A black hole with mass 3.8 to 6.9 times that of the Sun is found to be orbiting the nearby Be-type star MWC 656; the black hole is encircled by an accretion disk and X-ray quiescent, implying that Be binaries with black-hole companions are difficult to detect in conventional X-ray surveys.
- J. Casares
- I. Negueruela
- S. Simón-Díaz