QUASAR QSO 0957+561

This 17th magnitude quasar is also known as the Double Quasar.  It is, in fact, a single quasar!  It's light is being gravitationally lensed by a massive galaxy situated half-way between the quasar and Earth, causing the quasar image to appear twice. The discovery of this 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 L 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."

That's OK Albert.  I've never seen this before either.

Redshift is 1.413 (lookback time is 8.7 billion LY)

The quasar separation is only 6 arc-seconds.  The full frame image is 22 X 15 arc-minutes. 

Meade 14" LX200GPS at f/5.87
SBIG ST-8XME  with adaptive optics
7 X 1 minute exposure, 2X2 binning, -20C cooling, 10 Hz guiding
Wishing Star Observatory

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