Einstein's Cross

This article is about the quasar. For the astrophysics concept, see gravitational lens.

Einstein's Cross ^[1] is an image of a quasar which is 8,000,000,000 light years (ly) or 2,500,000,000 parsecs (pc) away.

Einstein's Cross

The quasar sits directly behind ZW 2237+030, Huchra's lens, the lensing galaxy. Four images of the same distant quasar appear around this foreground galaxy due to strong gravitational lensing.

According to its redshift, the quasar is about 8 billion light years from Earth, while the lensing galaxy is only 400 million light years away.^[2]

Amateur astronomers are able to see some of the cross using telescopes but it requires extremely dark skies and telescope mirrors with diameters of 18 inches or greater.^[3][4]