Monday, 16 March 2026
The discovery of extrasolar planets enables us to tackle millennia old questions about whether the Earth and our Solar System are unique, and how they formed, and whether Life exists beyond the Earth. The 6000 exoplanets now known reveal many of the underlying mechanisms of how planets form and evolve, and the complex interplay between stars and the planets over time in sculpting the atmospheres of planets and the architecture of planetary systems.
In this talk I will discuss the techniques we use to discover exoplanets, the challenges of detecting terrestrial planets like the Earth, capable of hosting liquid water on their surface, and how the coolest most numerous stars in the Galaxy are potentially attractive targets. New precision spectroscopic and photometric instruments are now beginning to discover and characterize rocky planets around the coolest stars, and discovering ways to mitigate the noise from the stars themselves, that currently limits our ability to discover planets like our own around the nearest Sun-like stars.
The talk will also discuss how these discoveries pave the way for NASA's next flagship mission - the Habitable World Observatory, which will be capable of observing these new worlds in reflected light, and analyzing this light to search for biosignatures in their atmosphere. The ability to answer the age-old question of whether Life exists outside the solar system is now within our reach!
In this lessons I will focus on the specificities of Extremely Precise Radial-Velocity (EPRV) Spectrographs and show on the basis of examples (HARPS, ESPRESSO and NIRPS) what makes the difference.
The atmosphere of brown dwarfs is very much similar to that of hot giant planets. Therefore, understanding the atmosphere of brown dwarfs provides important insight onto the atmosphere of gas giant extra-solar planets. Depending on their spectra, brown dwarfs are divided into three classes : L, T and Y dwarfs. The indirect evidence for the presence of dust cloud in the atmosphere of L dwarfs comes from the diagnosis of its optical and infra-red spectra. The direct evidence of dust comes from the detection of linear polarization in the optical bands. In the first part of the lecture, I shall discuss the physical and chemical properties of the atmosphere of brown dwarfs derived from the detail theoretical analysis of the observed spectra as well as the observed photo-polarimetric data. The second part of the lecture will describe analysis of atmosphere of exoplanets- both gas giant and telluric by using transmission spectra. It'll be demonstrated that polarisation may serve as a potential tool to probe the atmosphere of exoplanets.
Tuesday, 17 March 2026
In this pedagogical lecture I will review the main discovery techniques for exoplanets, and their relative strengths and weaknesses. The goal will be to understand what parameter space each discovery technique shines in, and how combinations of some of these techniques can further increase our understanding of exoplanet properties.
I will described how high-fidelity, radial-velocity spectrographs work and how they are employed for the search and characterisation of exoplanets
Wednesday, 18 March 2026
All magnetized solar system planets are strong radio emitters. Similar radio emissions have been found in the lowest mass stars and brown dwarfs and searches for radio emission from exoplanets is underway. These emissions are thought to be powered by various mechanisms drawing energy from the rotation of the emitting object, magnetic reconnection and/or magnetized wind impinging on the object. In this talk I will review the fundamentals of the relevant emission mechanisms, the plasma conditions that lead to such emissions, phenomenology of the observed emission and open questions in the field.
The observation of the first hot Jupiters around 3 decades ago has fuel the field of planet formation as the origin of these planets is still unknown at the present day. As such, planet formation models face the challenge to bridge two distinct states within the timeframe of the observations of planetary systems: the protoplanetary disc stage during which the planets form and the final (exo)-planetary system. This implies that models of planet formation need to include the structure and evolution of the protoplanetary discs, the accretion and migration processes of the growing planets as well as their composition. Consequently many different initial parameters of the disc (e.g. disc mass, disc radius, viscosity) and the planet (e.g. starting position and time) can be chosen. However, the number of observational constraints (e.g. planetary mass, final orbital distance) is limited, giving rise to a degeneracy within the models. A promising avenue to extend these observational constraints are measurements of atmospheric abundances, where observations via the JWST provide unprecedented data. In this talk, I will introduce the ingredients of planet formation models and how we can link these models to constraints from exoplanetary atmospheres to reveal the formation location of (hot) giant planets.
Thursday, 19 March 2026
All magnetized solar system planets are strong radio emitters. Similar radio emissions have been found in the lowest mass stars and brown dwarfs and searches for radio emission from exoplanets is underway. These emissions are thought to be powered by various mechanisms drawing energy from the rotation of the emitting object, magnetic reconnection and/or magnetized wind impinging on the object. In this talk I will review the fundamentals of the relevant emission mechanisms, the plasma conditions that lead to such emissions, phenomenology of the observed emission and open questions in the field.
A pedagogical overview and tutorial on the current research in exoplanetary star planet magnetic interactions