Habitability HIP 57274 d

hip 57274 d resides in outer part of circumstellar habitable zone of parent star. exoplanet, mass of 0.527 rj, massive rocky, , because of planet may not habitable. hypothetically, large enough moons, sufficient atmosphere , pressure, may able support liquid water , potentially life. however, such moons not form around planets, have captured afar; e.g., protoplanet running astray.

for stable orbit ratio between moon s orbital period ps around primary , of primary around star pp must < 1/9, e.g. if planet takes 90 days orbit star, maximum stable orbit moon of planet less 10 days. simulations suggest moon orbital period less 45 60 days remain safely bound massive giant planet or brown dwarf orbits 1 au sun-like star. in case of hip 57274 d, moon s orbit have 40 days support stable orbit.

tidal effects allow moon sustain plate tectonics, cause volcanic activity regulate moon s temperature , create geodynamo effect give satellite strong magnetic field.

to support earth-like atmosphere 4.6 billion years (the age of earth), moon have have mars-like density , @ least mass of 0.07 m⊕. 1 way decrease loss sputtering moon have strong magnetic field can deflect stellar wind , radiation belts. nasa s galileo s measurements hints large moons can have magnetic fields; found jupiter s moon ganymede has own magnetosphere, though mass 0.025 m⊕.