The secret of the birth of a ‘gas planet’ 9 times larger than Jupiter

<초거대 가스행성 상상도. 사진=미 항공우주국(NASA), 유럽우주국(ESA), 우주망원경연구소(STScl) 조셉 옴스테드>

The Hubble Space Telescope has discovered a supermassive gas planet that is forming in a new way rather than a standard model.

The ‘core accreption’ model has been proposed as a standard for large gas planets like Jupiter, which are formed by accreting gas giants ranging from dust grains to rocks by colliding and accumulating a core larger than Earth. . Examples are Jupiter or Saturn formed at 5 to 10 times the Sun-Earth distance (1 au).

<주별 주변으로 공전하고 있는 초거대 가스행성 ‘마차부자리 AB b’ 프로토타입이 보인다. 2007년과 2021년 사진을 비교해 시계 반대방향으로 움직인다는 사실을 알아냈다. 사진=미 항공우주국(NASA), 유럽우주국(ESA), 스바루 망원경 천문대 테인 커리>

However, recently, a research team at the National Astronomical Observatory in Japan has captured a supermassive gas planet that is forming under conditions where there are not enough planets to form a gigantic nucleus and presented it as proof of the ‘disc instability’ hypothesis. The results of this study were published in the scientific journal ‘Nature Astronomy’.

The disk instability hypothesis is a theory that it may have been formed through the process of disintegration and fragmentation of a gas disk due to gravitational instability. Simply put, it is a top-down theory that protoplanets were formed when clouds of gas were pulled together by gravity. This contradicts the nuclear accretion hypothesis, which is a bottom-up central growth model.

The gas planet discovered by Hubble is AB Auriga b, about 531 light-years from Earth. It is forming in the disk of a protoplanetary system around a young star.

This gas planet orbits the young star ‘AB Auriga’, which is only about 2 million years old, at a distance of about 13.7 billion km. The research team explains that it takes a long time to form with the standard model, nuclear accretion theory.

<주별 ‘마차부자리 AB’를 중심으로 공전하며 형성 중인 초거대 가스행성 ‘마차부자리 AB b’. 공전 반지름은 해왕성 공전 궤도(점선)의 두 배에 이른다. 사진=스바루 천문대>

The research team led by Dr. Thein Curry came to this conclusion by comparing the appearance of AB Auriga b as seen using the Hubble Space Telescope and the Subaru Telescope in Hawaii. In the wake of the planet, a vortex of disk material, a phenomenon previously predicted by the disk instability hypothesis, was also observed.

“Nature is smart and can form planets in a variety of ways,” said Curry. He added, “This study was possible thanks to the Hubble Telescope, which has accumulated data for a long time.”

Reporter Seo Hee-won, Electronic Newspaper Internet ([email protected])