Space has a way of fooling the eyes. Consider the following picture – does the brilliant cluster in the middle represent a single galaxy, two, or maybe a half-dozen?
You are correct if you guessed two galaxies. These are the dots in the ring's center. However, what are the other four brilliant points of light that round them?
The four sparkling dots on the ring are nothing more than reflected light. They become visible due to a phenomenon known as "gravitational lensing." The term "Einstein Ring" refers to this form of gravitational lensing.
Gravitational lensing occurs when massive, distant space objects bend spacetime in such a way that the light in their vicinity looks physically warped from our vantage point on Earth.
Perhaps the most direct approach to witness this phenomenon is via Einstein's Rings. They occur only when two objects are precisely aligned – one behind the other, from our perspective.
This is the whole picture of the most recent ring observed by Hubble. It was released on August 9, 2021.
Additionally, there is another component to this optical illusion: a large quasar is nestled in the ring's core, lighting the whole cluster.
Quasars are extraordinarily luminous objects found at the heart of certain galaxies. They are formed when gas and dust collide with supermassive black holes, producing electromagnetic radiation in the process.
There is much more to those far-flung flecks of light than meets the eye. Additionally, you may thank Einstein for providing the explanation.
Reference(s): NASA