Astronomers have just detected a strange triple star system where an exoplanet lies between three suns. The system, which is located 320 light years away within the Milky Way, has other surprises in store.
For instance, the lonely planet dubbed HD 131399Ab is not supposed to be located within the system in the first place, if we take into account astronomers’ calculations. Yet, the world is very real as direct imaging has recently shown.
A Strange Exoplanet
The strange planet which is located at the center of the triple star system is also on the verge of being ejected from the bizarre solar system, researchers noted. ,” Kevin Wagner, one of the scientists who discovered the system and astronomer at University of Arizona, explained that other similar planets located in solar systems with multiple stars are not located so close to their host stars as HD 131399Ab is.
Other exoplanets are usually located closer to one star, but the distance between them is still large enough for the stars’ influence on the planets to be insignificant. However, the newly found planet just sits a third of the way between its parent stars.
In short, the planet is so close to all of its three parent stars that at some point in its orbital path it can sense the gravitational tug of all three stars. Plus, being located a third of the way of a star makes the planet’s orbit highly unstable, so some scientists expect the star to leave the system at some point.
Scientists Divided over Orbital Stability
If that happens, HD 131399Ab will morph into a stray planetary mass object. However, Wagner’s team is confident that the star is somehow stable. Researchers explained that if the star was on an unstable orbit it should have departed by now.
Scientist estimate that the planet would have needed to complete just a few of its century-long orbits to leave the system for good if it were indeed unstable. And researchers think that the solar system is several million years old.
On the other hand, other researchers expect the system to become unstable since humans were able to track the planet in its orbital path for just one year. It is worth noting that HD 131399Ab needs 550 years to complete a full orbit.
A study on the strange star system was published July 7 in the journal Science.
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