# [ExI] Silence in the sky-but why?

spike spike66 at att.net
Mon Sep 2 18:01:26 UTC 2013

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From: extropy-chat-bounces at lists.extropy.org
[mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of Alfio Puglisi
Sent: Monday, September 02, 2013 10:01 AM
To: ExI chat list
Subject: Re: [ExI] Silence in the sky-but why?

On Mon, Sep 2, 2013 at 4:48 PM, spike <spike66 at att.net> wrote:

I haven't worked out the details on whether colliding two stars would cause
a nova (note difference between nova and supernova.)  I suspect any star
collision would cause a nova, but that is not a show stopper I wouldn't
think.

Have you heard of "blue stragglers" ? Star merging may occur naturally in
sufficiently dense environments. See
https://en.wikipedia.org/wiki/Blue_straggler

Alfio

Cool thanks Alfio.  I did some BOTECs on this notion and found something
yesterday which they vaguely hint at in your article, the fast spin.  I was
trying to determine if the induced close encounter between two stars would
transfer mass from the smaller to the larger under all circumstances.  Turns
out it's the other way around under most circumstances as far as I can tell,
but what I was doing is figuring out if we could use angular momentum to do
what I suggested yesterday, create a smaller mass star while keeping our
modest forward speed, which took 20 million years to accumulate.

There is one other question I still have no insights on how to calculate.
If we induce a very close encounter between stars, transfer some mass from
the more massive star, we really get the less massive star spinning wildly.
That would (I think) cause that star to stay on the main sequence longer,
since its pressure gradient would be decreased: the center of that star is
at lower pressures than it would be if its sidereal motion is zero.

I will post later on that if I manage to model this successufully and solve
the equations, no guarantee.  Some of you hipsters, do feel free to scoop me
on that.

spike

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