Aarhus Universitets segl

SAC seminar - Paolo Giacobbe, INAF-Astrophysical Observatory of Torino: The logbook of an exoplanet written in its atmosphere

Oplysninger om arrangementet


Fredag 29. oktober 2021,  kl. 14:15 - 15:15




The protagonist of this story is a gas giant planet, poetically named HD209458b.

With its period of three and a half days and a high equilibrium temperature, HD209458b is a particularly interesting object to study because it exhibits extreme physical conditions not found in our system. Moreover, to the great fortune of astronomers, HD209458b is a transiting planet. During transits, the star's light is filtered by the planet's atmosphere, which leaves the characteristic 'footprints' of the molecules it contains.

These fingerprints appear as a dense forest of thousands of absorption lines that can be resolved using high-resolution spectrographs. The spectra thus obtained enabled our team to identify six molecular species simultaneously for the first time: water, carbon monoxide, hydrogen cyanide, methane, ammonia and acetylene. Never before has the chemical composition of an extrasolar planet's atmosphere been studied in such detail.

The traces of these molecules are the alphabet of our planet's logbook, in which its history of formation and evolution is written.

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Meeting ID: 659 7497 2623

Passcode: SAC2021Sem