This is a stack of 8 3-minute subs taken with my 10"RC scope at L=2000mm, 0.55 arcsec/pixel.
Light from a single quasar perhaps 8 billion ly distant is gravitationally lensed by a galaxy cluster some 4 billion light years away, between us and the QSO, causing the quasar image to appear twice, at a separation of about 6 arc-seconds. The discovery of the object in 1979 provided the first direct evidence for the gravitational lensing effect predicted by Einstein, who concluded his 1936 paper Lens-Like Action of a Star by the Deviation of Light in the Gravitational Field saying
Even in the most favorable cases the length I is only
a few light-seconds, and x must be small compared
with this, if an appreciable increase of the apparent
brightness of A is to be produced by the lens-like
action of B.
Therefore, there is no great chance of observing
this phenomenon, even if dazzling by the light of the
much nearer star B is disregarded.
Inverted:
Some of the galaxies in the lensing cluster are just starting to rise out of the noise. I'm not sure if I'll have time to get more exposure time on this object this season, so here it is anyway.
I cropped and oriented the full frame image to match this Hubble image. The description of the Hubble image says the gravitationally lensed quasar is 14 billion light years distant, oops. Other sources give the distance as 7.8, 8.7, 8.9, or 9.1 billion ly.