It is one of the largest exoplanets ever found.
Astronomer shave discovered a supermassive planet–estimated at around three times the mass of Jupiter–orbiting a distant star.
A monstrous planet three times the mass of Jupiter has been discovered in a distant planetary system located approximately 1,242 light-years away. Called Kepler-88 d, it orbits its star every four years. Astronomical observations of the gigantic exoplanet have revealed its has al elliptical orbit around its host star. Kepler-88 is a distant star-like sun in the constellation Lyra. It has an apparent magnitude of 13.5.
The discovery is the result of six years of data taken with the Echelle high-resolution spectrometer (HIRES) instrument at the Keck I 10-meter telescope in Hawaii. The system, Kepler-88, was already famous among astronomers for two planets that orbit much closer to the star, Kepler-88b, and c (the planets are usually named alphabetically in the order of their discovery).
Those two exoplanets have a strange and surprising dynamic called medium motion resonance. Neptune-sized planet b orbits the star in just 11 days, which is almost exactly half of the 22-day orbital period of planet c, a planet of similar mass to our solar system’s Jupiter. The mechanical nature of their orbits is energy efficient, like a parent pushing a child on a swing. Every two turns planet b goes around the star, it gets pumped.
The outer planet, Kepler-88 c, is twenty times more massive than planet b, so its force produces dramatic changes in the orbital timing of the inner planet. Astronomers observed these changes, called transit time variations, with NASA’s Kepler Space Telescope, which detected the precise times when Kepler-88 b crossed (or transited) between the star and the telescope, from our observational period.
Although variations in transit time (TTV for short) have been detected in a few dozen planetary systems, Kepler-88 b has some of the largest time variations. With transits arriving up to half a day early or late, the system is known as “the King of TTVs.”
The newly discovered exoplanet adds another dimension to astronomers’ understanding of distant solar system.
“At three times the mass of Jupiter, Kepler-88 d has likely been even more influential in the history of the Kepler-88 system than the so-called King, Kepler-88 c, which is only one Jupiter mass,” says Dr. Lauren Weiss, Beatrice Watson Parrent Postdoctoral Fellow at UH IfA and lead author on the discovery team. “So maybe Kepler-88 d is the new supreme monarch of this planetary empire – the empress.”
Perhaps these massive distant exoplanets had as much influence as Jupiter in our solar system. Such distant worlds could have helped with the development of rocky planets and directed aquifer comets toward them, which in turn may have helped the distant worlds acquire water.
Weiss and colleagues are searching for similar real planets in other planetary systems with small planets. The study describing the discovery of Kepler-88 d is published in the April 29 issue of the Astronomical Journal.
