This Hubble image has fascinated me ever since I first saw it and I wondered if an amateur astronomer could detect anything at all of this Einstein Ring.  I was amazed to find I could, with only 3.5 hours of OSC data back in 2022 (see here https://x.com/clarkjames70/status/1552417220986388480?s=20) and only an 8" EdgeHD.

This led to Ollie @Ollie Aplin and I collaborating on a better image, now that we both had mono cameras and shared the fascination.

The Large Red Galaxy (LRG3-757) at the centre of the ring is gravitationally lensing the light from a far more distant and younger, hence bluer, galaxy directly behind the line of sight to my back garden, a great demonstration of Einstein's General Theory of Relativity's prediction of light being bent by gravity - in this case forming an almost perfect Einstein Ring.  Amazingly, it's still almost perfect when shot from Ollie's back garden, almost 200 miles away 

So, the blue light of the Einstein Ring started its journey 10.9 bn light years ago, less than 3bn years after the Big Bang (= the dawn of time!) and has been travelling for over 80% of the life of the universe, interacting with nothing, apart from the gravity of LRG3-757, until going SPLATT!! onto our camera sensors.
LRG3-757 is a trillion times the mass of the Sun, almost ten times bigger than our Milky Way galaxy and is 'only' 5bn light years away.  I'm not sure what is more amazing - that we can detect the galaxy forming the Einstein Ring with the help of the gravitational lensing from 11bn LY or that we can see LRG3-757 from 5bn LY away with no help from gravitational lensing.
It's astounding to note that when the light forming the Einstein Ring was bent by gravity, already over half-way on its journey, (and the light from LRG3-757 itself set off) the Earth and Sun did not even exist and would need another 500 mn years before their birth.

Clear skies were hard to come by but we collected 50h of Lum plus 5.5h of mono RGB to add to the original 3.5h of OSC colour data over 2023 and 2024.

More information on these incredible objects, discovered in 2007, can be found at this link, reproduced below for convenience:

https://www.universetoday.com/1928/the-cosmic-horseshoe-a-nearly-complete-einstein-ring/

If you want to peer into the furthest reaches of space, a regular telescope won’t do. You need to harness the power of a massive galaxy to bend light from an even more distant galaxy – a gravitational lens. And a team of European astronomers have found one of the luckiest discoveries of all, an Einsteinring, where the lens and more distant galaxy line almost perfectly. Because of its unique shape, they’re calling it “The Cosmic Horseshoe”.

The discovery was made by more than a dozen astronomers from a handful of European universities, from England to Russia. They published their discovery in a research paper called The Cosmic Horseshoe: Discovery of an EinsteinRing around a Giant Luminous Red Galaxy, which has been submitted to the Astrophysics Journal.

They turned up the object after poring through data in the massive Sloan Digital Sky Survey. This survey uses robotic telescopes to capture images of the night sky; eventually it will map out 25% of the sky, seeing 100 million objects. Astronomers regularly look through this vast quantity of data, and pull out all kinds of interesting objects.

Such as the Cosmic Horseshoe.

Then they did follow-up observations using the 2.5 metre Isaac Newton Telescope in La Palma and the 6 metre BTA telescope in Russia. This gave the detailed image attached to this story, as well as the spectral information to determine the chemical constituents of the lens and lensed object.

Look at the picture, and you can see a red spherical galaxy surrounded almost completely by a blue ring. In reality, this is a relatively nearby galaxy, located 4.6 billion light-years away (the lens), and then a more distant blue galaxy located 10.9 billion light-years away (the lensed object).

The two line up perfectly from our point of view, so that light from the blue galaxy is focused by the gravity of the lens. Light that would head off into space is turned back towards the Earth. All this additional light allows astronomers to see what would normally be an invisible object. In fact, the two are lined up so perfectly, that the lensed galaxy has been turned into a ring that wraps 300-degrees around the lens.

The lens is an extremely massive luminous red galaxy, containing 5 trillion times the mass of the Sun. For comparison, our own Milky Way only contains 580 billion solar masses.

And this is just the “telescope”.

The more distant, lensed object is a starburst galaxy undergoing furious rates of star formation – evidenced by the blue spectrum of its light. If it weren’t behind the lens, astronomers wouldn’t even know it was there. But because it’s directly behind the lens, its light has been focused into a nearly complete ring around the lens. Since it’s 10.9 billion light-years away, we see it at a time when the Universe was less than 3 billion years old.

This discovery gives astronomers two useful directions for further research: dark matter distribution around luminous red galaxies, and the formation of stars in the early Universe.