New Delhi: The James Webb Space Telescope has peered into a circumstellar disk for the first time. The disk is surrounding a large exoplanet designated as CT Cha b, with the host star around 625 lightyears from the Earth. CT Cha b is at a distance of about 496 astronomical units (AU) from its host star, with a single AU being the distance between the Earth and the Sun. The star is only two million years old, and is still growing from the infalling disk of gas and dust. The circumstellar disk is rich in water but contains hardly any carbon, while the circumplanetary disk is rich in carbon.
The system reveals the complex chemistry at work in a system that is less than two million years old. Webb has been able to spot a number of carbon-rich molecules in the circumplanetary disk, including benzene, hydrogen cyanide, acetylene and benzene. Scientists believe that the four largest moons of Jupiter, Europa, Ganymede, Callisto and Io, also known as the Galilean Moons were formed from a circumplanetary disk in the infancy of the Solar System, because of their co-planar orbits around Jupiter. The observations help scientists better understand the formation of moons and planets in the galaxy.
Habitable Exomoons
Astronomers have discovered over 6,000 exoplanets, but not a single confirmed exomoon, although a few candidates are known. Scientists suspect that the number of exomoons far outnumber the number of exoplanets in the Milky Way. As such, exomoons may offer more habitable opportunities for life as we know it than planets. Studying exomoons and circumplanetary disks will help astronomers better understand the prospects for life across the galaxy. Over the course of the next year, the James Webb Space Telescope will conduct a comprehensive survey of exoplanetary disks.