Generally, the planets are orbiting around their stars and no astronomers have detected the opposite situation……..but the space is full of mystery and strange things Please Register or Log in to view the hidden image! so, can the star in principle orbit around the planet? Of course such star should have less mass than planets, so the star should be the dimming white dwarf and the planet-gaseous giant with the mass much more than Jupiter have........is it possible? Please Register or Log in to view the hidden image!
Nope. A White dwarf, while small in size, is very dense and would have a mass similar to the Sun's. The smallest body that could be considered a star is a Brown dwarf. While there isn't a strong consensus of where in the terms of mass an object stops being a large planet and starts being a Brown dwarf, you are not going to get a situation where a planet is more massive than the Brown dwarf. Either the more massive body will be the star and the other a planet, or both will be classed as stars or both will be classed as planets.
Well technically speaking the Sun does orbit Jupiter, so there you go. Imagine if the solar system consisted of just Jupiter and the Sun. They would both orbit about a common barycenter. The Sun is so massive, however, that the barycenter actually lies within the body of the Sun. The Sun and Jupiter would orbit this barycenter. As a matter of fact, this is one method used to find extrasolar planets by measuring the 'wobble' of distant stars using doppler shift. In reality there are other planets that further complicate what would be simple, easy to solve orbits. I may be wrong on this Janus58, but I believe what qualifies a star is fusion in the core. So the question may then become, "Could the semimajor axis of a planet orbiting a barycenter ever be less than the semimajor axis of the corresponding star." In other words, could the sun appear to orbit the planet. In Newtonian physics, which of the two has the greater semimajor axis is only dependent on the mass. So if the planet were more massive than the star, then the answer is yes. However, if the planet were more massive than the star, then fusion would also likely occur in the planet. This would qualify the 'planet' as the second star in a binary star sytem. We are speaking of Jovian planets only here. So the answer is probably no. I can think of a few special cases that may qualify, but likely don't occur. Maybe another member can come up with some ideas...
Star planet systems orbit around a common center of mass. However this isn't as interesting as say a star rotating around a planet. When a planet gathers enough mass it begins to fuse hydrogen in it's core. Once fusion starts it becomes a star. So by definition no planet can have a mass greater than the mass of its star, resulting in the planet ALWAYS orbiting the star. http://www.google.com/url?sa=t&sour...m6CmAQ&usg=AFQjCNEp60sJHp3SvfSw_CU9P2yloDxlMQ
