As the most commonly observed objects, stars remain at the forefront of astrophysical research. Technical advances in detectors, computer processing power, networks and data storage have enabled new sky surveys. Many of these search for transient events at optical wavelengths, such as the Palomar Transient Factory and Pan-STARRS1 that probe ever-larger areas of the sky and ever-fainter sources, opening up the vast discovery space of "time domain astronomy". The recent Kepler and COROT space missions achieved nearly continuous monitoring of more than 100,000 stars. The stellar discoveries from these surveys include revelations about stellar evolution, rare stars, unusual explosion outcomes, and remarkably complex binary star systems. The immediate future holds tremendous promise, as both the space-based survey Gaia and the ground based Large Synoptic Survey Telescope come to fruition. This tsunami of data has created a new demand for a reliable and publicly available research and education tool in computational stellar astrophysics that will reap the full scientific benefits of these discoveries while also creating a collaborative environment where theory, computation and interpretation can come together to address critical scientific issues. This demand by the stellar community led to our release of the Modules for Experiments in Stellar Astrophysics (MESA) software project in 2011. MESA has driven, and will continue to drive with support from this award, innovation in the stellar community as well as the exoplanet, galactic, and cosmological communities. Educators have widely deployed MESA in their undergraduate and graduate stellar evolution courses because MESA is a community platform with an active support network for leading-edge scientific investigations. Stellar astrophysics research, and all the communities that rely on stellar astrophysics, will be significantly enhanced by sustaining innovative development of MESA.
This award supports the Modules for Experiments in Stellar Astrophysics (MESA) software project and user community. MESA solves the 1D fully coupled structure and composition equations governing stellar evolution. It is based on an implicit finite difference scheme with adaptive mesh refinement and sophisticated timestep controls; state-of-the-art modules provide equation of state, opacity, nuclear reaction rates, element diffusion, boundary conditions, and changes to the mass of the star. MESA is an open source library that employs contemporary numerical approaches, supports shared memory parallelism based on OpenMP, and is written with present and future multi-core and multi-thread architectures in mind. MESA combines the robust, efficient, thread-safe numerical and physics modules for simulations of a wide range of stellar evolution scenarios ranging from very-low mass to massive stars. Innovations in MESA and its domain of applicability continues to grow, just recently extended to include giant planets, oscillations, and rotation. This project will sustain MESA as a key piece of software infrastructure for stellar astrophysics while building new scientific and educational networks.
