70 Virginis b was one of two planets announced by Marcy and Butler in early 1996. The announcement swelled the ranks of then known extrasolar planets to three. Not as brutally hot as 51 Pegasi b and not as cold as 47 Ursae Majoris b, 70 Virginis b was believed to exist in a more temperate orbit that might have allowed liquid water to form on its moons. This fact led the planet to be unofficially dubbed "Goldilocks" by its discoverers. But ten years and one hundred and fifty planets later, studies of temperature and atmospheric structure paint a different view of 70 Vir b. Gone are visions of Earth-like moons orbiting a superjovian with a banded, cloudy atmosphere. With an average temperature of 477 K, the planet is too hot for water to form clouds and too cold for silica to condense. Thus, 70 Vir b is a Goldilocks of a different kind, a cloudless blue world looking more like Neptune than Jupiter. 70 Vir b is massive enough to be neither tidally locked by its star nor have any significant limits placed on the mass of its moons. The planet may very well have moons as massive, or even more massive, than Earth. But such Earth-mass moons would not be water strewn paradises. The same hot temperatures that dispel the planet's clouds also make it unlikely for liquid water to exist on any of its moons. In fact, such moons are probably free of water of any kind, as water would have long ago been photodissociated away by the ultraviolet light of the planet's G4 star. This means that any massive moons of 70 Vir b are more likely to be Venus-like than Earth-like. Its also possible that any inner moons of 70 Vir b might be tortured by tidal forces from both the planet itself and from more distant outer moons. Like Jupiter's Io, the inner moons would be highly volcanic. Unlike Io, those volcanoes would consist of molten rock, rather than sulfurous ices. These volcanic rocky moons may even periodically disgorge seas of magma on to their surfaces. With a mass of 7.44 Jupiters, 70 Vir b is one of the more massive extrasolar planets. Given the uncertainty of its orbit's inclination from the point of view of Earth, it may be even more massive. Indeed, in 2000, preliminary astrometry observations by Han et al suggested an inclination of 16.1o, which would give the planet a mass of 27 times that of Jupiter. Such a high mass would make 70 Vir b a brown dwarf rather than a planet. Despite its large mass, 70 Vir b is probably old enough to have cooled down significantly. The planet evolution model of Burrows et al suggest it has an effective temperature from internal heating of only 209 K, which is less than the 477 K the planet would receive from its star. Even if 70 Vir b has a mass of 27 Jupiters its effective temperature from internal heating would still be only 436 K. So even if the planet is really a brown dwarf, its appearance is still likely to be a cloudless blue.
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