Dartmouth Events

Abstract: Low-mass M dwarfs are the most common type of star and key hosts for exoplanet detection and characterization. In the first half of my talk, I will discuss our volume-complete, multi-epoch, high-resolution spectroscopic survey of all low-mass M dwarfs within 15pc, including my work using this sample to constrain the occurrence rate of cold giant planets around these stars. In our solar system, the Earth's evolution was greatly shaped by the dynamical influence of Jupiter; while the occurrence rate of outer giant companions to inner terrestrial planets has been found to be quite high for Sunlike stars (roughly 40%), I find that the occurrence rate of giant planets at the snow line of low-mass M dwarfs is very low. These results indicate that architectures analogous to our solar system are rare around low-mass M dwarfs, with implications for the evolution and habitability of their terrestrial worlds. In the second half of the talk, I will discuss a series of projects that explore how these low-mass M dwarfs spin down, transitioning from the magnetically active, rapidly rotating state of their youth to the slowly rotating, relatively quiescent population we see in the field -- and with important implications for planetary atmosphere retention.

Hosted by Professor Elisabeth Newton