Aliens on This World Would See a Double Sunset

Imagine a world orbiting a star in a binary system. Two stars would shine in the day, and the rare nights would occur only when both stars had set below the horizon. Now astronomers have discovered a world where this is the case - the sunsets would be spectacular.

The planet is located in the gamma Cephei system, and has about 1.7 times the mass of Jupiter. It completes an orbit once every 3 years. Astronomers have known about the bright main star and its planet, but now they've been able to tease out images of a much dimmer second star.

The two stars are separated by only 20 times the distance between the Earth and the Sun. The brigher Cephei A has about 1.5 times the mass of the Sun, while the dimmer Cephei B has about half the mass of the Sun. The planet orbits the brighter star.

The images were captured using the Japanese Subaru telescope located in Hawaii, and the Calar Alto telescope in Spain.

Fraser Cain

Fraser Cain

Fraser Cain is the publisher of Universe Today, founding the website in March 1999. He's also the co-host of Astronomy Cast.