Astronomers have discovered a hot-Jupiter exoplanet so close to its host star, called NGTS-10, that a year on that planet lasts only 18.4 hours, making it the shortest-period hot Jupiter ever found.
An artist’s impression of the hot-Jupiter exoplanet NGTS-10b and its host star. Image credit: Sci-News.com.
NGTS-10 is a K5-type main-sequence star located approximately 1,060 light-years from Earth.
The star is about 10 billion years old, moderately active, and has an effective temperature of 7,461 degrees Fahrenheit (4,127 degrees Celsius).
The newly-discovered planet is a so-called ‘hot Jupiter,’ a Jupiter-like exoplanet orbiting very close to its star.
Named NGTS-10b, the alien world is 1.2 times larger than Jupiter and 2.2 times more massive.
It orbits NGTS-10 with a period of only 18.4 hours (0.767 days), making it the shortest period hot Jupiter yet discovered.
“NGTS-10b orbits its host star at only 4.4 stellar radii,” said University of Warwick astronomer James McCormac and his colleagues from the United Kingdom, Australia, Germany, Chile, and the United States.
“However, as the stellar effective temperature is lower than other ultra-short period hot Jupiter host stars, the level of insolation is also reduced.”
“Therefore, while the period is the shortest yet discovered, the received radiation is significantly less than that of planets such as WASP-18b or WASP-19b.”
NGTS-10b was discovered using the Next Generation Transit Survey (NGTS), an array of twelve 20-cm telescopes at Paranal Observatory in Chile.
Dr. McCormac and co-authors analyzed data collected by a single NGTS camera between September 21, 2015 and May 14, 2016.
“NGTS-10b joins a short list of ultra-short period Jupiters that are prime candidates for the study of star-planet tidal interactions,” they said.
A paper detailing the discovery will be published in the Monthly Notices of the Royal Astronomical Society.
_____
James McCormac et al. 2019. NGTS-10b: The shortest period hot Jupiter yet discovered. MNRAS, in press; arXiv: 1909.12424
