Amateur Planet Hunters Find First Planet In a Four-Star System

The Bad Astronomer writes "For the first time, a planet has been found in a stellar system composed of four stars. The planet, called PH-1, orbits a binary star made of two sun-like stars in a tight orbit. That binary is itself orbited by another binary pair much farther out. Even more amazing, this planet was found by two "citizen scientists", amateurs who participated in Planet Hunters, a project which puts Kepler Observatory data online for lay people to analyze. At least two confirmed planets have been found by this project, but this is the first — ever — in a quaternary system."

Re:Clearly this is Binar 0

[roc97007]

Or Asimov's Nightfall? (The story, not the movie.)

Pretty surprising

[Grayhand]

If planets can form with the gravitational forces of a dual binary system I have to believe virtually all suns have planets of some form. Stars tend to have left over material when they form and that tends to form planets. The more conditions they find that can support planets the more system candidates there are for planets.

Re:Six stars

[Neil Boekend]

Easy, the planet could have a slow rotation. The planet orbits two stars (who orbit each other extremely closely). At an orbit further out two other stars orbit the entire system of 2 stars and a planet. The large orbit of the "outer stars" means everything can be in such a configuration:
0 = star . = planet _ = space because nbsp's don't work

00 _ _ _ _ 00 .

This would give a night. Half a year later (from the planets POV)

00 _ _ _ . 00
and they have no night.

My question is: how can such a system be stable? The planet would have vastly different gravitational forces when it's between the starts as opposed to when it's not between the stars. I suppose the outer stars could be in an extremely big orbit (twice the size of Pluto's) so the effect would be slow, but I expect a great risk of orbital instability and thus crashing into the star or being flung out of orbit into the vastness of space. Neither are fun.