web analytics

A Newly Discovered Planet Is Reared by Four Parent Stars

4 star planet

Image credit: Artist interpretation of 30 Ari. Credit: Karen Teramura, UH IfA

Compared with Earth with only one parent star, other planets existing in systems are quite different. It is common to see more binary star systems than single stars, and it is much rarer to come across planets in triple star systems. But recently researchers have traced a planet in a quadruple star system, which is just the second one to be found so far. This latest discovery was based on observations from the Palomar Observatory in California and released in the newest edition of the Astronomical Journal.

Being regarded as a “hot Jupiter,” the planet in the constellation Aries has been named 30 Ari, which is 136 light years away from Earth. Since its location is very close to its primary star, it is not habitable. The planet can complete one orbit in just three Earth days.

As co-author Andrei Tokovinin from the Cerro Tololo Inter-American Observatory said, nearly four percent of solar-type stars were in quadruple systems and that figure was bigger than previous estimates thanks to much improved observational techniques.

Although there are some quadruple star systems existing in the galaxy, 30 Ari is the second exoplanet in such a system to be identified after the discovery of KIC 4862625 in 2013, which is 5,000 light years away from our Earth.

The discovery of 30 Ari was made by observations from NASA’s Kepler Space Telescope. Researchers hoped that they could discover more planets in unconventional systems so as to deepen human understanding about the way in which planets take shape under the different conditions.

According to lead author Lewis Roberts of Jet Propulsion Laboratory, star systems could form in various, from single stars and binary stars to triple stars, even in rare case quintuple star systems. It was fascinating to see how nature puts these things together.

But this system seems quite weird, because the stars in the system are very distant from one another. The distance between the primary and secondary stars is 44,000 astronomical units (AU) and one AU is the average distance from the Earth to the sun. The third star in the system is 28 AU away from the primary. The fourth star is 23 AU, which is the closest one to the primary.

Although it appears counterintuitive, the fourth—and closest—star is not thought to have played an active role in the formation of 30 Ari, but the complex gravitational pull from the other three are regarded to have an impact on the planet’s size.

In his conclusion, Roberts confirmed that such result would deepen the connection between multiple star systems as well as massive planets.

Jource: NASA