M13 Globular Cluster

[airbolt]

This is just a whimsical query . I have long been fascinated by the Globular Cluster M13 - from Earth it appears to be a hyper-dense star cluster . What would be the intensity of light within such a cluster ?( even assuming an earth style planet existed there ).

[Loosehead]

A globular cluster is just another galactic configuration. Ie a mass of stars in no particular pattern, unlike our own spiral galaxy. The density of stars is similar so I would expect to see a night sky of about the same luminosity. Possibly a bit brighter with more stars near the centre, as would be the case for our own galaxy.

[airbolt]

I hadnt realised that the density is no more concentrated than our own. I suppose its an effect of viewing it from far away.

[Loosehead]

It just emphasises the vastness of the galaxy and the intergallactic space in between. The closest star to us is 4 light years away, the galaxy is about 50000 light years across and from a distance would look like a mass of stars all close together and of course on a galactic scale they are close together but to us the closest star is unimaginably far.

[jake-the-peg]

If you've not come across Olbers paradox before you might want to think about why the sky is dark at all in M13 or here.

Stars are constantly putting energy into the universe by turning matter into energy, and there is no way for it to escape i.e. turn back into matter from energy.

Theres a much better explanation of the problem and solution that you might find interesting here:

http://www.arachnoid.com/sky/

[airbolt]

I must admit that i hadnt thought why the sky is dark at night - fascinating site , thanks!

[airbolt]

Sorry , I meant at all not at night .

[Clanad]

Actually the diameter of the galactic disk is closer to 100,000 light years...