Series: Astronomy Colloquium
Date: Wednesday 05-Mar-2025
Time: 16:05-17:00 (4:05-5:00 pm)
Location: ATL 2400
Speaker: Dr. Luke Bouma (Carnegie Observatories)
Title: Hot and Cold: The Circumstellar Environments of Young Low-Mass Stars
Over the past decade, photometric surveys conducted from space have opened tremendous opportunities for deepening our understanding of how exoplanets and stars evolve. Red dwarf stars in particular are enabling the study of close-in rocky exoplanets. However, the circumstellar particle and radiation environments of these stars differ from those of Sun-like stars, and these environments are observationally challenging to study. In this context, an important surprise has been the discovery that a small fraction of young red dwarfs show optical light curves with complex periodic variability, suggesting the presence of transiting clumps of opaque material corotating with the star for months to years. The composition, and even the existence, of this material have been debated. I'll give an overview of this new area of study, describe competing interpretations of the data, and present new ground-based observations that argue for this phenomenon being associated with extended clumps of circumstellar plasma. In the coming decade, a firehose of data from Roman, Rubin, JWST, Gaia, and TESS will continue to drive data-driven discovery in exoplanet and stellar astrophysics; these specific stars offer one case study of what can be learned from the surprises.
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. Richard Mushotzky. 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. Richard Mushotzky for details.
Colloquium Organizer:
Dr. Richard Mushotzky
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.
