Although our star system consists of planets and one star or sun, astronomers have discovered systems with a planet and two, three, or four stars. Finding such star systems is not surprising because binary stars are more common in our galaxy than single stars.
Using the Robo-AO and the PALM-3000 adaptive optics systems fitted to telescopes at the Palomar Observatory in San Diego, California, astronomers have discovered a planet in a quadruple star system.
This is only the second time a planet has been identified in a quadruple star system. While the planet in this system was seen before, it was thought to have three stars, not four. Citizen scientists using public data from NASA’s Kepler mission discovered the first four-star planet, KIC 486265, in 2013.
The finding suggests that there may be more planets in quadruple star systems than previously thought. The quadruple systems include two pairs of twin stars slowly circling each other at great distances. This configuration may be more common than believed.
The newly found four-star planetary system is called 30 Ari. It is located 136 light-years away in the constellation Aries. The planet is gaseous and enormous, 10 times the mass of Jupiter. It orbits around its primary star every 335 days. The primary star is partnered with a relatively close star that the planet does not orbit. These stars are locked in a long-distance orbit with another pair of stars about 1,670 astronomical units (or the distance between the Earth and sun) away. Astronomers believe that the planet and moons that might be orbiting it, could not sustain life.
If you were to stand on the surface of the planet, the four parent stars would appear as one small sun and two very bright stars that would be visible in daylight.
A system with one planet with three stars is a hot Jupiter that circles its primary star tightly, completing one orbit every three days. Astronomers already knew that the primary star of this system is locked in a gravitational tango with another star about 0.7 light years (or 44,000 astronomical units) away. That’s considered far apart for a pair of stellar companions. A third star has been discovered in the system that orbits the primary star from a distance of 28 astronomical units and is considered close enough to influence the development and final orbit of the hot Jupiter planet.
The Inter-University Center for Astronomy and Astrophysics in India and the California Institute of Technology in Pasadena, California developed the Robo-AO adaptive optics system and NASA’s Jet Propulsion Laboratory in Pasadena, while Caltech developed the PALM-3000 adaptive optics system used on the telescopes at the Palomar Observatory that discovered these star systems.