[Epoch Times News on May 3, 2021]The National Space Administration (NASA)Hubble Space Telescope(Hubble Space Telescope) recently captured a rare astronomical event, a planet about the size of Jupiter and still forming, it is absorbing material around a young star.
Brendan Bowler of the University of Texas Austin said: “We don’t know much aboutGiant planetHow is it formed. “This planetary system provides us with the first testimony of how matter accretes on a planet. Our results open up a new field for this research.”
Although astronomers have catalogued more than 4,000 exoplanets so far, so far, the telescope has only directly imaged about 15 exoplanets. Planets are so far away and small, they are usually just a point in the clearest picture.
The research team used Hubble’s latest technology to directly image the planet, opening up a new way for further exoplanet research, especially during the planet’s formation period.
This huge exoplanet is designated PDS 70b, orbiting the orange dwarf PDS 70. The orange dwarf is known to have two forming planets in a huge stellar disk surrounded by dust and gas. The system is located in the constellation Centaurus, 370 light-years from Earth.
“This system is so exciting because we can witness the formation of a planet,” said Zhou Yifan of the University of Texas at Austin. “This is the youngest real planet Hubble has ever directly imaged.” Said that at an age of about five million years, the planet is still absorbing material and accumulating mass.
Hubble’s sensitivity to ultraviolet light has a unique ability to observe the radiation produced by extremely hot gases falling on the planet.
“Hubble’s observations allow us to estimate the speed at which planets gain mass.” Zhou Yifan added.
By adding ultraviolet observations, the research team directly measured the planet’s mass growth rate for the first time. In about five million years, this planet has reached five times the mass of Jupiter. The current measured accretion rate has fallen sharply: if this accretion rate remains the same for about a million years, the planet will only increase by about 1/100 of the mass of Jupiter.
On Monday Fan and Bowler emphasized that these observations are only data in a short period of time, and more data are needed to determine whether the rate of planetary accretion mass is increasing or decreasing. “Our measurements indicate that the planet is at the end of its formation.”
The young PDS 70 system is full of primitive dust disks, which can provide fuel for planetary growth throughout the system. Planet PDS 70b is surrounded by its own disk of gas and dust, which is absorbing material from the dust disk of a huge star. The research team guessed that the magnetic field lines extend from the outer planetary disk down to the atmosphere of the exoplanet, and funnel matter to the planet’s surface.
“If this material enters the planet from the dust disk, hot spots will be seen locally.” Zhou Yifan explained, “These hot spots may be at least 10 times hotter than the Earth.”
These areas will glow violently under ultraviolet light.
These observations also provide clues to the huge gas planets that formed around our sun 4.6 billion years ago. Jupiter may have been produced by the accumulation of falling matter disks around it. Its main satellite will also be formed from the residue in the dish.
The results of this new study will be published in the Astronomical Journal on April 29, 2021.
Editor in charge: Lin Yan#