
Hoag's Object - ani-ani
https://en.wikipedia.org/wiki/Hoag%27s_Object
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CliffStoll
As a summer student at Kitt Peak Observatory in 1974, I had the honor of
working with Art Hoag. Not just a brilliant astronomer and a super efficient
observer. Art was a true gentleman of the old school: kind to students and
quite progressive. Forty five years ago, over night-lunch at the observatory,
he told us of the importance of bringing into astrophysics more women,
minorities, gays, and foreign students.

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michaelmcdonald
Wait....Is this the account of THE Cliff Stoll? Author of “The Cuckoo’s Egg”?

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hanniabu
For those not aware of this book, I just looked it up and found a video
enactment of it starring cliff Stoll on Youtube. Started out slow, but after a
few minutes in when they started getting into the details I was hooked. Looks
like I just lost an hour tonight, lol.

[https://www.youtube.com/watch?v=qubEamdc4Ng](https://www.youtube.com/watch?v=qubEamdc4Ng)

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mkaic
Very cool that there’s a second ring galaxy you can see by looking through the
first one! And here I was not even knowing ring galaxies existed until today!

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bmgxyz
It's neat that such an interesting and pleasing object just happens to be
facing us.

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martinpw
Maybe that is a selection effect. Objects like this that are more inclined
will tend to look more like regular galaxies so will not be identified as ring
galaxies so easily.

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finnh
well sure.. but if one average an arbitrarily chosen vantage point (ours) sees
only one of these so well, then we can infer that many other arbitrary vantage
points see none. and that would be sad.

(i know the article mentions others, so this might not hold up to a full
cataloging of our night sky)

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dontbenebby
Wikipedia is usally pretty comprehensive but seems to list much less ring
galaxies than spiral galaxies:

[https://en.wikipedia.org/wiki/List_of_ring_galaxies](https://en.wikipedia.org/wiki/List_of_ring_galaxies)

Compare with "list of spiral galaxies" \- shorter by far.

[https://en.wikipedia.org/wiki/List_of_spiral_galaxies](https://en.wikipedia.org/wiki/List_of_spiral_galaxies)

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zabzonk
A somewhat bigger Ringworld?
[https://www.wikiwand.com/en/Ringworld](https://www.wikiwand.com/en/Ringworld)
Which, by coincidence, I am currently re-reading.

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sneak
A classic! I’m working on the Culture novels now, which have their own variant
(“orbitals”), minus the shadow squares or central star. Can’t recommend them
enough, so far.

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mkl
Orbitals, while enormous (greater surface area than earth), are much smaller.
The Culture novels do have Ringworld-sized rings as well, though. E.g. from
Consider Phlebas, flying under the orbital Vavatch: "It was like flying
upside-down over a planet made of metal; and of all the sights the galaxy held
which were the result of conscious effort, it was one bested for what the
Culture would call gawp value only by a big Ring, or a Sphere."

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phkahler
This structure seems like it should not be stable. If the middle part were not
centered, it would be gravitationally attracted to the ring.

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AnimalMuppet
If I understand correctly, the middle part _far_ out-masses the ring. If the
middle part were not centered, then the ring could continue to peacefully
orbit it, as the planets orbit the sun, even though their orbits are not
(quite) centered on it.

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phkahler
Ok, then the ring would be pulled in. But only to the extent that it behaves
like a solid which it isnt.

