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View Full Version : Question From The Teeming With Black Holes Thread.



BigDon
2018-Jun-15, 09:32 PM
Started to ask it there and though brief, I then felt it was tidier in its own thread.



From here (http://www.astronomy.ohio-state.edu/~ryden/ast162_7/notes31.html), I see that the density of stars near the center is about 10 million stars per cubic parsec. Further down on the page, there's a calculation that shows that if the black hole has been growing at a steady rate over its lifetime (and if we assume that its lifetime is about the same as the Milky Way itself), that works out to about one solar mass of material every 5,000 years. It's possible that over a very long time period, you could end up with the area right near the black hole becoming mostly depleted of matter (when everything that has a trajectory that might take it too close has already been absorbed, and any galactic collisions that might change trajectories so that they come too close become rarer than they are today), but I think that this would take longer than the current age of the universe.

Good Lord, Grey.

If evenly distributed, what would be the mean distance between stars at that density?

A couple of astronomical units? (:))

Shaula
2018-Jun-15, 09:41 PM
10 millions stars would be a cube of stars 215 x215 x215 (roughly). So there would be 215 stars per parsec, or one every 960 AU.

BigDon
2018-Jun-15, 10:04 PM
Thank you Shaula!

Those are Firefly densities! :)

publiusr
2018-Jun-23, 08:08 PM
Lots of opportunities for gravity assist around the galactic center, it seems.

DaveC426913
2018-Jun-24, 02:10 AM
Lots of opportunities for gravity assist around the galactic center, it seems.
Well, that door would swing both ways, wouldn't it!

You'd gravity assist off one star, only to be slowed down by five others in your path...