Corey S PowellFeb 11, 2025

People have been observing galaxy NGC 6505 for 140 years, but only now noticed an "Einstein ring" at its center. There, gravity has bent and magnified another, more distant galaxy into a delicate ring of light.

The universe is full of beautiful, hidden surprises.

https://www.esa.int/Science_Exploration/Space_Science/Euclid/Euclid_discovers_a_stunning_Einstein_ring #space #science #photography

Euclid discovers a stunning Einstein ring

Euclid, the European Space Agency’s dark Universe detective, has made an astonishing discovery – right in our cosmic backyard.

Show threadmccFeb 11, 2025
@coreyspowell wait, so does this mean that galaxy has a black hole at the center, and is that a new observation (ie a galaxy which definitely, instead of by assumption, has a black hole at the center?)
Show threadrukenau

@mcc @coreyspowell Einstein rings are just generally how gravity focuses light. You could see Einstein rings around the Sun at the right distance away. That's what's behind the Solar Gravitational Lens idea - see for example https://www.universetoday.com/155642/using-the-sun-as-a-gravitational-lens-would-let-us-see-exoplanets-with-incredible-resolution

What this really means is that this galaxy is aligned with another in the distance. It's an amazing coincidence that lets us see further than otherwise possible.

Using the Sun as a Gravitational Lens Would Let Us See Exoplanets With Incredible Resolution

Have you ever seen wispy arcs and rings in astronomical images taken by the Hubble Space Telescope and other observatories? These unusual features are caused by a quirk of nature called gravitational lensing, which occurs when light from a distant object is distorted by a closer massive object along the same line of sight. This … Continue reading "Using the Sun as a Gravitational Lens Would Let Us See Exoplanets With Incredible Resolution"

Universe Today
Feb 11, 2025 at 5:26pmPachli
Show threadrukenauFeb 11, 2025
@mcc @coreyspowell It might not be impossible to prove the existence of a black hole. Someone with more general relativity knowledge than I have could probably calculate the curvature needed to produce this ring and compare it to the volume of space making it. If that's high enough, it would need to be from a black hole. That would still be indirect evidence, though. Light bends the same whether dark matter, star clusters, or black holes provide the gravity.