Astronomers Found a Gas Giant Orbiting Surprisingly Close to a Tiny Star

[Judi Lynn]

Astronomers Found a Gas Giant Orbiting Surprisingly Close to a Tiny Star
5/02/15 4:00pm

Astronomers watching a small red dwarf star 500 light years away were surprised to notice a brief dip in its already dim light. But they quickly identified the source of the change: the darker mass of a planet passing between the distant star and our vantage point on Earth.

The star HATS-6 is about half the size of our Sun, in both mass and diameter. It is one of the smallest stars astronomers have seen with a gas giant, and apparently, our models can’t yet explain how this gas giant came to be so close to its parent star.


The planet in question (HATS-6b) weighs in at approximately the mass of Saturn, or 100 times the mass of Earth. But because of its close orbital distance, the star’s heat has caused HATS-6b’s gas to billow out, inflating the planet like a hot air balloon to the size of Jupiter. With an orbital period of just 3.3 days, astronomers say HATS-6b is significantly closer to its star than the much smaller Mercury is to our Sun.

When solar systems develop, gas giants usually form in the outer regions, where gas and ice are more abundant, but they don’t always stay there. Sometimes, thanks to gravitational nudges from other objects, they migrate inward to orbit very close to their stars. This happens as a normal part of the process of planets settling down into stable orbits.

More:
http://gizmodo.com/astronomers-found-a-gas-giant-orbiting-surprisingly-clo-1701634190

[bulloney]

1. The gas giant was Rush Limbaugh walking around tiny star Dennis Miller.