When we see a doubling of the image of single quasar, the body creating the gravity lens is just a brown dwarf close to us.

Question

Quizplus · Accepted Answer

The doubling of the image of a single quasar is typically caused by a much more massive object, such as a galaxy or a cluster of galaxies, acting as a gravitational lens. Brown dwarfs, while they can cause gravitational lensing, do not have enough mass to produce such dramatic effects observable from Earth.

When We See a Doubling of the Image of Single