Einstein's Cross

image of a quasar

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]

References change

  1. Q2237+030 or QSO 2237+0305
  2. NASA and ESA (1990). "The gravitational lens G2237 + 0305". HubbleSite. Retrieved July 25, 2006.
  3. The Einstein Cross can be seen in Pegasus at 22h40m30.3s +3d21m31s.
  4. Crinklaw, Greg. "Focus on Einstein's Cross". Retrieved 2013-06-29.