The more than 4,300 confirmed exoplanets discovered to date share one thing in common – their relatively close orbit to the host star.
Now, astronomers have discovered something extraordinary – a giant exoplanet in a bizarre, 15,000-year orbit around a binary star. This is the first time that scientists have been able to classify such a large orbit.
The Exoplanet is called HD 106906b, which is 11 times the mass of Jupiter. It orbits a pair of hot, main-sequence yellow-white stars called HD 106906; These stars are just 15 million years old and orbit each other in just 100 days. The entire system is 336 light years away.
Although this location is very different from our own solar system as a whole, the massive orbit of the HD 106906b is reminiscent of an elusive object, which astronomers believe will be closer to home – hypothetical, very broad-orbit Planet Nine.
“This system makes a unique comparison with our solar system,” said Meiji Nuyen, an astronomer at the University of California, Berkeley.
“It’s like a prediction for Planet Nine, separated from its host stars by a strange and very poorly designed orbit. [raises] The question of how these planets formed and ended up in their current configuration. “
The reason why most of the spacecraft we find are relatively close to their stars is very simple, and is generally related to how it detects and stabilizes exoplanets.
Two methods are most commonly used – the mode of transport, where telescopes look for dim tips in the light of a star because an orbital exoplanet passes in front of it, which is called transport; And in the oscillation mode, very small changes in the wavelengths of light of a star are pulled by the gravitational force of the exoplanet.
For both of these modes, Starlight can have either a dip or a stagger; Usually astronomers prefer certain tips or oscillations at certain intervals to stabilize an exoplanet.
So you can see why it can be hard to confirm something in a big orbit; For example, Jupiter is in orbit for 12 years. So you have to keep looking at the sky for a while.
(NASA, ESA, M. Nuen / UC Berkeley, R. de Rosa / ESO, and P. Kalas / UC Berkeley / Chetty)
But the HD 106906b, first discovered in 2013, is a rare beast: an exoplanet that was filmed live. Most of the time exoplanets are very dizzy and very close to their host star, but the distance of the HD 106906b means that it does not disappear in the brightest brightness of its binary stars.
Still, working in the orbit of Exoplanet is not easy. For that, the team of researchers needed data from the Hubble Space Telescope. Going back 14 years into the archives, the HD 106906b was able to retrieve additional data from its stars at a distance of 737 astronomical units at a slower rate.
As you might think, an Exoplanet in 15,000-year orbit would not seem to move much in 14 years, but astronomers had enough to connect the orbit together.
The 15,000-year orbit period is only part of what they learned. Another, more confusing area is that the exoplanet has a high orbital slope – the angle at which the debris of objects around two stars is pronounced to disk.
“To highlight why this is different, we can look at our own solar system and see that the planets are all in the same plane,” Queen said.
“It would be strange if Jupiter tilted 30 degrees compared to other planets orbiting. This raises all sorts of questions about how the HD 106906b ended up in such a sloping orbit so far.”
One possibility is that the HD 106906b does not orbit binary stars. In this scenario, the Exoplanet would have been a rudder, wandering aimlessly until it was large enough to be caught in orbit for a star (or binary).
Another scenario – and one where the panel is tilted – was created by HD 106906b on the binary trash disk. Initially, the orbit of the exoplanet is deflected toward the star if the disk is pulled. There, in a close orbit, the gravitational interactions between the two stars may have kicked the Exoplanet into a very distant, highly inclined orbit, which was confirmed by the passing star.
Both scenarios lead to an odd, bizarre orbit, which creates the irregularity found in the debris disk in binary orbit.
“It’s like coming to the scene of a car accident. You’re trying to rebuild what happened,” U.C. said. Said Berkeley astronomer Paul Glass.
“Does it pass through the stars that disturbed the planet, and then the planet interferes with the disk? Did the binary in the middle disturb the planet first, and then it interfered with the disk? Or did the passing stars disturb both the planet and the disk at the same time? This is astronomical detection, here We’ll gather some credible storylines about what happened. “
Both scenarios have been proposed for Planet Nine (although in the case of Planet Nine, Jupiter kicked in), an imaginary solar system planet is predicted to be 5 to 10 times the mass of Earth, with the Sun in an orbit of 300 to 700 astronomical units.
There is significant doubt as to the existence of Planet Nine, but HD 106906b not only shows that such a strange orbit is possible, but also that it may occur relatively early in the lifespan of a planetary system.
But there is still a lot of work to be done on the HD 106906B.
“There are still a lot of open questions about this system,” said Robert de Rosa, an astronomer at the European Southern Laboratory in Chile.
“Unraveling many of the mysteries of this remarkable planetary system, both observers and theorists will be reading HD 106906 in the years to come.”
Research has been published Astronomy Magazine.