Antoine Darveau-Bernier, an iREx scholar at Université de Montréal, submitted his thesis within the fall of 2022. Right here he summarises the analysis tasks he performed as a part of his Ph.D.

Learning the ambiance of the most well liked large exoplanets, from Earth and from area

My PhD geared toward creating knowledge evaluation methods to check the ambiance of exoplanets. Afterwards, I used to be capable of apply one in all these strategies to look at the second hottest exoplanet identified so far, WASP-33 b. To take action, we used the SPIRou instrument positioned on the Canada-France-Hawaii Telescope. This planet, that has a dimension and mass much like Jupiter, is positioned so near its star that it takes solely 29 hours to orbit round it! This proximity has the consequence of forcing WASP-33 b to all the time present the identical facet to its star, a bit just like the Moon with the Earth. This “day facet” is consistently irradiated by its star and might thus attain extraordinarily excessive temperatures (as much as 3400°C!), approaching these of the coldest stars. Our evaluation has allowed us to measure for the primary time the abundance of carbon monoxide current within the ambiance of this planet, along with measuring the temperature current at totally different altitudes.

Inventive illustration of the James Webb Area Telescope, on which Antoine labored throughout his PhD. Credit score. NASA GSFC/CIL/Adriana Manrique Gutierrez.

To attain this, we needed to apply a novel methodology to tell apart the sunshine emitted by the ambiance of WASP-33 b, and that’s buried within the sign of its star. By decomposing this mild in response to its totally different colours (wavelengths), it’s potential to establish the signature of a number of molecules current within the ambiance, like carbon monoxide or water. Certainly, every molecule absorbs mild at particular wavelengths, which provides a definite signature resembling a bar code. This signature is influenced by the variations of pace because of the (very quick!) motion of the planet round its star. That is known as the “Doppler impact”. The star additionally strikes, however rather more slowly; it’s subsequently potential to make use of this impact to tell apart the sign of the planet from that of the star.

I additionally had the possibility to work on the event of an algorithm known as ATOCA devoted to the evaluation of knowledge from the NIRISS instrument, the Canadian contribution to the well-known James Webb Area Telescope. ATOCA will make it potential to get essentially the most out of the observations taken by this instrument, with the intention to reveal the mysteries of the ambiance of assorted exoplanets.

My thesis is subsequently about perfecting knowledge evaluation methods utilized to the ambiance of exoplanets, each for observations taken on Earth (with SPIRou) and from area (with JWST).

Extra info

Antoine accomplished his Ph.D. at Université de Montréal between 2016 and 2022, beneath the supervision of Prof. René Doyon and David Lafrenière. His thesis will probably be obtainable quickly.



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