Although Jupiter is the most similar planet in our solar system to the planet Anubis, one might argue
that a gas planet of its mass would be more closely related to the sun. Anubis has a mass of 50 times
MJ (the mass of Jupiter), approximately .05 MS (mass of the Sun). It is accepted that a gas planet of
84 times MJ, .08MS is required to have begun fusion at its core and become a star. The diameter of
Anubis is slightly larger than that of Jupiter, even though it is much more massive. This is due to
the unchecked gravitational contraction of the planet. In a star, the outward pressure of the fusion
processes in the core counteracts this contraction. In effect, Anubis is about as large as any gas
giant can be.
It is believed that Anubis has a small rocky core, more dense than Jupiter's core and composed of the
same elements, mostly Fe and Si. Anubis can be called a "super planet", a giant planet more massive
than Jupiter, because its core is rocky, its position in the plane of the other planets, and its
roughly circular orbit around the star. These characteristics are consistent with those accepted of
the formation and position of planets in our solar system. Even so, it is easier to relate Anubis to
a brown dwarf.
Anubis is very massive, about 50 times more so than Jupiter. A planet this massive would still be
generating a great deal of energy due to the gravitational compression of its formation. Even though
the age of the planet is nearly 5 billion years, the core temperature is about 1.8 million K and the
surface temperature near 1,800 K. The luminosity, energy radiated, is about 10e-5 that of our Sun.
Anubis is much more luminous than Jupiter, nearly 1000 times more. Indeed, if it were the same
distance away, a viewer from earth would have no difficulty spotting it. The luminosity will
continue to decrease as the core gradually cools.
Anubis has an atmosphere consisting of mostly hydrogen and some helium, similar to Jupiter, and most stars. Trace elements and compounds are like those found on Jupiter. While the exact proportions of the trace compounds remain obscure, one could expect these would also be similar to those of Jupiter. Due to its incredible gravity, Anubis is almost totally liquid with only a trace, less than 100 km deep, of a gaseous atmosphere above its liquid H2 surface. At a relatively small depth of the planet, the pressure is sufficient to produce the phase transition of the liquid H2 to liquid metallic hydrogen which composes most of the planet, and the state at which most of the hydrogen exists on the planet. Most of the helium, methane and trace compounds are expected to be in liquid or solid ice form, due to the pressures involved. Although much less striking, the surface appearance of the planet is similar to Jupiter. The varied compounds in the gaseous atmosphere will be different. This, as well as the limited depth of clouds and fog, results in some minor color variations. Also, the thin gaseous atmosphere will probably not exhibit the same prominent activity seen on Jupiter, however, there will be weather patterns due to convection are visible in the atmosphere due to the great internal heat of the planet.