UKC

A while ago, when exoplanets could be counted on the fingers of cornish hands, we had this thread:

http://www.ukclimbing.com/forums/t.php?t=367843&v=1#x5347557

Now there is a rather larger sample:

http://www.bbc.co.uk/news/science-environment-24549384

So I'd be interested to know what the frequency is of matching/counter-matching orbits of exoplanets to their sun's rotation?




Just 'phone Coel?

Ok, sorry to waste your time.

In reply to JJL:

For most of that sample we don't know, since it can only be discovered by watching the shifts in the spectrum of the star as a planet transits across it. The means we only know whether the orbit is prograde or retrograde for planets that are transiting (about 200 of the above sample), and are orbiting relatively bright stars (down to about 100), and where the above measurements have actually been done (down to about 40 off the top of my head). Of those about 5 are retrograde, so the retrograde ones are a minority and most are prograde.

In reply to Coel Hellier:

So 2 in 12 has become ~5 in~40, thanks!