The Shortest Known Period Star Orbiting our Galaxy's Supermassive Black   Hole
  Stars with short orbital periods at the center of our galaxy offer a powerful and unique probe of a supermassive black hole. Over the past 17 years, the W. M. Keck Observatory has been used to image the Galactic center at the highest angular resolution possible today. By adding to this data set and advancing methodologies, we have detected S0-102, a star orbiting our galaxy's supermassive black hole with a period of just 11.5 years. S0-102 doubles the number of stars with full phase coverage and periods less than 20 years. It thereby provides the opportunity with future measurements to resolve degeneracies in the parameters describing the central gravitational potential and to test Einstein's theory of General Relativity in an unexplored regime. 
L. Meyer, A. M. Ghez, R. Schoedel, S. Yelda, A. Boehle, J. R. Lu, T.   Do, M. R. Morris, E. E. Becklin, K. Matthews
astro-ph.GA