Most eccentric planet ever known flashes astronomers with reflected light

Source: Phys.org

Most eccentric planet ever known flashes astronomers with reflected light

March 18, 2016

Led by San Francisco State University astronomer Stephen Kane, a team of researchers has spotted an extrasolar planet about 117 light-years from earth that boasts the most eccentric orbit yet seen.

What's more, Kane and his colleagues were able to detect a signal of reflected light from the planet known as HD 20782—a "flash" of starlight bouncing off the eccentric planet's atmosphere as it made its closest orbital approach to its star. The discovery was announced online Feb. 28, 2016 in The Astrophysical Journal.

In this case, "eccentric" doesn't refer to a state of mind, but instead describes how elliptical a planet's orbit is around its star. While the planets in our solar system have nearly circular orbits, astronomers have discovered several extrasolar planets with highly elliptical or eccentric orbits.

HD 20782 has the most eccentric orbit known, measured at an eccentricity of .96. This means that the planet moves in a nearly flattened ellipse, traveling a long path far from its star and then making a fast and furious slingshot around the star at its closest approach.

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Read more: http://phys.org/news/2016-03-eccentric-planet-astronomers.html



An artist's rendering shows the planet HD 20782, the most eccentric planet ever known, passing its star in close orbit. Credit: NASA