Super Earths Just 21 Lights Years Away

The planetary system, HD219134, contains three super-earths and one outer giant planet.

But HD219134b is exciting for another reason: it is the closest transiting planet known to scientists, and thus offers a rare opportunity for further study of its composition and atmosphere against the backdrop of its star. This super-Earth, titled HD 219134b was found to have a density very similar to that of our own planet.

Study lead author Ati Motalebi of the Geneva Observatory in Switzerland said she believes the planet is the ideal target for NASA’s James Webb Space Telescope in 2018. If the planetary system has the right alignment it can also transit-pass between us and the star and block some of the starlight-which will reveals the size of the planet.

“Transiting exoplanets are worth their weight in gold because they can be extensively characterized”, said Michael Werner, the project scientist for the Spitzer mission at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

During the transit, the light of the star crosses the atmosphere of the planet on its way to the observer, carrying over the spectral signature of the chemical species present in the atmosphere.

Furthermore, amid HD219134b’s fellow planets, the second furthest from the star weighs 2.7 times as much as Earth and orbits in 6.8 days, the next is 8.7 times more massive than Earth with a 47-day orbit.

The planet, thought to have a molten, rocky surface, moves around its star every three days.

Of these, the one that caught the attention of the research team is the one that transits, passing in front of the bright star.

‘Most of the known planets are hundreds of light-years away. “This one is practically a next-door neighbour”, said astronomer and study co-author Lars A. Buchhave of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. The mass of the planet obtained from the ground-based radial velocities, combined with the planet radius derived from space observations with Spitzer, yield the mean density of the planet.

HD219134b is 4.5 occasions extra large than the Earth and 1.6 occasions bigger, what planet hunters name an excellent-Earth.

Unfortunately, compared to the Kepler 452b, another recently discovered Earth-like planet, this new rocky planet’s star is way too close to sustain life.

The team also found that the two other inner planets are super-Earths.

It’s star, a 5th magnitude K dwarf, slightly colder and less massive than our Sun, is bright enough to follow with a naked eye from dark skies.

The astronomers said on Thursday that the planetary system consists of three super-Earths and a nearby dwarf star called HD 219134.

“This system, reminiscent of our own Solar System with the inner small planets and the outer gaseous one, will without doubt encounter a growing interest from the astronomical community”, the astronomers said.