Characterizing astrospheres created by winds from low-mass binaries interacting with the ISM

Dartmouth College, Hanover NH

Investigators

Abstract

The investigator will numerically model the environment around stars that are gravitationally bound to each other rather than in isolation. This question is important because most stars are found in pairs or multiple star groups, not isolated like our Sun. The investigator notes that our nearest stellar neighbors, Alpha, Beta and Proxima Centauri are in a group of stars. This proposal will explore the conditions that any planets around these stars may experience due to the interaction of the outflows of material from the stars. The investigator will model the environmental conditions in multiple-star systems; the models can be tested by appropriate observations of the Centauri group. The investigator will strongly connect undergraduate students with this research project. The investigator will also mentor first year undergraduate students, who will work on this project through the auspices of the "Women in Science Project" at Dartmouth College. This program encourages more women to pursue a career in STEM through early exposure to hands-on research experience, role modeling, and mentoring. The investigator will study the region of interaction of stellar winds with the surrounding interstellar medium; a region the investigator calls the 'astrosphere'. In particular, the research focuses on astrospheres of binary stars, which have the additional feature of wind-wind interactions between the two stellar winds. Both the wind-wind and the wind-ISM interactions produce shocks and associated radiation/particle interactions. The investigator?s central theme is the ramifications for any planets that might be associated with the system. Effects can include the planet's thermal and chemical atmosphere structure, and over the long-term erosion of the planet's atmosphere, as is thought to have happened with Mars. The interaction of magnetized solar winds with the planet's magnetic field also affects cosmic ray transport and exposure Such effects are important for shaping the expected properties of a planet's atmosphere, and studies of those atmospheres will become important during the coming years when current lists of recently discovered exoplanets will be observed in more detail.