Publication in: Spring 2024 Issue

Title:
Sustaining liquid water on Earth-like planets: the importance of star-planet interactions
Author(s):
Abby Grulick
Author Email:
agrulick@unca.edu
Department:
PHYSICS & ASTRONOMY
Faculty Mentor(s):
Christene Lynch
Abstract / Summary:
Many factors relating to the star, planet, or both can contribute to its ability to maintain surface liquid water. Important stellar characteristics include spectral type and luminosity while key planetary features include distance away from the star and mass. Given the right combinations, a planet could potentially support prolonged surface water. In order to find these optimal conditions, I created a set of hypothetical star-planet systems with varying stellar masses, planetary masses, and semi-major axes. For this study, each system was given four Terrestrial Oceans, TO, of water to start. To deduce habitability, I observed planets only when they were located within their star’s habitable zone at one billion years. I deemed a planet habitable if it had at least one TO at this period in time. Given these parameters, I found smaller semi-major axes require low-mass stars for the planets in that system to be considered habitable. This proportional relationship also applies to larger semi-major axes. However, there are some exceptions when it comes to middle-range planet masses since they cannot maintain enough water to be considered habitable. After determining the most habitable hypothetical systems, I compared them to NASA’s database of exoplanets to see how likely it is for these systems to exist. Based on what is currently known, there are only a few systems that match the ones modeled in this study.
Publication Date:
May-14-2024
Documents: