On the hunt for Goldilocks (assuming nonvenerean), one more factor must be the planet's age, mass, and composition. This isn't so much the problem for the whiter suns, which burn out faster than the planet will; but it starts to hit home with the G class's planets. Like ours.
The issue is that without plate-tectonics, carbon stops entering the atmosphere and the planet gets cold. I'd worry about the dynamo keeping the rads out but that's just me [TOUGHSF 5/8: convection is 80% outer-core but still core]. Anyway they just care about the mantle, not [any part of] the core.
They bemoan that they cannot tell the composition of a planet's mantle. We actually... can, but only for the dead stars which we can spot chewing up those planets. Mostly hot white A class in life.
The study claims that Earth-mass planets should run out of radioactives in 2 billion years; the heavier Earthlikes more like 5-6. I must point out here that our planet is... fine. This may be because we have the core of a larger planet, having ejected our silicates up to our Moon.
The more-numerous K stars supposedly "goldilocks" include some fairly elderly systems, on that main-sequence for longer. Luckily there are more of them.
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