Gravitational Microlensing by Black Hole (illustration)
Depicts: Gravitational microlensing
Copyright: NASA
Though the angular separation is shown here, it is 100 times smaller than what HST can resolve. Hence the phenomenon is called "microlensing". HST and other telescopes instead see a brightening of the Star as the black hole drifts by, but they do not resolve the multiple images.
Last Update: 1 September 2019
