Einstein's Cross

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.

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

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

[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.

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