Simulations of Magnetic Field Generation in Low-Mass Stars Across the Tachocline Divide

Weber Maria A, Exeter

Investigators

Abstract

Maria Weber is awarded an NSF Astronomy and Astrophysics Fellowship to conduct a program of research and education at the University of Chicago and at the Adler Planetarium. Stars like the Sun have a boundary region deep inside called the tachocline, which is thought to be necessary to generate a magnetic field. The smallest stars lack this boundary, but they can still have strong magnetic fields. Weber will develop computer models of magnetic activity in M dwarf stars, the smallest, most common stars in our galaxy. Results from her work will allow astronomers to understand how magnetism emerges in M dwarfs. Because many M dwarfs host planets, this work might also allow a better understanding of how stellar magnetic activity affects the conditions for life on such planets. Alongside this research, Weber will present colorful visualizations of her computer models, showing Adler Planetarium visitors how heat and magnetism are created inside a star and how they reach the stellar surface and beyond. Weber will also develop a science communication program for University of Chicago students. Weber will study the generation and emergence of magnetism in fully convective M dwarfs and in those with an imposed tachocline. She will produce the first set of simulations that address dynamo action and the rotation-activity correlation for M dwarfs across the partially-to-fully convective transition. The nature of the magnetism generated will inform separate simulations of flux emergence and allow astronomers to interpret observations of M dwarf magnetic activity. Her work will assess whether buoyant magnetic structures emerge self-consistently in these stars, as they are in rapidly rotating Sun-like stars. Comparing such structures with those studied through traditional flux emergence models will allow a better understanding of the flux pattern expected at the stellar surface. Weber will also seek to increase public science literacy by inspiring science communication through three-dimensional visualizations and by training students in the skills necessary to deliver impactful public presentations.