(ORDO NEWS) — The Hubble Space Telescope has photographed the youngest known protoplanet. It resembles Jupiter, but was formed in a completely unconventional way for gas giants. The discovery helps explain the history and features of some exoplanets.
The protoplanetary disk is a cloud of dense gas rotating around a young star, in which the formation of planets takes place. The star AB Aurigae, observed by NASA’s Hubble Space Telescope, is only about two million years old.
About the same amount was the solar system when the planets formed in it. In images of the disk of the star, scientists have discovered the youngest known protoplanet, called AB Aurigae b. The discovery was also that this gas giant was formed in an unusual way for such planets.
According to the most popular hypothesis, gas giants are formed in the process of “core accretion”. First, particles of material collide and stick together in the protoplanetary disk, forming a rocky core, which then slowly accumulates gas from the surrounding disk.
While this model works well for planets in the solar system, it is difficult to explain the appearance of gas giants that orbit at great distances from their stars.
Another hypothesis, which up to this point has not received confirmation in observations, explains the formation of gas giants by “instability of the protoplanetary disk.” According to her, as the disk cools, gravity causes it to quickly disintegrate, and matter to form objects of planetary mass.
The scientists compared data from Hubble’s near-infrared spectrographs and cameras with observations from the SCExAO planetary imaging instrument on the 8.2-meter Japanese Subaru Telescope at the Mauna Kea Observatory in Hawaii.
The fact that the protoplanetary disk of AB Aurigae is almost completely turned towards the Earth made it possible to obtain detailed images. AB Aurigae b is about nine times as massive as Jupiter and orbits its star at a distance of 13.8 billion kilometers.
This is more than twice the distance from Pluto to the Sun. At such a distance, it would take a very long time for such a huge planet to form by core accretion. Therefore, the scientists concluded that AB Aurigae b formed as a result of disk instability.
The hypothesis was confirmed by the fact that the shape of the nearby spiral gas structures corresponds to models in which the planet is formed as a result of the gravitational collapse of the surrounding matter.
The discovery helps explain the formation of many distant gas exoplanets. In addition, understanding the formation of planets like Jupiter will help to learn more about the history of the solar system.
The results of the work pave the way for future studies of the chemistry of protoplanetary disks, including the recently launched James Webb Telescope.
Contact us: [email protected]