Grant: Discovery Grants Program - Individual

In the coming decade astronomy surveys will monitor the spectra from billions of stars in our Galaxy and beyond. From these spectra, astronomers will characterize the properties of stars, including their surface temperatures, gravities and atomic composition to probe the formation and evolution history of the Galaxy; the evolution and creation of elements in our Universe; and the structure and evolution of stars. But, these big surveys rely on our understanding stellar atmospheres and the physics anchoring those models. In the same way, we employ model stellar atmospheres to probe and characterize high-angular resolution exoplanetary transits and optical interferometric observations of stars that are sensitive to the intensity across the stellar disk. The combination of of big spectral surveys in the next decade, such as the Large Synoptic Survey Telescope (LSST), the Maunakea Spectroscopic Explorer (MSE), and SpecTel, with optical interferometric facilities and with planetary transit missions such as Transiting Exoplanet Survey Satellite (TESS)  will offer novel joint tests of the precise physics of stellar atmospheres. This approach is a novel methodology to bridge two tests of the physics of stellar atmospheres and lead about stars in unprecedented detail. The observations from both methods, spectroscopic and high-angular resolution, rely on models of stellar atmospheres to physically and precisely interpret them. There are currently no open source suites of modelling programs that can probe observations with the high precision. I will take advantage of the abundance of forthcoming measurements by using the state-of-the-art stellar atmospheres code SAtlas to create an open source environment for both fitting stellar spectra from surveys and fitting planet transit and optical interferometric measurements. This allows us to measure fundamental stellar parameters such as mass, radius and temperature along with composition; to more precisely characterize exoplanet atmospheres via transit measurements as function of wavelength; to measure the chemical history of stars across our Galaxy; and probe the cosmology at the local scale. These advancements will allow for dynamic and automated modelling of stellar atmospheres to construct grids across numerous parameters such as stellar surface temperature, mass and radius, and abundance of each element, along with testing additional physics in stellar atmospheres such as stellar convection, rotation, chemical stratification. The astronomy community in Canada has demonstrated leadership in constructing large spectral surveys such as LSST and MSE along with planetary transit observations through the MOST satellite missions and upcoming CASTOR and JWST missions. This work aims to create computational resources for gaining new insights into Galactic Archaeology and for characterizing stellar surfaces and exoplanetary atmospheres.