The Great Globular Cluster in Hercules (APOD 15 Nov 2007)

[dduggan47]

First post here but I really liked this picture.

"... approaching the cluster core over 100 stars would be contained in a cube just 3 light-years on a side. For comparison, the closest star to the Sun is over 4 light-years away."

This brought two questions to mind. If our solar system (and therefore we) were near the center of that cluster:

1) What would the sky look like?

2) How would the nearby stellar environment affect our solar system? Would it be less likely to have formed?

[20071116 Edited for spelling.]

[BMAONE23]

Welcome to tne forum!!!
To answer your first question, Imagine a sky with hundreds of stars, as bright as, or brighter than Venus. Add in the fact that these stars are in orbit around a gravitational barycenter which causes their postitions to move relative to each other over several years. (No discernable constellations EVER) Your star itself might even orbit within the cluster over the course of 30 or 60 years constantly changing your perspective of space.

[Case]

What would the sky look like?

Much more bright stars, but still dark at night.

How would the nearby stellar environment affect our solar system? Would it be less likely to have formed?

I suppose objects (planets) close to a star could still exist, but the outer objects (Kuiper Belt, Oort Cloud) might become balls in a giant pinball game.

[tkmoore1958]

Exactly what I've wondered. I wonder if someone has made a Java applet that could make a mini-planetarium of your computer screen, where your point of view is the center of a cluster?

[bystander]

Exactly what I've wondered. I wonder if someone has made a Java applet that could make a mini-planetarium of your computer screen, where your point of view is the center of a cluster?

You might try A Star Cluster in Motion (APOD 20020730)

[NoelC]

I spent time wondering what the sky would look like in there too. I'd think it would be quite spectacular indeed. Now and again you'd no doubt see other stars get fairly close, too.

Another aspect is that globulars have a lot of very bright red and blue stars. So there would be a lot of color in those shifting, very bright points in the sky. Lastly, there are quite a lot of variable stars, so some would brighten and dim - possibly even visibly in real time. Talk about twinkling! Christmas lights every night in the sky.

Taking this further... Imagine hundreds of stars within reach via interstellar space travel. Depending on what you believe, you could even imagine getting in two-way contact with other civilizations.

As globular clusters are widely thought to be very, very old, it's possible civilizations might even have mounted expeditions to other worlds in pursuit of survival, as their star began to exhaust its fuel...

No doubt some great science fiction could be written about life in a globular cluster.

Surely makes me wish I were there.

-Noel

[tom2688]

amen to that, noel. ( your last line!)

[hawkeye]

it occurs to me that Hercules, and other star clusters are ball shaped and therefore the center would always appear to contain a heavier concentration of stars than the outer edges. can the density of stars always be "counted" well enough to varify that the center is indeed more heavily concentrated and not just the effect of looking through the thickest part of the ball.

[Nancy D]

I wonder if a planet could exist, in that "crowded space", with those just-right conditions that we have here: temperature range, protective magnetic field, an atmosphere that stays put and having the right proportions of gasses, abundant water, and whatever else I'm not listing.

And I also feel very curious about what that night sky would look like. Stunning, I'll bet.

[BMAONE23]

Can an N-body Solver Program be utilized to show this type of simulation with the vantage point being the barycenter looking out?

http://antwrp.gsfc.nasa.gov/apod/ap020730.html

[dduggan47]

I wonder if a planet could exist, in that "crowded space", with those just-right conditions that we have here: temperature range, protective magnetic field, an atmosphere that stays put and having the right proportions of gasses, abundant water, and whatever else I'm not listing.

Yup, the "crowded space" is what I was wondering about too. Would a system like ours be pulled apart before it could even form?

And I also feel very curious about what that night sky would look like. Stunning, I'll bet.

This, of course, is the key question. The science is interesting but I'd pay big bucks for the picture!

[20071116 Edited because I can't type.]

[Daburb]

Just joined because I have such a DRIVING question (those that I can't figure out and it DRIVES me crazy!). The Hercules Globular Cluster picture is pretty amazing. When I read the specifics, it said that it was taken at Mount Palomar. I've been to Mount Palomar MANY years ago (1978) and the light pollution was bad then, how do they take such detailed pictures with what is probably MUCH more light pollution now? Thanks in advance!

Geoff Warnock

[NoelC]

The image is actually from fairly old exposures.

The Palomar folks did a very high quality survey of the sky several decades ago, through blue, red, and infrared filters, onto photographic plates. This is called the POSS2 survey. Since then, the Space Telescope Science Institute has scanned these plates and made the data available online. This highly accurate data forms, among other things, the basis of the database used to aim the Hubble Space Telescope.

It's also, with suitable processing, a great source of beautiful deep sky imagery.

There was some light pollution in the exposures, in addition to some satellite trails, all of which I removed digitally when preparing this image.

-Noel

[Daburb]

Noel - thank you for the PROMPT and informative reply. I can go to work now and concentrate on my job.

[Doum]

[quote="Nancy D"]I wonder if a planet could exist, in that "crowded space", with those just-right conditions that we have here: temperature range, protective magnetic field, an atmosphere that stays put and having the right proportions of gasses, abundant water, and whatever else I'm not listing.

I think that with so many stars in a close range some of them had or will be a nova or a supernova and that it will kill all life in there. If not then yea, space exploration between star in there might be a lot easyer then here and the sky must be wonderfull to look at.

[JohnD]

SF - life in a globular cluster.
Well, not quite, but Asimov did write 'Nightfall'.

As to what it might look like from inside a globular cluster, see: http://cfa-www.harvard.edu/common/image ... ar-800.jpg
Lots more lovely images there too!






Nightfall Spoiler Alert!




A story of a planet with multiple suns, whose orbit and rotation keeps at least one in the sky constantly. Except every few thousand years, when they all set at once. The resulting view of a starry sky has unexpected results for civilisation.

John