Exoplanet is nearest of its kind with three suns

Exoplanet KELT-4Ab is nearest planet with three sunsResearchers from the Harvard-Smithsonian Center for Astrophysics have discovered a planet that has three stars, or should we say, three suns. And while this planet has been known to researchers since 1973, this new discovery marks the first time it has been proven to have three stars serving as its sun, instead of one.

The planet is codenamed KELT-4Ab, and according to study lead Jason Eastman, the fact that the exoplanet has three suns isn’t the strangest thing about his team’s new discovery. He told Gizmodo that the skies would also look quite different, but the timelines on the planet were even more unusual.

“You’d see the primary star about the size of your outstretched, splayed hand (about 40x the apparent size of our Sun),” Eastman told Gizmodo. “Your year and day would be the same: 3 Earth days, which means half of planet would be in continuous daylight and the other half would be in continuous darkness.

“You’d also see two points of light about 2 degrees apart, each as bright as the full moon (KELT-4BC). Those two points would orbit each other every 30 Earth years, and every 4000 years, they’d make a complete orbit in the sky (that is, for 2000 years, they’d rise during the summer and for 2000 years, they’d rise during the winter).”

KELT-4Ab is a gas giant not unlike Jupiter in terms of makeup and size, and among its three suns, the gigantic KELT-A serves as its primary sun. The much smaller twin suns KELT-B and KELT-C  are considerably farther away, and, as Eastman stated, orbit each other every 30 years or so. Scientists hope to glean more information on KELT-4Ab and its suns in future studies.

KELT-4ab isn’t the only planet with three suns in our universe; for example, the HD 1885 Ab star system is very similar to what Eastman and colleagues have discovered. KELT-4ab, however, is only 210 parsecs away, making it the nearest planet with a three-sun system discovered so far.