Linn Boldt-Christmas (Uppsala University): Obstacles in observing exoplanet atmospheres (Pre-defence seminar)

Friday 23 May 2025, 14:00 → 15:00 Europe/Stockholm

90101Å

Title: Obstacles in observing exoplanet atmospheres
Speaker: Linn Boldt-Christmas
Affiliation: Uppsala University
Time: Friday 23 May 2025, 1400 to 1500
Location: 90101Å

Abstract:

As of 2025, we have confirmed the existence of nearly 6,000 planets in orbit around stars other than our Sun.  By studying this growing sample of exoplanets, we can begin to contextualise our own Solar System regarding what types of planets might be common or uncommon in our galaxy.  Beyond basic measurements of an exoplanet’s mass and radius, taking spectroscopic observations during an exoplanetary transit allows us to study the chemical composition of its upper atmosphere.  This technique, known as transmission spectroscopy, has been successfully practiced for well over two decades by now and has yielded a remarkable wealth of new knowledge about exoplanet atmospheres, chemistry, and formation.  However, the advent of cutting-edge instrumentation and observatories in the recent past and future is now encouraging the field to move beyond the simpler case studies of hotter gas giants and more towards cooler and smaller planets, which means that some of our current methodology and analysis techniques are being pushed into new and unexplored regimes.  Where do the limits of our tools and techniques lie in this new era?  What are our major challenges, and why are they particularly problematic?  And how close are we to being able to detect and characterise the atmospheres of Earth-like planets in our search for biosignatures?