Exo-planets around Red Dwarf Stars: Reasons to look for Co-orbiting Same-Size Planets
By Chris Hibbs
Same-size planets that orbit one-another around a common centre of mass would answer a lot of problems associated with Red-Dwarf stars, such as: tidal locking (because same size planets would tidally lock to each-other, thus blocking tidal locking of either one to the star); requirement of geo-thermal heating from gravity (because orbiting a common centre of mass translates to at least 2 frequencies of gravitational change, tidal effects on one another, and on each by the star); differentiation of Neptune-like detections from rocky (because the different densities should be analytically available in the case of co-orbiting same-size planets); etc
While it is reasonable to expect instances of this system to be very rare, that has to be balanced by the plausible distinctiveness of the signature such systems may leave in terms of gravitational 'wobble' on the star and/or the scope for simulation modelling. In the case of the former, wobbles on the star could feasibly have several cycles for each one orbit of the co-orbiting system. It could even be possible that some instances of apparently high orbital frequencies of 'hot-jupiter' gas giants around other stars, may be smaller mass co-orbiting planets at greater distance. in the case of simulation modelling, a rich diversity of possibilities may be revealed, in that systems of this kind would plausibly only need to enter the habitable-zone once per cycle for each of the two planets.
It's obviously possible and likely this idea is already in play. Apologies in that case.