Discovery

The discovery of the Einstein Cross began uneventfully. In a routine redshift survey, a low redshift galaxy (z = 0.0394) of magnitude 15 was observed to have the spectrum of a high redshift quasar (z = 1.695) mixed up in the light of its nucleus. High resolution ground-based images then later showed the 4 QSO images arrayed around the nucleus of the galaxy, and Hubble Space Telescope WFPC2 images as in the left panel show faintly but clearly the lensing spiral.