A HIGH ANGULAR RESOLUTION SURVEY OF MASSIVE STARS IN CYGNUS OB2: RESULTS FROM THE HUBBLE SPACE TELESCOPE FINE GUIDANCE SENSORS
S. Caballero-Nieves, E. Nelan, D. Gies, D. Wallace, K. DeGioia-Eastwood, A. Herrero, W. Jao, B. Mason, P. Massey, A. Moffat, N. Walborn