Habitability of Earth-like exoplanets around low-mass stars

Giorgi, Erika (2021) Habitability of Earth-like exoplanets around low-mass stars. Bachelor's Thesis, Astronomy.

Preview	Text bAST_2021_GiorgiE.pdf Download (1MB) | Preview
	Text toestemming.pdf Restricted to Registered users only Download (127kB)

Abstract

Low-mass stars, in particular M-dwarfs, are the most abundant type of star in the solar neighbourhood. If they are host to rocky, terrestrial exoplanets, these systems could be optimal candidates for finding extraterrestrial life due to the long evolutionary timescales of their central stars. On Earth, the carbon cycle has played a large role in stabilizing the climate over the past few billion years via the CO2 pressure linked to the greenhouse effect. In this thesis, we study the long-term evolution (up to 20 Gyr) of the planetary surface temperature and the atmospheric CO2 pressure on an Earth-like exoplanet orbiting stars of M-K spectral type. This is achieved through the planetary evolution and carbon cycle model of Oosterloo (2020). These two quantities are necessary to determine the potential habitability, based on the presence of surface liquid water and adequate pCO2 levels, regulated by the negative feedback mechanism of the carbon cycle. We find that with the slight increase in stellar luminosity for very low mass stars ( ~ 0.1 M☉), a planet must be very close, within 0.023 - 0.029 AU, in order to support habitable surface temperatures without taking into account the effects of stellar flares and tidal locking. A 0.5 M☉ mass star is also modeled, with a more significant increase in luminosity, warming the surface temperature of its exoplanet and thus decreasing the atmospheric CO2 pressure over time, with an average distance between 0.175 - 0.223 AU.

Item Type:	Thesis (Bachelor's Thesis)
Supervisor name:	Kamp, I.E.E. and Oosterloo, M.
Degree programme:	Astronomy
Thesis type:	Bachelor's Thesis
Language:	English
Date Deposited:	09 Jul 2021 12:43
Last Modified:	09 Jul 2021 12:43
URI:	https://fse.studenttheses.ub.rug.nl/id/eprint/25093

Actions (login required)

View Item