For the first time ever, researchers have detected the presence of gas around a candidate massive planet, which orbits star AS 209. This is only the third time that a circumplanetary disk – the ring of material from which moons and maybe rings can form – has been discovered. The disk is estimated to be quite cold and to have a mass equivalent to 30 Earths.
As reported in The Astrophysical Journal Letters, the team used observations from the Atacama Large Millimeter/submillimeter Array (ALMA) to study this very young planetary system. The host star is believed to be just 1.6 million years old, making the planet one of the youngest ever discovered if confirmed. It is also over 29.92 billion kilometers (18.59 billion miles) from its star, challenging our standard view of planetary formation.
The team is now planning observations with JWST and hopes that these observations will confirm the existence of the planet without any doubt as well as deliver insights into what the system is like. One of the first targets of JWST was the atmosphere of exoplanet WASP-96b and the telescope found water vapor in it.
“The best way to study planet formation is to observe planets while they’re forming. We are living in a very exciting time when this happens thanks to powerful telescopes, such as ALMA and JWST,” lead author Jaehan Bae, a professor of astronomy at the University of Florida, said in a statement.
The AS 209 system has been a target of a project called MAPS – Molecules with ALMA at Planet-forming Scales – because the star is surrounded by a circumstellar disk with seven nested rings, suggesting the presence of multiple planets actively forming.