Astronomers Discover Exoplanet With Most Eccentric Orbit

Posted: Mar 20 2016, 10:04am CDT | by , Updated: Mar 20 2016, 10:54pm CDT, in News | Latest Science News


Astronomers Discover Exoplanet with Most Eccentric Orbit
n artist's impression of the planet HD 20782, the most eccentric planet ever known, passing its star in close orbit.

Extrasolar planet HD 20782 has the most eccentric orbit ever seen. These types of exoplanets are not found in our solar system.

Astronomers have spotted an extrasolar planet that has a weird orbit, in fact, it is the most eccentric orbit ever observed. 

Most of the planets in our solar system such as Venus, Neptune and Earth have nearly circular orbits. A perfectly circular orbit has an eccentricity of zero. As the number gets higher, the eccentricity accelerates and indicates the amount by which an object around another body can deviates from a perfect circle. 

Researchers have discovered many exoplanets with highly eccentric or elliptical orbits before but the newfound exoplanet has the most eccentric orbit known. 

Exoplanet HD 20782 is about 117 light years away from Earth and has an eccentricity of 0.96, meaning that the planet moves in flattened eclipse as it travels a long path far from its star and then make a sudden slingshot around its host as it comes close to it. Researchers also detected a flash of light bouncing off the eccentric planet when it makes closest orbital approach to its star.

HD 20782 is a type of extraoslar planet that is not seen in our solar system. So, it provides astronomers a unique opportunity to study the structure and composition of a highly eccentric-orbit-planet, which comes too close its host star but manages to survive the blistering exposure. 

“When we see a planet like this that is in an eccentric orbit, it can be really hard to try and explain how it got that way,” said lead researcher Stephen Kane from San Francisco State University. “It’s kind of like looking at a murder scene, like those people who examine blood spatter patterns on the wall. You know something bad has happened, but you need to figure out what it was that caused it.”

The weird exoplanet HD 20782 completes an orbit around the star in 597 days. At the most distant point in the orbit, the planet is separated from its star by nearly three times (2.5) the distance between the Sun and Earth. But when it makes closest approach to its star, the planet is really close, a staggering 0.06 of the same Earth-sun distance. 

Researchers used a satellite based telescope to collect the light data as the planet orbits closest to its stars and used new parameters to measure its eccentricity.

The key here is to observe the change in brightness which appears to be the signal of a reflected light coming from the planet’s atmosphere. The close monitoring of this reflected light can reveal more about the composition and atmosphere of the planet.

Science theorizes if an icy, highly reflective planet comes too close to the Sun, the heat would strip the atmosphere of the planet and make it look dark but this is not the case with newly discovered exoplanet. 

“The atmosphere of the planet doesn’t have a chance to respond,” said Kane. “The time it takes to swing around the star is so quick that there isn’t the time to remove all the icy materials that make the atmosphere so reflective.”

Researchers have not been able to fully observe the atmosphere of the exoplanet so far but they suspect that its atmosphere resembles to that of Jupiter. The mass of the exoplanet is also similar to highly reflective cloud cover planet Jupiter. 

Researchers are currently looking at various theories to pinpoint why this planet is showing highly eccentric orbit. There could possibly be two planets in the system that came too close to each at a point. The collision or near-collision between them might have caused to eject one planet from the system entirely and pushed it on its eccentric path or it could be second star in a binary system that has threw HD 20782 off a more eccentric orbit.

You May Like


The Author

Hira Bashir covers daily affairs around the world.




Leave a Comment

Share this Story

Follow Us
Follow I4U News on Twitter
Follow I4U News on Facebook

Read the Latest from I4U News