Ordinary people have spotted an extraordinary world: a giant planet larger than Neptune and smaller than Saturn that inhabits a star system with four suns.
The citizen scientists discovered the planet by examining data from NASA's Kepler spacecraft. Professional astronomers then confirmed the find, which they
submitted to The Astrophysical Journal. Named PH1, the planet goes around two of the four stars,
shown close-up here: One is a yellow-white F-type star that is slightly warmer and more luminous than our sun; the other, at the 11 o'clock position, is a
red dwarf, cooler and dimmer than the sun. The two stars orbit each other every 20 days. The planet is the round black dot at the 4 o'clock position. (The
black splotches elsewhere are starspots.) The planet goes around the stellar duo every 138 days—slower than Mercury (88 days), faster than Venus (225
days). At the 10:30 position, a second stellar binary appears, about 30 times farther away than Pluto is from the sun. At certain times of the planet's
year, those distant suns shine during the day; but at other times, they light up its night.
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