[ExI] Planets galore!

spike spike66 at att.net
Wed Feb 8 16:57:11 UTC 2012



>... On Behalf Of BillK
Subject: [ExI] Planets galore!

Nomadic Planets May Swarm the Galaxy
<http://arxiv.org/abs/1201.2687>
<http://kipac.stanford.edu/collab/research/highlights/tidbits2012/nomads>

>>...We estimate that there may be up to ~10^5 compact objects in the mass
range 10^{-8} -10^{-2} solar mass per main sequence star that are unbound to
a host star in the Galaxy...  Complete pdf file
<http://arxiv.org/pdf/1201.2687>

===============

>...Can there really be up to 100,000 wandering planets for *every* star?
That's a mind-boggling big number of planets...BillK
_______________________________________________

It sure seems like there would be more than one nomad in orbit around the
sun outside the orbit plane of the planets.  We have Pluto/Charon which are
thought to be Kuiper belt objects, that are out of the plane, but those are
the only ones.  If there are really that many nomads we should have several
of them in the neighborhood, off the plane.  I haven't done the calcs on
this, but their notion might help explain the orbit velocity of stars as a
function of distance from the center of the galaxy.

The Strigari paper is very interesting and useful: their theory should be
testable with current instrumentation using short timescale microlensing
events.

I hope they are right BillK: in the long run, more metal in the galaxy is a
good thing.

spike



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