Star Wars-like Planetary System Verified as Most Interesting of Binary-Star Worlds
A team of astronomers, including Nader Haghighipour from the Institute for Astronomy at the University of Hawaiʻi at Mānoa, have discovered a third planet in the circumbinary planetary system Kepler-47.
This discovery cements the system’s title as the most interesting of the binary-star worlds, and marks the first complete and dynamically full planetary system around a binary star. A complete and dynamically full planetary system is one that cannot have any more planets — like our solar system. Circumbinary planets are those that orbit both stars of a binary star system, like Tatooine in the Star Wars films.
Animation showing the orbits of the three planets in the Kepler 47 system.
Credit: NASA/JPL-Caltech/T. Pyle
The planets in the Kepler-47 system were detected via the transit method. This method relies on small decreases in the measured brightness of a star (or, in this case, a pair of stars), when a planet passes in front of the star as seen from Earth. The newly discovered planet, dubbed Kepler-47d, was not detected earlier because its distance from its host stars means it produces only a tiny transit signal.
“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.”
Artist’s depiction of the relative sizes of the three planets in the Kepler-47 system. The large middle planet is the newly discovered planet, Kepler-47d.
Credit: NASA/JPL-Caltech/T. Pyle
“In 2015, we predicted the existence of a third planet in this system on dynamical grounds. It is great to see reality matches our prediction,” said Haghighipour.
The inner, middle, and outer planets of 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 the central binary. The stars themselves orbit each other in only 7.45 days. One star is similar to the Sun, while the other has only one-third of the Sun’s mass. The researchers were surprised by both the size and location of the new planet. Kepler-47d is the largest of the three planets in the Kepler-47 system.
An overhead view of the orbital configuration of the Kepler-47 circumbinary planet system.
The Kepler-47 planetary system is an example of the diversity of solar systems outside our own. Despite having two “suns”, the entire system is so compact that it would fit inside the orbit of Earth. It is approximately 3340 light-years away in the direction of the constellation Cygnus.
“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,” said University of California, Santa Cruz astronomer, Jonathan Fortney, who was not part of the study.
This research has been published in the Astronomical Journal, volume 157, issue 5, article 174, doi: 10.3847/1538-3881/ab0ca0.
Contacts and sources:
Dr. Nader Haghighipour
UH Institute for Astronomy
APeX - Far superior to colloidal silver in destroying viruses, bacteria and other pathogens.
Ultimate Curcumin - Natural pain relief, reduce inflammation and so much more.
Supreme Fulvic - Nature's most important supplement! Vivid Dreams again! See Testimonials
MitoCopper - First bioavailable copper destroys pathogens and gives you more energy.
Prodovite - The Secret To Healing is in the Blood! Complete absorption in 5 minutes.