How to spot a black hole on the Sky

Here is a video from NewScientist featuring simulations by Loeb and his collaborators (we have discussed Loeb’s results several times on NEQNET). The idea is that BH acts as a strong gravitational lense, so if we have a close system “star-BH”, we will see a very specific pattern of light when the companion star crosses the “disk” of BH. Of course, in order for us to spot this pattern, it is better if the line of our sight lights in the orbit plane of the star.