Discover an exoplanet in formation far from its star
Astronomers determined that a planet is growing at 12,000 million km from its star, challenging current theories of planet formation.
A team of astronomers, led by John Debes, Institute of Space Telescope Science in Baltimore, Maryland, discovered a planet in formation no less than at a distance of 12.1 billion miles from its host star (something like the twice the distance from the Sun is Pluto). The team of astronomers used the Hubble Space Telescope and NASA finding – released on June 14 – can challenge current theories of planet formation.
The star system TW Hydrae
Of the nearly 900 extrasolar planets have been confirmed to date, this is the first that is in such a great distance from its star. The supposed planet is orbiting the red dwarf tiny TW Hydrae, located 176 light years away from Earth in the constellation Hydra. The vision of the Hubble detected a mysterious void in a large protoplanetary disk of gas and dust swirling around TW Hydrae. The gap is 3.1 billion km wide and the disk is 66 billion kilometers wide.
The presence of the gap was probably caused by the growth of a planet that is not seen but is gravitationally sweeping the material and carving a path in the disk, such as a snow plow. It is estimated that the planet is relatively small, 6-28 times more massive than Earth. Its wide orbit means that it moves slowly around its host star.
Planets are thought to form over tens of millions of years, a slow build, but persistent dust, rocks and gas of the protoplanetary disk. This planet at that distance from its star, you must take more than 200 times longer to form than Jupiter, as their distance from the star makes its orbital speed is much slower and also by the lack of material in the disk at that distance. Instead Jupiter is about 800 million kilometers from the Sun and formed in about 10 million years. TW Hydrae is a young star of only 8 million years, so according to this theory, it was unlikely to have a planet.
Collapse theory of planet formation
However, there is a planet formation theory suggests that alternative a piece of the disc becomes gravitationally unstable and collapses on itself. In this sense, the planet could form more quickly, in just a few thousand years. “If we can really confirm that there is a planet there, could connect their characteristics with measurements of the properties of the gap,” Debes said, adding: “That could add to the planet formation theories as to how it can be a planet so far. ”