Re: Why don't we see star formation at the edges of black holes?

[Ron Ebert <ebert@CITRUS.UCR.EDU>]

At 09:49 AM 5/20/99 -0700, Roger Haar wrote:

> Lee
>        You are asking a number of interesting and in fact difficult
> questions.
> The full answer to some of these question require advanced college courses.
>
>        Concerning stars formation near black holes:  Most black holes are
> relatively small ( no more than a few tens of solar masses) and the matter
> that is falling in is coming from a binary companion star.  The infall rate
> is very small. I think the order of a few millionths of a solar mass per
> year.  I do not think there is enough mass near the event  horizon at any
> one time to create a star.  The huge black holes assumed to be at the
> galactic core long ago sucked in most of the surrounding matter that is easy
> to get.  Most of the surrounding matter goes into orbit about these black
> holes.  Some of the star formation in the galactic core probably is related
> to  strong gravitational fields,  but near the event horizon the actual
> density of matter is relatively low.

What you say is true, but there is an even more important reason why stars
would not form near a black hole's event horizon. The tidal forces are too
high. If anything like a star would form in that neighborhood, the tidal
forces would rip it apart immediately.


Ron Ebert
ron.ebert@ucr.edu
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