Astronomers have found a brand new exoplanet orbiting the close by Okay-dwarf star HD 137010 after detecting a single, shallow transit within the archival knowledge from NASA’s Kepler prolonged K2 mission.
HD 137010b is estimated to be solely 6% bigger than Earth, with a floor temperature extra much like Mars — probably beneath minus 70 levels Celsius. Picture credit score: NASA / JPL-Caltech / Keith Miller, Caltech & IPAC.
HD 137010 is a K3.5V dwarf star situated about 146 light-years away within the constellation of Libra.
Its age is estimated to lie between about 4.8 and 10 billion years, and its low degree of magnetic exercise is according to an previous, comparatively quiet star.
Also referred to as BD-19 4097, HIC 75398, 2MASS J15242123-1944215 or TYC 6179-1111-1, the star has a visible magnitude of 10.1, making it one of many brightest stars recognized to host an Earth-sized planet with temperate orbital properties.
Designated HD 137010b, the newly-discovered planet was detected throughout K2 Marketing campaign 15, when NASA’s Kepler house telescope noticed the father or mother star for practically three months in 2017.
“Earlier discoveries of Earth-sized planets in liveable zones are principally round so-called crimson dwarfs, that are a lot smaller and dimmer than our Solar,” said College of Southern Queensland astronomer Alexander Venner, first creator of the examine.
“Scientists have considerations that these planets may lose their complete atmospheres as a result of high-energy radiation from their host stars, leaving them uninhabitable to recognized life.”
“In distinction, the host star of HD 137010b has properties a lot nearer to our Solar, which makes it extra possible that the planet may maintain an environment based mostly on present theoretical fashions.”
Within the examine, Dr. Venner and colleagues examined K2 knowledge, close by stellar gentle curves, archival imaging, radial velocity measurements, and astrometric knowledge to evaluate the character of the sign, which lasted about 10 hours.
The checks strongly point out that the transit occurred on the goal star and is astrophysical in origin, reasonably than being brought on by background contamination, a close-by eclipsing binary, or a photo voltaic system object.
From the transit depth, the astronomers derived a planetary radius of about 1.06 instances that of Earth.
Primarily based on the transit period and stellar properties, they estimate an orbital interval of roughly 355 days.
At this distance from the host star, HD 137010b is estimated to obtain roughly 29% of the stellar flux obtained by Earth from the Solar, inserting it close to the outer fringe of the star’s liveable zone.
“If HD 137010b has an environment like that of Earth or Mars, it’s prone to be colder than Antarctica,” Dr. Venner mentioned.
“However a thicker ambiance may heat the planet sufficient to permit liquid water, which may be a great atmosphere for all times.”
“Whereas present generations of astronomical devices can not absolutely characterize this newly-discovered planet, it may turn into a chief goal for future radial velocity devices aiming to detect Earth analogues.”
“Future house missions designed to straight picture Earth-like planets, just like the NASA Liveable Worlds Observatory, may additionally be able to capturing photos of HD 137010b.”
The invention is reported in a paper within the Astrophysical Journal Letters.
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Alexander Venner et al. 2026. A Cool Earth-sized Planet Candidate Transiting a Tenth Magnitude Okay-dwarf from K2. ApJL 997, L38; doi: 10.3847/2041-8213/adf06f
