Blogarchiv
Astronomie - Exoplanet atmosphere hints it formed far from star

9.04.2021

Chemical fingerprint in exoplanet, Osiris, shows unexpectedly high carbon.

261158-850x

Artists impression of HD 209458b AKA Osiris. Credit: University of Warwick/Mark Garlick

A carbon-rich atmosphere suggests that the planet preferentially gathered up gas rich in carbon as it formed. This means it must have been born much further out in its solar system than its current position, a mere seven million kilometres from its star.

“There is no way that a planet would form with an atmosphere so rich in carbon if it is within the condensation line of water vapour,” Gandhi explains.

Models of planetary formation suggest that as a solar system forms, hotter planets close to a star gain a large proportion of oxygen in the atmosphere in water vapour. But further out, the water vapour condenses and becomes locked up in the planet’s core, leaving more carbon- and nitrogen-based molecules in the atmosphere.

This means Osiris must have formed far away from its star before migrating into its current position.

Co-author Matteo Brogi, also from the University of Warwick, says: “By scaling up these observations, we’ll be able to tell what classes of planet we have out there in terms of their formation location and early evolution.”

Quelle: COSMOS

1312 Views
Raumfahrt+Astronomie-Blog von CENAP 0