KITP: planets in globular clusters!

The dynamics workshop in back, refreshed and ready to rock with yet more people in place.
This morning Melvyn tutors us on planets.
In globular clusters.

Planets in globulars clusters?!

From the CfA wallpaper collection - very nice images btw

Well, yes, maybe.
Or, more generally planets in very dense stellar associations.

Dynamically planets tend to get stripped quickly if they are orbiting at more than a few AU in a typical cluster.
But, planets closer in can stick around for gigayears, and those tend to be the ones we can observe.

We looked...

we found something interesting elsewhere...

Some systematic studies:

Hills 1984

Davies et al 2001

and Davies et al 2001b

Fregeau et al 2006

and Malmberg et al 2007

You may laugh...
but, there is some reason to think, seriously, that the Sun formed in a relatively dense star cluster - not a globular, clearly, but probably a fairly large and rich open cluster with several thousand stars within a parsec or two at early times.

So, contingent dynamical evolution is potentially important for planetary systems like ours in particular, and we have reasons, which we may get back to later, to think the Sun had some dynamical interactions at early times.
Our Kuiper belt is a bit messed up and kinky.
Maybe.