High Angular Resolution Investigations of Binary Stars and their Disks

Georgia State University Research Foundation, Inc., Atlanta GA

Investigators

Abstract

The Center for High Angular Resolution Astronomy (CHARA) optical interferometer array on Mt. Wilson is the nation's premiere facility for high angular resolution astronomy. This proposal describes a program to investigate binary stars and the disks of gas and dust that form around them. Images of these debris disks can now be obtained for the closest and largest examples using CHARA. The first part of the program is aimed at determining the orientation of the binary orbits with respect to their surrounding disks. The second part is a survey of binary systems that are undergoing an intense stage of mass exchange between the stars. The third part will be a program to image a set of stellar disks and search for indications of spiral arms. Finally, they will use CHARA to search for faint companions in other systems. The program will directly support the continued training of a research scientist, a postdoctoral associate, and several Ph.D. students at Georgia State University, which operates the CHARA array. The work will be highlighted in the undergraduate courses taught at GSU, which has a very diverse student population with a large minority component, and advanced undergraduates will participate in work at CHARA. The team will also support public outreach efforts at GSU and at Mt. Wilson, including the renewal of exhibits at the CHARA Visitors Gallery. The project will provide us with fundamental data on binary star systems with disks in their youth and after their transformation through mass transfer and loss. The study of binaries in debris disks will show how disks act to form binary stars and, once formed, how the binary systems implant structures in the disks that will influence where and how planets are formed. Detection of circumbinary disks around strongly interacting binaries will show us how much mass and angular momentum are lost from the system during the peak of mass transfer. Observations of structures in the disks of Be stars will provide the means to test theories of tidal processes and disk perturbation modes that are important in our understanding of star and planet formation, accretion processes in X-ray binaries, and accretion onto supermassive black holes. Detection of the mass donor remnants orbiting rapidly rotating stars will reveal the products of binary star evolution and shed light on the processes that lead to other products of mass transfer (massive X-ray binaries, hydrogen deficient supernovae, long duration gamma-ray bursts, neutron stars, black holes, and gravitational waves from mergers). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.