1. Physics Department, University of Alabama in Huntsville, Huntsville, AL 35899, USA
2. The Observatories of the Carnegie Institution for Science, Pasadena, CA 91101, USA
3. Department of Physics, Yale University, New Haven, CT 06520, USA
4. Department of Astronomy, Yale University, New Haven, CT 06520, USA
5. Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT 06520, USA