Astronomers find planet with so many suns it shouldn't exist

Contributed by
Dec 17, 2012

We've seen a lot of incredible planet discoveries over the years, but this one's definitely among the coolest. It's a planet roughly the size of Neptune, but what makes it unique is the number of suns nearby, so many that the gravitational pull should destroy it.

The planet was discovered by Kian Jek of San Francisco and Robert Gagliano of Cottonwood, Ariz., two volunteer astronomers scanning data collected by NASA's Kepler Telescope made available through Planet Hunters, a website that allows astronomers from all over the world to aid in the search for new planets.

Dubbed PH1 in honor of Planet Hunters, the planet is believed to be a gas giant like Jupiter, Saturn and Neptune. It's a bit larger than Neptune, and six times larger than Earth, but what really makes it interesting are its four (yes, four) suns. Though we've known about binary systems (with two stars) for a long time, this is a different level of cosmic amazement.

"You don't have to go back too far before you would have got really good odds against one of these systems existing," said Dr Chris Lintott of the University of Oxford.

The four stars near PH1 include two suns that the planet orbits and two other suns that orbit the planet. It's a complicated collection of solar bodies, and with so many different gravitational pulls swirling around PH1 that scientists are still amazed the planet exists at all. How does it stay in the midst of all these suns without being pulled apart?

"All four stars pulling on it creates a very complicated environment. Yet there it sits in an apparently stable orbit," Lintott said. "That's really confusing, which is one of the things which makes this discovery so fun. It's absolutely not what we would have expected."

But because PH1 does seem to be surviving just fine while surrounded by four stars, Lintott and his fellow astronomers are hoping the planet will shed some light on how planets form and find stable orbits even in hostile environments.

"There are six other well-established planets around double stars, and they're all pretty close to those stars. So I think what this is telling us is planets can form in the inner parts of protoplanetary discs (the torus of dense gas that gives rise to planetary systems)," Lintott said.

"The planets are forming close in and able to cling to a stable orbit there. That probably has implications for how planets form elsewhere."

(Via BBC)