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Thursday, 13 April 2023

Video-Recording for any system with MP4-support

- Video.mp4 (ca. 368 Mb)

15:15 – 16:15

"Observability of short-period rocky exoplanets"

Yamila Miguel

(Leiden Observatory)

Abstract: Short-period rocky exoplanets can reach surface temperatures

high enough to melt their silicate crust. Theory predicts that the

resulting lava oceans outgas their volatile components, attaining

equilibrium with the overlying vapour. This could create atmospheres

made out of silicates that mix with other volatiles that might have been

present in such atmospheres. With the recently successful deployment of

the James Webb Space Telescope (JWST), it is now possible to characterise

these worlds.

In this talk, we assess JWST observability of key spectral features

by self-consistently modelling these atmospheres. We use outgassed

equilibrium chemistry and radiative transfer methods to compute

temperature-pressure profiles, atmospheric chemical compositions

and emission spectra. Our results indicate that SiO and SiO2 infrared

features are the best in pure lava worlds. However, even a small amount

of volatiles, especially H2O and H–, may hinder its observability. We

also find that the carbon to oxygen (C/O) ratio plays a large role in

determining the abundance of SiO. Detecting SiO on a strongly irradiated

planet could indicate an atmosphere with high metallicity and a low

C/O ratio, which may be a result of efficient interaction between the

atmosphere and the underlying melt.

Biography: Yamila Miguel got her PhD in 2011 in Astronomy from the

Universidad Nacional de La Plata in Argentina. She then had a postdoctoral

fellowship at the Max Planck Institute for Astronomy in Heidelberg

and in 2015 the Henri Poincare postdoctoral fellowship at the Côte

d’Azur Observatory. After another fellowship by the National Centre

for Space Studies, also in Nice, she became an Assistant Professor at

Leiden Observatory.

Yamila Miguel is well known for her public outreach activities through

lectures, newspaper articles, and radio appearences. She is a member of

the Young Academy Leiden.