Thu. Oct 6th, 2022

Astronomers have discovered a planet shrinking at a rapid rate

Gliese 3470b is counted among the so-called. hot neptuniumów and located at a distance of 97 light years from Earth. This is a rare class of planets. Of the 3869 confirmed extrasolar planets, only a handful are hot neptunians. These planets are similar to the hot Jupiters discovered earlierów – gas giantów, whichówhose orbits are very close to their parent star, often much closer than the orbit of Mercury in the Solar System. However, róThey are characterized by a lower mass and composition of.

Astronomerów has been puzzled for some time now by the fact that Neptune-sized planets are quite rare in close stellar orbits. So where did they go? Catalogs of exoplanets include a large number of hot planets the size of Jupiter. There are also quite a few planets slightly larger than Earth (so-called. super-Earths). Gliese 3470b (in skrócie GJ 3470b), whichóra is losing its atmosphere at a staggering rate, may provide an answer to this question.

Judging by how quickly this planet is disappearing, it lends weight to the hypothesis that the reason why theóhe discovery of so few hot neptuniansów is that they have shrunk to much smaller sizesów, about four times the size of Earth, and this is one of the most common types ofóin exoplanets discovered by the Kepler Space Telescope.

An international team is behind the discoveryół scientistsów directed by an astronomeróThe astronomers of the University of Geneva in Switzerland. Their research was published in the journal „Astronomy & Astrophysics”.

A few years ago, astronomers from the Geneva University using the Hubble Space Telescope'a discovered the hot Neptune GJ 436b, whichóry is losing its atmosphere. The rate of gas lossów does not threaten the planet’s existence, but suggested to the researchers that hot neptunians, które receive more energy from their star, they can evolve in a more dramatic wayób.

The thesis seems to be confirmed by the just-discovered hot neptunian GJ 3470b. It loses its atmosphere 100 times faster than GJ 436b. Both planets are located at distances of about 6 millionów kilometeróin from their stars. It is one-tenth the distance between Mercury and the Sun in our solar system. However, GJ 436b is orbiting wokół old, relatively cool red dwarf, and the star GJ 3470b is much younger, hotter and provides its planet with much more energy.

– This is the first time we have observed that a planet can lose its atmosphere so quickly. The rate is so high that it could affect its evolution – Said Vincent Bourrier first author of the study from the University of Geneva.

Hubble telescope's images revealed a huge cloud of hydrogen located in wok spaceół planets. Teamół researchers estimate that GJ 3470b has already been stripped of more than a third of its mass. According to them, hot neptunians are krótkotrwały class of planets. These objects are cratering and to a much smaller sizeów.

– We have discovered that planets can lose a significant amount of their mass – said David Sing of Johns Hopkins University, coóauthor of the publication. – GJ 3470b is losing more of its mass than any other planet, którra we have seen so far. In the next just a few billionóin years, up to half of the planet may disappear – added by.

In addition, although both planets have poresówn comparable size, GJ 3470b is less dense than GJ 436b, which means that its gravitational attraction is unable to hold the heated atmosphere.

– Atmospheric escape plays an important role in the observed lack of hot neptuniansów. GJ 3470b is one of the most extreme examplesóin a planet undergoing such a severe loss of mass. This has serious implications for its evolution and also affects our understanding of it – explained Bourrier.

Syndromeół hopes to expand its research using the James Webb Space Telescope, whichóry is scheduled to be launched in 2021. Its more sensitive instrumentation can detect escaping helium, which could expand the search for planets that have a problem with escaping atmospheres.