ChrisTheissen

Research Interests

I am an astronomer (astrophysicist) studying planetary evolution around low-mass stars (M dwarfs).

For more info refer to my papers (ADS/arXiv) for more technical details.

Kepler has found hundreds (potentially thousands) of planets not in our Solar System, or exoplanets. Although the majority of planets have been found around "Solar"-type stars (stars a little bigger and a little smaller than our Sun), there have also been many planets found around M dwarfs, the most populous type of star in the Galaxy. In fact, observational evidence suggests that these low-mass stars may form many small, terrestrial planets (planets like Earth and Mars). Many future efforts wil be targeted at finding planets around M dwarfs.

With so many "habitable" worlds within our observational grasp, the question remains, what makes a world habitable? To zeroth-order, astronomers typically say a planet must be able to sustain liquid water. But what about other aspects of Earth that we may take for granted (seasons, the Moon, other planets, etc.)? There are many aspects, not only of our planet, but of our Solar System, which appear to be unique compared to the planetary systems we have found. In fact, it is only in recent years that we have been able to model most of the aspects of our own Solar System, requiring migration of the giant planets to reproduce all of our Solar System's unique idiosyncracies (see The Grand Tack Scenario and the Nice Model).

M dwarf SED with IR excess

I'm intersted in understanding how important planetary migration is for habitability, and how frequently does it occur around small stars with many small planets. My current research is focused on looking for signs of planetary collisions around small stars, and investigating the frequency of such occurrences around low-mass stars.

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