Infrared speckle observations of the nucleus of M 31 : new light on the suspected black hole. Spillar, E. J. ; Canterna, R. ; Benson, J. A. ; Dyck, H. M. ; Carels, K. H. Abstract Publication: Bulletin of the American Astronomical Society Pub Date: January 1989 Bibcode: 1989BAAS...21..710S