Double Date: Two Pairs of Stars in One System

The four stars and one planet of the 30 Ari system are illustrated in this diagram. This quadruple star system consists of two pairs of stars: 30 Ari B and 30 Ari A. A gas giant planet (red) orbits one of the stars in 30 Ari B about once a year. New observations led by NASA's Jet Propulsion Laboratory in Pasadena, California, identified the fourth star in the system (green); the three others stars and the planet were previously known. This is the second quadruple star system known to host a planet.

The orbits shown are only approximations and are not as circular as they appear. Distances are not drawn to scale.

Image credit: NASA/JPL-Caltech

Page Last Updated: March 4th, 2015
Page Editor: Tony Greicius