The mass of the star proxima centauri is 12% of the mass of the sun. what would be the likely impact on the motion of earth if the sun were replaced by proxima centauri? a day would be shorter because the gravity experienced by earth would be stronger. a day would be shorter because the gravity experienced by earth would be weaker. a year on earth would be longer because earth would move relatively faster in its orbit. a year on earth would be longer because earth would move relatively more slowly in its orbit.