Description:

Abstract: Results from NASA’s Kepler Mission indicate that low-mass stars, specifically M dwarf stars, are swarming with terrestrial exoplanets.  The results have inspired several surveys for exoplanets orbiting stars at the bottom of the main sequence and have led to a renewed interest in the fundamental properties of low-mass stars.  I will present recent results from the Low-mass Star Group at Boston University in these areas.  We are particularly interested in measuring M dwarf elemental abundances; however, this is confounded by the role of the stellar carbon-to-oxygen ratio and Zeeman enhancement of individual absorption lines.  I also will present recent results on the M dwarf mass-radius relationship.  Lastly, I will discuss a new search for transiting planets and satellites around L and T dwarfs called the Perkins Infrared Exosatellite Survey, or PINES.  L and T dwarfs can be either stars, brown dwarfs or planetary-mass objects, all of which appear to have proto-planetary disks early in their lives.  Their disks, combined with the increase in exoplanet occurrence with decreasing host mass seen in M dwarfs, suggest that L and T dwarfs should also be swarming with planets and moons, which motivates the PINES project.  I will describe the survey and present our latest results.

Speaker: Prof. Philip Muirhead, Boston University

Website: https://www.bu.edu/astronomy/profile/phil-muirhead/

Host: TBD

This will be an in-person event.