Einstein cross

Meanings

1. A gravitational lens configuration resulting in four duplicated images of the back ground image around the central gravitationally lensing object, in a cross configuration.

1. A quadruply replicated image of a quasar, in the configuration of a cross, surrounding a central foreground galaxy which caused the replication through gravitational lensing.

Etymology

From Einstein (“Albert Einstein”) + cross. From the shape of a cross, of four points at roughly square angles around a central object, caused by distortions in the path of light's travel due to Einsteinian relativity (Albert Einstein's general relativity) creating four points out of a single light source behind the off-center central object. (An on-center central object results in an Einstein ring.).