Quasar#Multiple quasars

As Doppelquasar quasars are called adjacent apparently or actually in the sky. It may be two or more different quasars, these are also called "real" quasars. Alternatively, it is also possible and even likely that it is a multiple imaging by gravitational lensing of a single quasar.

True Doppelquasare

As a "real" Doppelquasare are called two different quasars, which are apparently or actually adjacent in the sky. Quasar which are spatially adjacent to be referred to as " Quasar pair ". The first quasar pair was detected in 1987 by Djorgovsky. It involves the Quasarpaar OM -076 in the cup. Nine other cases have so far been documented. Because of their same distance from the Earth, they show the same redshift, their different chemical composition is shown in different electromagnetic spectra.

Since quasars are rare objects in the sky, the probability of three or more separate quasars can be found in the same place very low. The first true triple quasar was found at the Keck Observatory Mauna Kea, Hawaii, 2007. 2007 was discovered a third quasar in double quasar LBQS 1429-008. All three quasars a redshift of z = 2.076, which corresponds to a distance of 10.5 billion light years.

The individual quasars have a distance of approximately 30-50 kpc with each other, which is typical of interacting galaxies.

Multiple image of a Quasares

A single quasar can be multiply imaged by a gravitational lens. This quasar is referred to in English as multiply imaged quasar. Due to the gravitational lens may double, triple or quadruple images to the same quasar. The first object of this kind was discovered in 1979 with Q0957 561. A triple Quasar PG 1115 08 represents a quadruple quasar is the Einstein Cross, also Q2237 030 in the constellation Pegasus.