On 04/04/2017 05:29, Mike Dworetsky wrote:
Steve Willner wrote:
In article ,
writes:
Is the NET angular momentum of a globular cluster of stars, zero?

I think that's the case for most clusters, but I vaguely remember
that there are a tiny number that show rotation. I might be mistaken
on either part of this.

As I recall dimly from either reading or hearing talks about this, Omega Cen
appears slightly oblate, although I do not know what if any radial velocity
observations confirm that this is due to rotation. And it may be the core
of a small galaxy captured by the MWG long ago, rather than being a
"classical" globular.

There was something in ApJ early stellar dynamics measurements mid
1990's showing that the luminosity oblateness varies with radius more or
less spherical near the middle and far out but oblate in between.

https://arxiv.org/pdf/astro-ph/9612184.pdf

They credit someone else in 1983 as having first measured the isophotes
in 1983 and claim mean 0.121 minimum 0 up to 2', maximum 0.25 at 10' and
then becoming rounder as you go further out. (see p6)

--
Regards,
Martin Brown