The Hubble Space Telescope has taken a direct picture, the main figure of which is a Jupiter-like protoplanet, which is forming right now in a very unusual, intense and rapid way, which is fundamentally different from the way the vast majority of planets in the universe are formed. This discovery is the first direct evidence of the hypothesis that has existed for some time about the possibility of the formation of Jupiter-like planets due to the process of so-called “instability of the protoplanetary disk.
The discovered protoplanet at the stage of formation is still confined inside the protoplanetary disk, a disk of dust and gas surrounding a young star, up to 2 million years old. According to the leading theory on planet formation, almost all planets grow out of small formations that, as material accumulates, acquire their own gravity and attract more matter, whose particles collide, heat up and fuse. And in the end, the formed nucleus begins to slowly attract gas from the surrounding space, gradually turning into a gas giant.
In contrast to the method of planet formation described above, the process of “protoplanetary disk instability” is much faster on a cosmic time scale. The large protoplanetary disk around the star cools, and it disintegrates into several massive fragments under the influence of the star’s gravity and its own gravitational forces. The fragment, which is under the right conditions, then continues to shrink and becomes a planet, eventually.
The planet in question at the beginning is called AB Aurigae b, it is now nine times larger than Jupiter and orbits its star at a distance of 13.84 billion kilometers, more than twice the distance between the Sun and Pluto. At this distance, it would take much longer for a planet to form through the traditional growth process to gain its current mass. And given this fact, scientists have concluded that the planet AB Aurigae b was formed by a process of “protoplanetary disk instability.”
The protoplanet AB Aurigae b was detected and studied using two Hubble Space Telescope Imaging Spectrograph and the Near Infrared Camera and Multi-Object Spectrograph instruments. The scientists also used a data package obtained with the SCExAO instrument of Japan’s 8.2-meter Subaru Telescope, located in Hawaii. And the fact that the protoplanetary disk with the planet is located almost perpendicular to the plane toward Earth contributed to all this.
Also, observations at different wavelengths on the protoplanet AB Aurigae b have brought their share of success in discovering and studying it, plus 13 years of Hubble telescope observations have made it possible to determine and calculate the parameters of this planet’s orbit.
“This discovery provides strong evidence that some of the gas giants may form through the mechanism of ‘protoplanetary disk instability'” – write the researchers,” “The main aspect of this process is the forces of gravity, the effects of which will cause all the remnants of the young star formation process to turn into planets after a while.
