Scientists have discovered a hot Saturn-like planet orbiting a star in another solar system 700 light-years from Earth.
Researchers, led by University of Louisville doctoral student Karen Collins, discovered exoplanet KELT-6b using the Kilodegree Extremely Little Telescope (KELT) and other ground-based tools.
Astronomers caught sight of the planet when it passed in front of, or “transited,” its host star — and they have since discovered that the planet resembles one of the most famous and well-studied transiting planets, HD 209458b.
As seen from Earth, KELT-6b resides in the constellation Coma Berenices, near Leo, and has an orbit that transits its star every 7.8 days. That means a “year” on the planet lasts just over a week, and its trip across the face of its star, as seen from Earth, lasts only five hours.
Collins and her team determined that KELT-6b is a hot gas-giant planet orbiting a star about the same age as our Sun. The planet resembles our own Saturn in terms of size and mass, though it has no rings.
It also resembles the most studied exoplanet to date, HD 209458b, but differs because it was formed in an environment low in metals — that is, elements heavier than hydrogen and helium.
“KELT-6b is a ‘metal-poor’ cousin of HD 209458b,” said Keivan Stassun, Vanderbilt astronomy Professor and member of the KELT team.
“The role of metals in the stellar environments in which planets form is a major question in our understanding of these other worlds.
“This new planet is among the least endowed with such metals that we know of, and because it is so bright it should serve as a benchmark for comparative studies of how and under what conditions planets form,” Stassun said.
Collins is now working to confirm and characterise a second body in the same system as KELT-6b.
The findings were announced at the American Astronomical Society’s meeting in Indianapolis.