# Resonances and the seven sisters recently discovered

In reference to the discovery of seven planets around Trappist-1, I'm just wondering if any of these planets are in an orbital resonance and if that is the case, what the implications for habitability on these planets, with reference to Io and Europa around Jupiter, would be? And could such a resonance account for the fact that such a compact system appears to be stable?

• If seven planets in such a close distance are all in resonance, it must be a very complex system of 42 resonances, each planet with every other one. I think a lot longer observation time is necessary to measure the orbits so precisely that all resonances may be found.
– Uwe
Feb 23, 2017 at 15:35
• There is near-resonance in our own solar system too, therefore it should count.
– Uwe
Feb 23, 2017 at 15:53
• @Uwe Oh, I found a downloadable version although I don't know if it's an exact copy.
– uhoh
Feb 23, 2017 at 16:09
• In the downloadable version I found that 34 orbits were measured, this should be long enough for precise results. If we multiply the orbital periods by 20, we get: 30(.2), 48(.4), 80(.8), 121(.2), 184(.2) and 247. That is very close to small integers. If we multiply with 100, we get only integers: 151, 242, 404, 606, 921 and 1235, but are these numbers still small integers?
– Uwe
Feb 23, 2017 at 16:17