Time for questions!
Jeff Linsky kicks off by questioning how well we can extrapolate, given how different the magnetic fields of stars other than the Sun are known to be. Athanasios agrees that there are challenges, but is hopeful that more stellar CME (coronal mass ejection) measurement will help test the relation on stars.
When we normally think of exo planets that are habitable we think about them being in the habitable zone, then the potential make up of the planet (e.g rocky) then the potential atmospheric composiiton, I had not actually thought about magnetic fields protecting the planet, so thanks for this, another thing to think aboiut and consider when just chatting generally about this.
@astroilin On Earth an Ozone layer (O_3) is important, if I understand it correctly Ozone is formed due to the interaction between Oxygen (O_2) and high energy particles in the upper atmosphere.
I have just put the formulae in for completeness.
@zleap Yes, a lot goes in to making a planet habitable, all your points included! And we might well find more factors in the near future!