of a white dwarf
A white dwarf is a dense remnant of a star that has exhausted its fuel. It can attract the matter of the surrounding planets and their debris. By the chemical composition of this material, scientists determine which objects are nearby.
Niobium was particularly prominent. In the matter entering the star, its content relative to calcium turned out to be more than a thousand times higher than the solar ratio. According to the team, niobium was first detected in the atmosphere of a white dwarf.
This composition, according to the authors, indicates a substance enriched in heavy elements even inside the dying star.
How could a new planet appear
Scientists suggest that the matter ejected by the star formed a disk, from which a gas giant subsequently formed. Such worlds are called second generation planets.: they appear after the final stages of the star's evolution.
"It's a bit like discovering a planet that has risen from the ashes of the very star it orbits," said Jamie Williams, a researcher at the University of Warwick.
A stellar companion was probably needed to form the disk. Its gravitational influence could keep some of the ejected matter in the system. In a single star, this material is usually dispersed in space.
Why does the opening still require confirmation?
Additional evidence was provided by observations of the NASA TESS satellite. He registered faint changes in brightness with a period of about 4.4 days. The signal is consistent with the presence of a nearby gas giant about the size of Jupiter.
According to the proposed model, intense radiation from a white dwarf causes the planet to lose its atmosphere. Some of the escaping gas enters the star, explaining its unusual chemical composition.
However, the object remains a candidate planet for now. The authors also admit another option: a previously existing planet could receive a new atmosphere from the matter ejected by the star. Then its core would belong to the first generation, and the gas shell to the second.
The researchers propose to look for similar systems based on the increased content of carbon and heavy elements in the atmospheres of white dwarfs.
Переведено сервисом «Яндекс Переводчик»
