Free Astronomy Magazine November-December 2022

26 NOVEMBER-DECEMBER 2022 ASTRO PUBLISHING jects, and control the growth of young, giant planets. Studying these disks in their earliest stages may help shed light on the forma- tion of our own Solar System, in- cluding that of Jupiter’s Galilean moons, which scientists believe formed in a circumplanetary disk of Jupiter around 4.5 billion years ago. While studying AS 209 — a young star located roughly 395 light-years from Earth in the constellation Ophiuchus — scientists observed a blob of emitted light in the middle of an otherwise empty gap in the gas surrounding the star. That led to the detection of the circumplane- tary disk surrounding a potential Jupiter-mass planet. Scientists are watching the system closely, both because of the planet’s distance from its star and the star’s age. The exoplanet is located more than 200 astronomical units, or 18.59 billion miles, away from the host star, chal- lenging currently accepted theories of planet formation. And if the host star’s estimated age of just 1.6 mil- by ALMA Observatory Nicolás Lira First-ever detection of gas in a circumplanetary disk S cientists using the Atacama Large Millimeter/submillimeter Array (ALMA) to study planet formation have made the first-ever detection of gas in a circumplane- tary disk. What’s more, the detec- tion also suggests the presence of a very young exoplanet. The results of the research have been published in The Astrophysical Journal Letters . Circumplanetary disks are an amass- ing of gas, dust, and debris around young planets. These disks give rise to moons and other small, rocky ob-