Series: Astronomy Colloquium
Date: Wednesday 28-Feb-2024
Time: 16:05-17:05 (4:05-5:05 pm)
Location: CSS 2400
Speaker: Dr. Adina Feinstein - University of Colorado
Title: A Tale of Planetary Adolescence and Evolution
Within the past decade, we have discovered only a dozen young (< 300 Myr) short-period exoplanets, compared to ~5,600 mature exoplanets. The radii of these young planets are larger than older planets on similar orbital periods. The leading hypothesis is that these young planets have inflated atmospheres because they are still contracting. Inflated atmospheres are more susceptible to photoevaporation -- atmospheric removal driven by high energy stellar irradiation. These effects are intensified in the earliest stages of planetary evolution, when young stars are more active and produce extreme levels of X-ray and Ultraviolet (UV) radiation on a variety of timescales. Even though it is challenging to study exoplanets around active stars, observational constraints of these targets provide crucial insights into our understanding of exoplanet formation and evolution. In this talk, I will present several benchmark studies of young stars and their planets spanning from the UV to the infrared (IR). I will present the results of several large statistical surveys of stellar flares with the Transiting Exoplanet Survey Satellite, and detailed characterization of stellar flares with the Hubble Space Telescope. I will present atmospheric follow-up characterization of young short-period exoplanets in the optical, near-IR, and IR. Finally, I will present models of flare-driven atmospheric escape, discuss the contributions of stellar flares in removing gas-dominated planetary atmospheres, and highlight future steps in understanding these challenging young systems.
In-person colloquia are usually preceded by espresso and ice cream at 1:45 pm outside room PSC 1150 and are followed by an informal reception at 5:15 pm in that room. Anyone interested in talking with the speaker, or being added to the colloquium announcement email list, should contact the colloquium organizer Dr. Leslie Sage. Lunch will normally be reserved for the speaker to talk to graduate students. Anyone asking a question during a talk is asked to raise their hand and be acknowledged before speaking. Contact Dr. Leslie Sage for details.
Colloquium Organizer:
Dr. Leslie Sage
Special accommodations for individuals with disabilities can be made by calling (301) 405-3001. It would be appreciated if we are notified at least one week in advance.
