Space is awesome
But capturing mass from another galaxy and ending up with a near-perfect ring ? The odds must be properly astronomical.
I can't wait for the explanation on this. It cannot not be interesting.
A rarer-than-rare galaxy 359 million light years away from Earth has been spotted by physicists. Designated PGC 1000714 [paywalled], the galaxy is a ring-shape system orbiting a cooler centre without any connection between the two – a formation referred to as Hoag's Object. Just 0.1 per cent of all observed galaxies are Hoag- …
Take a look at the asteroid belt, or the rings of Saturn. Gravity is good at making rings.
Take a look at Jupiter, the trojan asteroids, and Saturn's shepherd moons for why gravity alone isn't what makes rings stable. If we saw a galaxy like this with whatever the galactic-scale equivalent of a shepherd moon would be, the only thing which would fit the bill is a supermassive black hole. We know these exist a the centre of most, if not all, galaxies (including our own), but ring formation a-la-Saturn would require another in orbit close to the ring (or more likely a pair, one inside and one outside). Supermassive black holes, despite their name, do tend to be somewhat conspicuous, even when not actively consuming matter, due to their gravitational lensing effect. On this scale, too, they would probably have to be moving at a relativistic speed to keep a ring stable.
near perfect circle?
So... someone correct me if I'm wrong... but in order to have a perfect circle, we would have to be viewing the orbit directly perpendicular to the object. Like you're looking down the barrel of a gun.
So... now there's a blue shift? ... meaning objects are approaching?
It may be worth noting that random collisions of various gasses coming out of my ring during the recent feeding-frenzied festive period, whilst not exhibiting exactly the same visual results to those shown above, did, however, cause dramatic acceleration upon nearby relative objects (aunts and uncles etc) which were seen to separate away from the center of the event described at dramatic speeds not previously observed. Just saying.
Yes I know a physical connection was meant
What's a physical connection when it comes to astronomical objects? Hint: you have 4 forces to choose from of which 2 are available at large scales, gravity and the EM force. Usually, gravity is by far the most important.
Physics: being counterintuitive since De revolutionibus orbium caelestium and getting more so as time goes on.
Probably don't need an ethernet connection any more - any advanced civilisation would use something like zigbee, a secure ring of things if you like. All that taught redundant cat 5 might account for the circularity though ...
All your galaxies are belong to us ...... Plz pays 6 ninghies for usz to unlocks .....
So one in a thousand (0.1 per cent) is considered ultra-rare and/or rarer-than-rare? Not quite as rare as say carbon dioxide in the atmosphere at 400 ppm (0.04 percent). Yet there are two of these rare objects shown in the cover picture.
And why use "0.13 billion years" for the ring's age, is it more meaningful than say "130 million years old"?
Classic bulls-eye. I shudder to think of what's being fired at it, but I'm glad it's far away.
Perhaps someone with a better grasp of astrophysics would know if there's any chance of an orbiting black hole sweeping a clear lane? That would surely be a rare event if so. Not an informed guess, just noodling...
Actually you may be on target. Galaxy sims show that when a massive object (big black hole or small galaxy) passes thru a disk galaxy near the center and perpendicular to the disk plane, the mass of the intruder tends to draw in some of the target galaxy radially as it goes thru.
The intruder then continues on, leaving a lot of mass with a large inward radial component. The stars and gas clouds will first contract to a small ring (prevented from making a tiny clump due to angular momentum) and then that radial component changes sign and the small ring expands into a very large ring.
The ring's gas and dust collides with other gas clouds on the way out and triggers hot star formation in the ring's outer edge.
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