The rate at which low mass stars flare is a subject of significant current interest for understanding magnetic dynamo evolution, the effect of flares on the evolution of nearby planets, and the transient variability signature of flares in present and future large time-domain sky surveys. Here, a major observational program will be undertaken to obtain new data on flare light curves, frequencies and energies for classes of low mass stars that have been previously ignored (relatively inactive stars, and very late type stars). A set of numerical simulations to model M dwarf flares on a Galactic scale will also be carried out.
With these new data, Dr. Hawley and collaborators will determine the changes in flare activity that occur as stars become fully convective, providing insight and empirical constraints on new turbulent dynamo models for magnetic field production. The flare data will also be incorporated into models of planetary atmosphere evolution under the influence of flaring from the parent star. The numerical simulations will transform the study of individual flares on a few nearby stars into definitive predictions of the global implications of M dwarf flares on a Galactic scale.
The observational component of the project will be fully integrated into the University of Washington's Pre-Major in Astronomy Program (Pre-MAP) and the advanced undergraduate Capstone observing sequence. Pre-MAP is focused on increasing diversity by immediately involving freshmen from under-represented populations in research projects beginning in their first quarter of study. The Capstone sequence trains advanced undergraduate astronomy majors in observational techniques, data reduction and analysis using a 1-meter class telescope at the nearby Manastash Ridge Observatory. Faculty and graduate students will work with both freshmen and advanced undergraduates, and the undergraduates will additionally work with each other, building a mentor-ladder that will benefit the individual students. This project will also support two graduate students whose thesis material will come from this project.
The major research activities carried out under this grant included mining the SDSS data for flare rates, the collection of nearly 1000 hours of new flare monitoring observations from the ground, extensive photometric monitoring of flare stars from the MOST and Kepler satellites that complements and expands our ground-based observations, and the development of a quantitative flare-finding algorithm that was used to identify flares in all of the data. The final sample includes more than 200 flares in the ground-based data, and more than 1000 flares in the satellite data. In addition, we constructed a model for flare rates in the Galaxy that incorporates the most recent determinations of the mass and luminosity functions for M dwarfs, as well as statistical assignment of magnetic activity status, and uses the new flare rates determined from our monitoring observations to assign a flare probability for every low mass (Galactic) star in the field of view during a given specified survey observation, for example from LSST. Finally, we have compiled and analyzed a large survey of simultaneous photometric and spectroscopic flare observations on nearby active stars, to investigate the physical processes in stellar flares and their potential impact on planets orbiting similar stars. Educational and broader impact activities included the support of two PhD theses, several other graduate and undergraduate research projects, and three years of participation in the University of Washington Pre-MAP diversity initiative to provide a research immersion experience for entering freshmen from under-represented backgrounds.
