Researchers discover incredibly rare triple star system

According to a newly-published study, a rare triple-star system containing a planet in a stable orbit was recently discovered by researchers at the Harvard-Smithsonian Center for Astrophysics.

Published in the Astronomical Journal, the study detailed the discovery of distant world, known as KELT-4Ab.

While the planet orbits one star in the system, that star is circled by a pair of stars. Standing on the surface of the KELT-4Ab, the two orbiting stars would appear as bright as the full moon does in our sky.

In addition to describing an exotic solar system, the study also provides new details on the evolution of a “hot Jupiter,” or a gas giant that orbits close to its host star.

KELT-4Ab, which is approximately the same size as Jupiter, orbits KELT-A once every three days. The nearby stars KELT-B and KELT-C orbit each other once every three decades, and jointly they travel around KELT-A and its planet about every 4,000 years.


Rare star systems

Three-star systems are extremely rare, and yet last year, a team of astronomers announced the discovery in mid-formation.

In a gas cloud about 800 light-years from Earth, researchers spotted a core of gas that they predict will condense into a three-star system about 40,000 years.

Using the Very Large Array radio observatory in New Mexico, the Green Bank Telescope in West Virginia and the James Clerk Maxwell Telescope in Hawaii, the study team was able to map methane molecules in a thick core of gas called Barnard 5 (B5) in an area of the constellation Perseus. In their observations, the team saw filaments of gas in B5 becoming fragmented. These fragments are beginning to form stars, and will eventually form a three-star system, the study said.

The study added fragmentation of gas filaments to the list of theories on star formation, which includes fragmentation of a primary gas core, fragmentation inside of a disk of material around a young star and gravitational entrapment.

According to the study, B5 will generate stars from one-tenth to over one-third the mass of our Sun. The distances between stars will probably range from 3,000 to 11,000 astronomical units (AU), or the distance between the Earth and the Sun, the study said.


Image credit: NASA JPL