Monday, October 1, 2018 at 4:00pm to 5:00pm
Rockefeller Hall, Schwartz Auditorium
General Physics Colloquium, Professor Keivan G. Stassun, Stevenson Professor of Physics and Astronomy, Vanderbilt University.
Refreshments from 3:30-3:50 pm.
Title: An Era of Precision Astrophysics for Exoplanets, Stars, and the Milky Way
Host: Dong Lai
Abstract: While observing stars teaches us about the physical properties of the stars themselves, that knowledge also is the key to measuring the properties of nearly all exoplanets, and also the history of our Galaxy. Combining data from current and upcoming all-sky surveys, including the European Gaia mission, NASA's Transiting Exoplanet Survey Satellite (TESS) mission, and the fifth Sloan Digital Sky Survey (SDSS-V), will enable accurate, empirical measurements of fundamental properties for millions of stars throughout the Milky Way—including an increase by four orders of magnitude in the number of stars with reliable parallaxes, two orders of magnitude in the number with ultraprecise light curves, and two orders of magnitude in the number with detailed chemical abundances. We demonstrate that stellar masses, radii, temperatures, distances, space motions, and detailed chemical abundances can now be measured with precisions of order 1%. We discuss the transformational advances that such precise stellar measurements promise for exoplanet science, including studies of planetary system architectures, forensic analyses of planet evolution pathways, testing planet formation theories, and even efforts to infer the mineralogy of planets. We also discuss the similarly transformational advances at hand for "Galactic archaeology", including studies of stellar micro-populations, testing theories of star formation and of galaxy assembly, and even efforts to trace the chemical "family tree" of the Galaxy through stellar phylogenics. Finally, we discuss the revolution in stellar astrophysics represented by ultraprecise light curves of stars, specifically as probes of stellar interiors and therefore as stress-tests of stellar theory.