APOD: M13: The Great Globular Cluster in... (2020 Mar 19)

[MarkBour]

... the virus is actually SARS-CoV-2. COVID-19 is the disease caused by that virus.

Thanks, a helpful correction. And it can help clarify what I'm talking about.

... One can think about whether the virus itself is viewed as the bad thing or whether it is the disease or pandemic we're living through that is so bad. I guess most of us would not view the virus, in an isolated test-tube, as bad in and of itself. Maybe. On the other hand, I think that both the disease and the pandemic are very awful and tragic things to us.

The part I'm leaving out there, and probably not something to explore in this forum, is that from other perspectives, not everything we find as evil, hurtful, and sad, will be viewed with the same conclusion. But I couldn't help it, because I've been thinking about this idea a fair amount lately.

[Chris Peterson]

... the virus is actually SARS-CoV-2. COVID-19 is the disease caused by that virus.

Thanks, a helpful correction. And it can help clarify what I'm talking about.

... One can think about whether the virus itself is viewed as the bad thing or whether it is the disease or pandemic we're living through that is so bad. I guess most of us would not view the virus, in an isolated test-tube, as bad in and of itself. Maybe. On the other hand, I think that both the disease and the pandemic are very awful and tragic things to us.

The part I'm leaving out there, and probably not something to explore in this forum, is that from other perspectives, not everything we find as evil, hurtful, and sad, will be viewed with the same conclusion. But I couldn't help it, because I've been thinking about this idea a fair amount lately.

Of course, humans might be the best thing that every happened to the virus. Whether we look at numbers or at mass, it seems clear that the Universe (or our little corner of it) was created for single-celled organisms and viruses. Everything more complex simply exists to serve them in some way.

[TheOtherBruce]

FWIW, "coalescing into a super star" generally isn't a thing colliding stars do. Instead, they tend to go boom. Very boom. All the boom.

Loved this description. Maybe it's a reference, too. It sounds familiar, but I don't recognize it.

I'm a big fan of both Babylon 5 (in particular the wit and wisdom of Susan Ivanova) and the webcomic Schlock Mercenary. The resulting mental car crash inspired me.

[Ann]

Can you explain;
Why with such a huge number of stars within very close proximity, has gravity not coalesced them into a super star.
Thanks

They are all in orbit. They don't coalesce for the same reason our solar system doesn't.

Though, like elliptical galaxies and utterly unlike the Solar System, a Galactic Cluster's components seem to move more like a bee swarm than a sensible planetary system. Stars orbit in 3D, sometimes in exceedingly thin, long ellipses and in chaotic ones heavily influenced by all of the millions of other stars whirling nearby.

Clusters are complicated dances of tiny, bright diamonds around a theoretical centre that may never be occupied by anything for very long. They are examples of the Many Body Problem written very, very large.

They are fun.

Click to play embedded YouTube video.

I thought I had already posted this video, but apparently not. I like seeing how stars move inside a cluster and how the stars evolve over time.

Ann

[MarkBour]

Of course, humans might be the best thing that every happened to the virus. Whether we look at numbers or at mass, it seems clear that the Universe (or our little corner of it) was created for single-celled organisms and viruses. Everything more complex simply exists to serve them in some way.

Loved this perspective. I wonder, will the viruses want us to carry them to the stars?

[MarkBour]

youtube -- https://www.youtube.com/watch?v=VF6J7P2cpn8

I thought I had already posted this video, but apparently not. I like seeing how stars move inside a cluster and how the stars evolve over time.

Ann

Thanks, a delightful simulation! It said "Rendered as you would see it with the Hubble Space Telescope, if it would snap a picture every 31250 year, that is!"

It's so nice to get to see things no human can ever actually watch.

[CuriousChimp]

Got a planetarium nearby?

Nope. Sorry.

You realize that you're just purposely making yourself feel bad, don't you? Actually, based on your last statement, I'm thinking you understood this already.

An interesting take on it. Maybe true, too.

I'm not sure I can explain myself, but what I feel I've come to realize lately is a paradox. There are lots of things in this universe that are inutterably sad. And I mean sad in reality, truly tragic. But then, after a longer reflection, it turns into a matter of perspective. Perhaps the greatest gift given to mankind is the ability to change our perspective, at will, with just a bit of effort. (Take the coronavirus COVID-19, for example. It's pure, pure badness, right?)

SARS mark 2 is not bad, evil or even judgemental, it's just a chemical reaction like a fire. What it does is sad, hurting people, but the bug itself is entirely neutral.

Lots of other things are like this, too. It is us that give meaning to them and only when they affect us.

But you're right, I'm feeling sentimental and maudlin and I need a hug. Sorry.

You explained yourself well.

[CuriousChimp]

They are all in orbit. They don't coalesce for the same reason our solar system doesn't.

Though, like elliptical galaxies and utterly unlike the Solar System, a Galactic Cluster's components seem to move more like a bee swarm than a sensible planetary system. Stars orbit in 3D, sometimes in exceedingly thin, long ellipses and in chaotic ones heavily influenced by all of the millions of other stars whirling nearby.

Clusters are complicated dances of tiny, bright diamonds around a theoretical centre that may never be occupied by anything for very long. They are examples of the Many Body Problem written very, very large.

They are fun.

<snipped>

I thought I had already posted this video, but apparently not. I like seeing how stars move inside a cluster and how the stars evolve over time.

Ann

Thank you, that's pretty.

[felix_wegerer]

Lovely object for apochromatic refractors! So many stars :0

[TheOtherBruce]

Click to play embedded YouTube video.

I thought I had already posted this video, but apparently not. I like seeing how stars move inside a cluster and how the stars evolve over time.

Interesting. Any guesses what the simulation did about 30 seconds in, when a bright giant and a smaller star went <p'ting> <zoom> off in opposite directions? Maybe a very close encounter that gave them both a gravity assist?

[Ann]

Click to play embedded YouTube video.

I thought I had already posted this video, but apparently not. I like seeing how stars move inside a cluster and how the stars evolve over time.

Interesting. Any guesses what the simulation did about 30 seconds in, when a bright giant and a smaller star went <p'ting> <zoom> off in opposite directions? Maybe a very close encounter that gave them both a gravity assist?

Exactly. In a crowded environment, stars may meet each other in just such a way that gives each of them a mighty boost in opposite directions.

Star formation in the Orion Nebula. NASA, ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team.

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Three runaway stars from the vicinity of the Orion Nebula, AE Aurigae, Mu Columbae and 53 Arietis. Graphic: Stellarium.

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Bob King of Sky & Telescope wrote:

So what caused the three to abruptly pick up and leave the scene? A supernova explosion might have sent the stars reeling in opposite directions, but recently discovered evidence points to gravitational interactions within a compact star cluster. It's thought that Mu Col and AE Aur once shared company as a binary system that collided or strayed too close to another binary pair. Complicated gravitational interactions ensued, breaking the binary's bond and flinging the stars into space as "runaways" while leaving the other binary intact, still lurking near the scene of the crime.

If you've ever observed the beautiful, 3rd-magnitude triple star Iota Orionis located just south of the Orion Nebula, you've caught the culprit red-handed. Besides its telescopic partners, Iota also possesses a massive, spectroscopic companion that revolves around the primary star in a highly eccentric orbit with the same velocity as runaways Mu Col and AE Aur. This and its location are important clues that tie Iota Ori to its distant cousins.

Ann