Gravitational lensing has to be one of the most visually striking phenomena in astronomy
Gravitational lensing is a phenomenon where a massive object bend the light of a distant source as it approaches the observer. Most often this takes the form of enormous galaxy clusters bending the light of even more distant galaxies into warped images of their true selves. They typically follow an arc around the massive object in the foreground like ripples in a pond.
Here's a few of my favourite gravitational lensing events.
Abel 1689 – Virgo
Abel 1689 is a one of the largest galaxy clusters in the known universe. It's located about 2.459 billion light-years away in constellation Virgo. Not only is this image visually beautiful, but the sheer number of gravitationally lensed galaxies across the entire image is just mind-blowing.
In 2008, one of the lensed galaxies, A1689-zD1, became known as the most distant galaxy from Earth based on a photometric redshift. 2008 also happens to be the same year the astronomy bug really bit me and it became one of my life-long passions.
PSZ1 G311.65-18.48 is a massive galaxy cluster located 4.6 billion light-years away in the constellation Apus. What's especially remarkable about this image is that it features a bright galaxy that's been lensed 12 separate times along four arcs. Three of these arcs are visible to the upper right of the cluster, while a fainter fourth arc is partially obscured by a bright foreground star to the bottom left of the cluster. This galaxy is almost 12 billion light-years away from Earth, which given its title as the brightest gravitationally lensed galaxy is quite a remarkable feat.
I don't talk about astronomy nearly enough, so let's change that!
One of the most groundbreaking developments in astronomy has been the absolutely mind-blowing work the James Webb Space Telescope has been putting out in a fraction of the time it took the old Hubble Space Telescope to produce similar work. Here are a couple of recent images I find particularly remarkable.
S1 LMC N79 – Dorado
Honestly, this image is just beautiful to look at. It’s even more breathtaking when you consider that this is just one cloud within this star-forming region of the Large Magellanic Cloud, which itself is an irregular galaxy located about 163,000 light-years from Earth. If you live in the Southern Hemisphere and find yourself a suitably dark place, you can gaze up and see this whole other galaxy as a milky blotch in the night sky.
A gravitationally lensed supernova in MRG-M0138 – Cetus
It's pretty wild seeing the immense force of gravity contained within these galactic clusters warp distant points of light in these visually striking ways. Each arc is a galaxy far beyond the cluster itself that allow us to peer further back in time. Sometimes these warped images mirror themselves on the complete opposite side of the cluster, like ripples on a pond. In the case of this distant supernova, the light emanating from that cataclysmic event is being reflected in such a way that it's reappearing further down the length of the arc, making it seem as though there are two supernovae happening when in fact they are the same.
Calling it "communication" may be a bit farfetched for anything that far away and because the alignment with stars is only temporary. It does makes it possible to transfer our history in an efficient way though.