Abstract
The Maunakea Spectroscopic Explorer (MSE) is a planned 11.25-m aperture
facility with a 1.5 square degree field of view that will be fully dedicated to
multi-object spectroscopy. A rebirth of the 3.6m Canada-France-Hawaii Telescope
on Maunakea, MSE will use 4332 fibers operating at three different resolving
powers (R ~ 2500, 6000, 40000) across a wavelength range of 0.36-1.8mum, with
dynamical fiber positioning that allows fibers to match the exposure times of
individual objects. MSE will enable spectroscopic surveys with unprecedented
scale and sensitivity by collecting millions of spectra per year down to
limiting magnitudes of g ~ 20-24 mag, with a nominal velocity precision of ~100
m/s in high-resolution mode. This white paper describes science cases for
stellar astrophysics and exoplanet science using MSE, including the discovery
and atmospheric characterization of exoplanets and substellar objects, stellar
physics with star clusters, asteroseismology of solar-like oscillators and
opacity-driven pulsators, studies of stellar rotation, activity, and
multiplicity, as well as the chemical characterization of AGB and extremely
metal-poor stars.