Astronomers using the Spectro-Polarimetric High-contrast Exoplanet Research (SPHERE) instrument on ESO’s very large telescope have discovered and directly imagined a giant exoplanet orbiting the young star YSES 2.
A direct image of the massive exoplanet YSES 2b and its host star. Image credit: ESO / SPHERE / VLT / Bohn et al.
YSES 2 is a K1-type star located 359 light-years away in the southern constellation of Musca.
Also known as TYC 8984-2245-1, the star is only 13.9 million years old and belongs to a nearby group of stars called the Scorpius-Centaurus association.
The new planet, called YSES 2b, has a mass about 6.3 times that of Jupiter and orbits its parent star at a distance of 115 AU (astronomical units).
“YSES 2b is an important addition to the sparsely populated group of giant orbiters,” said astronomer Alexander Bohn and colleagues Leiden.
Astronomers have detected the planet using the SPHERE instrument on ESO’s very large telescope.
The discovery was made as part of the Young Suns Exoplanet Survey (YSES), which aims to detect and characterize the planetary mass companions of solar-type host stars in the Scorpius-Centaurus association.
“The long distance from YSES 2b to its star is a puzzle because it does not appear to fit any of the two best-known models for the formation of large gaseous planets,” the researchers said.
“If the planet had grown in its current location, far from the star through basic accretion, it would be too heavy because there is not enough material to create a huge planet at this great distance from the star.”
“If the planet was created by so-called gravitational instability on the planet’s disk, it doesn’t seem to be heavy enough.”
“A third possibility is for the planet to form close to the star through basic accumulation and then migrate outward.”
“Such a migration would, however, require the gravitational influence of a second planet, which researchers have not yet found.”
“By investigating more Jupiter-like exoplanets in the near future, we will learn more about the processes of the formation of gas giants around Sun-like stars,” Bohn concluded.
The discovery is reported in a journal paper Astronomy and astrophysics.
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Alexander J. Bohn et al. 2021. The discovery of a planet with direct images to the young solar analogue YSES 2. A&A 648, A73; doi: 10.1051 / 0004-6361 / 202140508