Branco Weiss Fellow Since
2021
Research Category
Astrophysics
Research Location
Max-Planck Institute for Astrophysics (MPA), Garching, Germany
Background
Detailed insights on stellar interior structures and physics are currently being made possible through the study of stellar oscillations, which are stochastically excited and intrinsically damped by turbulence in the outermost layers of stellar convective envelopes (i.e., Asteroseismology). These oscillations are of similar nature to those observed in the Sun, thus known as solar-like oscillations. Solar-like oscillations carry information allowing fundamental stellar parameters (e.g. radius, mass, and age) to be precisely determined, while also paving the way for the interior stellar structure to be constrained to unprecedented levels; given that individual oscillation mode frequencies are measured.
Furthermore, asteroseismology has proven to be an effective technique in determining the exoplanet-host star parameters precisely. This in turn has enhanced the characterisation of extra solar planetary systems thus fostering the synergies between planetary science and asteroseismology. The available wealth of seismic information made possible from space missions such as the French-led CoRoT satellite, NASA’s Kepler space telescope, and more recently, NASA’s TESS, when coupled with precise classical observables (i.e., effective temperature and metallicity), Gaia-based luminosities, and interferometric radius measurements, set a platform for constraining stellar interiors and testing stellar model physics through asteroseismic techniques, i.e., by matching stellar observables to evolution models.
Details of Research
The goal of Dr. Benard Nsamba’s project is twofold. First, the scientific research goal is to use photometric data from Kepler and TESS main-sequence stars with solar-like oscillations to explore the impact of stellar interior physics (i.e., convective core overshoot, rotation, metallicity mixtures, atomic diffusion including gravitational settling) on the nature and sizes of stellar cores. An additional important aspect will involve a comprehensive examination of the extent of overshooting and its relationship with stellar parameters. To this end, the scientific research goal of this project will involve combining skills in photometry/asteroseismic data analysis, spectroscopic analysis, and stellar modelling.
Secondly, the society goal of this project involves an outreach component dedicated to using astronomy as a tool to stimulate the interest of high school students in STEM (science, technology, engineering, and mathematics) subjects, in addition to encouraging and motivating them to consider science related careers. Astronomy is considered to be a stimulating, appealing subject, and an excellent tool for conveying scientific knowledge to young students, with tremendous success recorded in various countries across Africa (e.g. SouthAfrica, Ethiopia, Ghana). The goals of this project are aligned with the United Nations Sustainable Goals of attaining quality education, enhancing gender equality, and promoting world peace through building sustainable science research collaborations across international boarders.