Astronomers have discovered a third exoplanet in the Kepler-47 system, which makes the already mind-boggling star system even more interesting.
The newly found planet in the Kepler-47 system has been dubbed Kepler-47d, is up to seven times more massive than Earth
Using data from NASA’s Kepler Space Telescope, researchers spotted the new exoplanet orbiting between two previously discovered planets, Kepler-47b and Kepler-47c.
“We certainly didn’t expect it to be the largest planet in the system,” revealed William Welsh, an astronomer at San SDSU and co-author in the press release.
“This was almost shocking.”
Some seven years ago, back in 2012, Welsh and his team discovered two of the planets, Kepler-47b and Kepler-47c, circling the two stars.
Both these exoplanets have two suns in their skies, similar to the planet Tatooine, Luke Skywalker’s homeworld in the Star Wars movies saga.
Both worlds were detected by astronomers using the “transit method.”
#SDSU astronomers have discovered a third planet in the Kepler-47 system, securing the system’s title as the most interesting of the binary-star worlds. See details of their research ➡️ https://t.co/IOiNmgxSZ8
Video courtesy: NASA/JPL‑Caltech/T. Pyle pic.twitter.com/yNwzHxmWZp
— San Diego State University (@SDSU) April 16, 2019
With its three planets orbiting two suns, Kepler-47 is the only known multi-planet circumbinary system. Circumbinary planets are those that orbit two stars.
“We saw a hint of a third planet back in 2012, but with only one transit we needed more data to be sure,” said SDSU astronomer Jerome Orosz, the paper’s lead author.
“With an additional transit, the planet’s orbital period could be determined, and we were then able to uncover more transits that were hidden in the noise in the earlier data.”
As noted by Space.com, the Kepler-47 star system is not a young one. In fact, astronomers estimate the star system is about 3.5 billion-years-old. It’s located around 3,340 light-years from Earth.
“This work builds on one of the Kepler’s most interesting discoveries: that systems of closely-packed, low-density planets are extremely common in our galaxy,” added Jonathan Fortney, a UC Santa Cruz astronomer who was not involved in the study.
“Kepler-47 shows that whatever process forms these planets — an outcome that did not happen in our solar system — is common to single-star and circumbinary planetary systems.”
Thanks to the discovery of the new planet, astronomers will have a much better understanding of the circumbinary system.
As noted by SDSU astronomers, the inner, middle and outer planets of the Kepler-47 system are 3.1, 7.0, and 4.7 times the size of the Earth, and take 49, 187, and 303 days, respectively, to orbit around their suns.