> Once they found it in the 2016 images, the astronomers found it in other data as well. The apparent brightness of the star changed over time in the images. While a blue supergiant can change its brightness, it’s more likely LS1 is moving as it orbits the center of its own galaxy, and as it does so the effects of the gravitational lens change.

Can gravitational lensing really affect the brightness of an star traveling around a galaxy within a few months timespan?