Young moving stellar groups are the best targets for direct imaging of exoplanets and four massive Jupiter-like planets have been already discovered in the nearby young beta Pictoris moving group via high-contrast imaging. In a new study, astronomers analyzed 30 stars in this stellar group and found that 20 of them might potentially host a Jupiter-like exoplanet on stable orbit. Considering incompleteness in observations, their results suggest that Jupiter-like planets may be more common than previously found.
An artist’s impression of the giant exoplanet Kepler-1704b. Image credit: Sci.News.
Models predict that giant planets should easily form around solar-type stars, but until now not many have been found.
Previous research has suggested that the Solar System may be unusual because less than 20% of solar-type stars are orbited by Jupiter-like planets.
However, these planets may be much more common in young moving stellar groups.
Four massive Jupiter-like planets have been already discovered in the beta Pictoris moving group (BPMG) — a group of stars which is located relatively near Earth — using a technique called high-contrast imaging.
Young moving stellar groups are strong targets for direct imaging of exoplanets, and are important for stellar formation and evolution, and planet-forming circumstellar disk evolution studies.
Four other planets have also been suggested using high-precision astrometry by ESA’s Gaia satellite.
“One of the main questions in the field of extrasolar planets is how common are planetary systems similar to our own,” said Dr. Raffaele Gratton, an astronomer with the INAF-Osservatorio Astronomico di Padova, and colleagues.
“Very different answers have been proposed so far, none of which are entirely satisfying.”
“Our Solar System, beyond the so-called ice line (at about 3 AU) where ice particles can survive disruption by star irradiation, is dominated by giant planets.”
“Jupiter lies at 5.2 AU from the Sun. We call Jupiter-like giant planets those objects with masses larger or equal than one Jupiter mass lying at a distance from their stars between 3 and 12 AU (roughly from one to a few times that of the ice line).”
In the new research, Dr. Gratton and co-authors analyzed 30 stars in BPMG using stellar mass-planetary distance distributions, which are widely used to discuss planet formation scenarios.
They found that 20 of them might host a Jupiter-like planet, as their orbits would be stable.
They suggest that Jupiter-like planets may be more common than previously found, at least in small star-forming regions.
“Our analysis suggests that the formation of Jupiter-like planets around stars with masses over 0.8 solar masses, at least for environments such as the BPMG, is common,” they said.
“This is indeed a prediction of the core-accretion models.”
The team’s paper was published October 17, 2023 in the journal Nature Communications.
_____
R. Gratton et al. 2023. Jupiter-like planets might be common in a low-density environment. Nat Commun 14, 6232; doi: 10.1038/s41467-023-41665-0
