Mega planet discovered with rare triple suns

CAPE CANAVERAL, Fla. -- Three cheers for a newly discovered mega planet in the Constellation Centaurus that has not one, not two, but three suns.

Triple-star systems with detected planets are rare enough. But the giant gassy world in this one has the biggest known orbit in a multi-star system. Its orbit is double Pluto's -- or roughly 550 Earth years. That's how long it takes Planet HD 131399Ab to orbit its system's brightest star, a super-size sun.

During part of the planet's orbit, all three stars are visible in the sky on the same day, offering triple sunrises and sunsets. Other times, the planet enjoys continuous daylight.

A University of Arizona-led team used a telescope in Chile to spot this strange new world 320 light years away. The astronomers revealed their findings Thursday.

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  This image provided by the European Southern Observatory shows an illustration of the orbit of the gas giant planet in the HD 131399 system (red line) and the orbits of the three stars (blue lines). (ESO via AP)