Thousands of stars within 6 LY of each other

[astrophoto]

I knew the Galactic center was dense, but WOW.<br /><br />http://www.space.com/imageoftheday/image_of_day_050211.html<br /><br />That picture on SDC shows thousands of stars within SIX ly of each other. That is simply incredible. I cannot even begin to comprehend the physics involved in how they interact or what kind of funky systems are tied together out there. Had to share my Wow.

 

[kmarinas86]

The Center of the Earth is too hot and dense, can't live there.<br />The Center of the Sun is too hot and dense, can't go there either.<br />The Center of the Galaxy too is very hot and dense, life can never form near it either.

 

[nexium]

Apparently our vicinity has hundreds of times lower density, so collisions, and near misses are very rare. Advanced life forms probably do not have time to evolve, in these high density regions, but colonies are possible, especially if the beings have means to survive all but the worst disruptions.<br /> In theory all the collisions and disruptions that can ocur will have occured after a very long time, but a massive intruder passing though can change several orbits renewing the collisions and near misses. Neil

 

[nexium]

Suppose we lived on a planet with two class m stars, occasionally (1% of the time) between one and two astronomical units away, two class k stars occasionally between two and three astronomical units, two glass G stars occasionally between three and four astronomical units, etc. It would be too cold most of the time, but occasionally it would get hot enough to melt the rocks, for a few days. Primitive life forms could survive only far below the surface, but who can say what technologically advanced life forms might have? I believe that would be thousands of times our present stellar density, but I don't know how to calculate it. Also I don't know how we can avoid super nova and a very rare class O star passing less than one astronomical unit which would cause the ablation of several meters of planet surface per hour. Please embellish, refute, and/or comment. Neil

 

[kmarinas86]

In Search of the Milky Way's Habitable Zone<br />http://www.spacedaily.com/news/life-01o.html<br /><br />If humankind could become like "gods" and establish life on other planets, then the size of the Milky Way's Galactic habitable would be not so restricted after all. Much of the restriction is time based.<br /><br />Our sun is surrounded by comets and any peturbation would cause life trouble. On the other hand, in the galactic center there are probably fewer comets because they would have already been taken down anyway.

 

[spayss]

Wouldn't there be frequent nearby super nova explosions and incredible radiation? Any life would be fried shortly after establishing itself.

 

[Aetius]

The center of the galaxy might be a good place for a civilization of self-aware machines to thrive. Plenty of available resources, and short distance between stars. Even the radiation might be prohibitively high for our kind of life to begin on an ocean world like Earth (were it located near the galactic core), but I think that it could be a vast power source for such hypothetical intelligent machines.

 

[alpha_taur1]

The question is, how far within 6 LY of each other? <br /><br />Our nearest star is about 4 LY (270,000 AU) away and that's a double system. If it's a hundred times more compact, that would place it about 2700AU from the sun. and if it was a thousand times more compact, that's 270 AU. <br /><br />That's well and truly close enough to have effects on the Oort cloud, which extends to around 100,000 AU, and possibly the Kuiper belt.<br /><br />

 

[astrophoto]

Ok so lets go with a number of 1000 as the number of stars in that system that are within 6 ly of each other. In 3d space, evenly spaced, thats a grid of 10 x 10 x 10 stars. Which means if perfectly placed, each star is what ... .6 ly away from each other? Now if there are 8000, that makes it 20 x 20 x 20 which makes them .3LY apart, right? Or am I way off?<br /><br />Of course in reality they are not spread perfectly, but I do not believe any star in this system is any further from another than these numbers would show. Thoughts?

 

[kmarinas86]

I think your calculations are on the mark:<br /><br />http://www.google.com/search?hl=en&lr=&q=.6+light+years+in+astronomical+units<br />.6 light years = 37 943.803 Astronomical Units<br /><br />This would put these stars at a distance 3800 times that of Saturn.

 

[astrophoto]

Thanks for the assurance. I am putting myself on a planet somewhere there and just trying to imagine what it would be like (assuming I was properly shielded). The night cycle would likely be super bright - perhaps as bright as Earth's day? With all of those close stars in the sky, it must be similar ...<br />

 

[kmarinas86]

<font color="yellow">Thanks for the assurance. I am putting myself on a planet somewhere there and just trying to imagine what it would be like (assuming I was properly shielded). The night cycle would likely be super bright - perhaps as bright as Earth's day? With all of those close stars in the sky, it must be similar ... </font><br /><br />It really depends on the size of the star. Stars in the center of the galaxy are much larger and brighter so that's probably why they look so close together in that photo. In such a place as the center of the galaxy, there are so many bright lights in the sky that there would be no night - given that the stars are very very bright. There would be lots of solar wind as well.

 

[tony873004]

<i>Apparently our vicinity has hundreds of times lower density, so collisions, and near misses are very rare. Advanced life forms probably do not have time to evolve, in these high density regions, but colonies are possible, especially if the beings have means to survive all but the worst disruptions. <br />In theory all the collisions and disruptions that can ocur will have occured after a very long time, but a massive intruder passing though can change several orbits renewing the collisions and near misses. Neil </i><br /><br />I think you are right about the frequent disruptions. I feel it is unlikely that planets exist around these stars. A near miss between two stars can strip both stars of all but the very closest planets. The ejected planets would then be in very chaotic orbits in the middle of this dense region of stars. They would probably collide with a star or be ejected out of the galaxy.

 

[spayss]

Maybe it's good not to have too many neighbors.<br /><br />http://news.bbc.co.uk/2/hi/science/nature/4278005.stm