<P> As quasars are rare objects, the probability of three or more separate quasars being found near the same location is very low . The first true triple quasar was found in 2007 by observations at the W.M. Keck Observatory Mauna Kea, Hawaii . LBQS 1429 - 008 (or QQQ J1432 − 0106) was first observed in 1989 and was found to be a double quasar; itself a rare occurrence . When astronomers discovered the third member, they confirmed that the sources were separate and not the result of gravitational lensing . This triple quasar has a red shift of z = 2.076, which is equivalent to 10.5 billion light years . The components are separated by an estimated 30--50 kpc, which is typical of interacting galaxies . An example of a triple quasar that is formed by lensing is PG1115 + 08 . </P> <P> In 2013, the second true triplet quasars QQQ J1519 + 0627 was found with redshift z = 1.51 (approx 9 billion light years) by an international team of astronomers led by Farina of the University of Insubria, the whole system is well accommodated within 25 ′ ′ (i.e., 200 kpc in projected distance). The team accessed data from observations collected at the La Silla Observatory with the New Technology Telescope (NTT) of the European Southern Observatory (ESO) and at the Calar Alto Observatory with the 3.5 m telescope of the Centro Astronómico Hispano Alemán (CAHA). </P> <P> The first quadruple quasar was discovered in 2015 . </P> <P> When two quasars are so nearly in the same direction as seen from Earth that they appear to be a single quasar but may be separated by the use of telescopes, they are referred to as a "double quasar", such as the Twin Quasar . These are two different quasars, and not the same quasar that is gravitationally lensed . This configuration is similar to the optical double star . Two quasars, a "quasar pair", may be closely related in time and space, and be gravitationally bound to one another . These may take the form of two quasars in the same galaxy cluster . This configuration is similar to two prominent stars in a star cluster . A "binary quasar", may be closely linked gravitationally and form a pair of interacting galaxies . This configuration is similar to that of a binary star system . </P>

What does a quasar look like when viewed through an optical telescope