The liquid-water zone of a red dwarf hugs its star so tightly that any planet inside is almost certainly tidally locked, one hemisphere in permanent day. From O-type down to M-type the green band stretches with luminosity, and the flux relative to Earth is bracketed by the conservative limits S ≈ 1.1 inside and S ≈ 0.53 outside. Past either edge lie a runaway greenhouse and a snowball state, and as the host star ages and swells the whole band migrates outward.
The liquid-water zone of a red dwarf hugs its star so tightly that any planet inside is almost certainly tidally locked, one hemisphere in permanent day. From O-type down to M-type the green band stretches with luminosity, and the flux relative to Earth is bracketed by the conservative limits S ≈ 1.1 inside and S ≈ 0.53 outside. Past either edge lie a runaway greenhouse and a snowball state, and as the host star ages and swells the whole band migrates outward.
Related topics in Space