Astronomers have discovered a new Einstein cross. This makes four identical images of one distant galaxy visible.
Scientists used the Very Large Telescope to observe the quadrilateral lens system. The object is named DESI-253.2534+26.884.
The red dot in the center is an elliptical galaxy. This galaxy has a very strong gravitational field. Light from objects behind the mass is bent. This has all kinds of consequences. In this way, the image of the galaxy can be enhanced, distorted or expanded. Sometimes it produces multiple images, for example in the case of Einstein’s new cross. Thanks to gravitational lensing, distant and invisible galaxies can be seen.
Because of the expansion of the universe, distant galaxies are redder than nearby galaxies. However, that kite does not apply to this Einstein cross. The galaxy at the center is much closer to Earth than a four-leaf clover. The four images of the distant galaxy appear bluer because there are many young stars in this galaxy. The foreground galaxy in the center is composed mainly of old stars, and therefore appears redder.
The world-famous Hubble image of Einstein’s first cross
in the paper The authors also briefly look at the history of Einstein’s crosses. In 1985, astronomers discovered the first Einstein cross: the Hochra lens (G2237+0305). Named after co-discoverer John Hochra, this galaxy is located 400 million light-years from Earth. Made in 1990 The Hubble Telescope captured this world-famous image of Einstein’s Cross. The four leaves consist of a quasar eight billion light-years away from us. The foreground galaxy is only 400 million away from our planet. After Hochra lens Many new crosses have been found.
What does Einstein have to do with the topic?
You may be wondering: Why is this thing called Einstein’s Cross? This is because Einstein’s cross is a perfect example of gravitational lensing. Albert Einstein published the theory of general relativity in 1916, in which he predicted, among other things, that galactic gravity could bend light, just as a glass lens does. Later this prediction came true.
