Arne Grenzebach, ZARM, Universität Bremen, Germany
Black holes are perhaps the most intriguing objects in Astrophysics. Due to the strong gravity and the resulting deflection of light, the black hole will cast a shadow. I will introduce an analytic geometrical way to construct the black hole’s shadow whose shape varies in different space-times. The corresponding formulas describe the boundary of the shadow for the general Plebański–Demiański class of stationary, axially symmetric type D solutions of the Einstein-Maxwell equations seen by an observer at arbitrary position. An observed image of the shadow would be a strong evidence for the existence of black holes.