Celestia Forums

As far as I've been able to see the theory for Pegasi-type planets is that the planet interacts with the dust disk and so loses angular momentum.

As it falls inwards, it would clear out the dust disk as it goes along.

So my question is: how does this explain 55 Cancri, where there are two such giant planets close to the star? Surely after the first one migrated inwards there wouldn't be a disk around for the second to lose angular momentum to, so it wouldn't move in...

Or would it happen simultaneously - how close could the two giants have been during formation, because I would have expected a gas giant to require a lot of room to form in, as they would disrupt the disk?

Aren't there supposed to be momentum transfers involving the star due to magnetic field interactions?

Apparently not in this case... See below.

http://arxiv.org/abs/astro-ph/0209125

claims that they could have been trapped in a 3:1 orbital resonance when further out and migrated in together.

selden wrote:http://arxiv.org/abs/astro-ph/0209125

claims that they could have been trapped in a 3:1 orbital resonance when further out and migrated in together.

Ok, thanks. I suppose something similar applies to the Upsilon Andromedae system where there are also two gas giants fairly close in.