How close to each other are the stars? (APOD 17 May 2007)

[johnnyyooper]

when i see pictures of what appear to be densely packed star fields such as today's picture of the milky way, i wonder how close to each other those stars are. if i was on a planet in the midst of those stars, would i be seeing a lot of nearby "suns", say a few dozen, or would all the nearest stars still be pin points of light just as we see them from earth? (i'm not referring to double star systems here, rather the general density of the stars in what appears to be a much more densely packed array than where we are here in the our solar system.)
maybe another way to put my question is: are each of those tiny pin points of light really light years apart from each other ?

[rigelan]

http://zebu.uoregon.edu/~imamura/123/le ... bulge.html

I found that the average star density in our area of the milky way is about one star every 5 light years, or one star every 125 cubic light years. This equals 0.008 stars per cubic light year.

In the central bulge of the milky way there are on average 1600 stars per cubic light year.

My conjecture: I would imagine that all of the arms of the milky way also have sparsely scattered stars like our local neighborhood. And that they probably range from one star every 2 light years to one star every 10 light years.

I don't know offhand if this picture is headed into the galactic center, away from it, or off to the side, but I imagine all of the indivual stars that we can see are pretty similar to our home here.

[ean]

On another point I just wonder if these globular clusters are not failed galaxies. The original dust cloud was not dense enough to enable the super massive stars at or near the center to spin up the accretion disk which means that a black hole was not formed as there was not sufficient gravity. I guess I will have to go and find the relative motions to see if this is low.

Ean

[AZJames]

As I view the spectacular picture of the Globular Cluster M13, I imagine that the sight from a hypothetical planet at its core must be like Times Square on a busy night.

But a few quick calculations on the back of an envelope have convinced me otherwise. It turns out that the average distance between stars at the core of M13 is about equal to 100 times the distance between the Sun and Pluto. Now thats a whole lot closer than is Alpha Centauri from us, but it's still a long ways.

Even inside something like M13, space is mostly enpty (well, aside from Dark Matter, that is).

[NoelC]

Even inside something like M13, space is mostly empty...

...Which helps explain why hundreds of thousands to millions of stars still discretely exist after 13+ billion years, rather than having collapsed into a big blob (black hole).

I for one would LOVE to see a computer simulation of the motion of the swarm of stars in a globular cluster. Visualizing that motion would be quite a sight!

-Noel

[Qev]

Like this?

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

Oop, here's another one, in mpg format:

http://haydenplanetarium.org/movies/ava ... rclust.mpg

which is a simulation of 6144 stars in time-lapse, at 1000 years per second.

[BMAONE23]

Qev,
I like the second link better. http://haydenplanetarium.org/movies/ava ... rclust.mpg
One thing for certain, any planet in this region wouldn't have sustaining constellations (as we appreciate them) as the position of the brightest stars in their night sky would be constantly changing.