Korean Team Discovers Smallest Long-Period Super-Earth
- Yul So
- May 7
- 2 min read
Updated: May 9
May 7, 2025
Yul So
An international research team, led by the Korea Astronomy and Space Science Institute (KASI), has discovered the smallest long-period super-Earth ever detected. Their findings were published in the prestigious journal Science on April 25.
Using the Korea Microlensing Telescope Network (KMTNet), a system of three telescopes located in Australia, South Africa, and Chile, the researchers identified the exoplanet "OGLE-2016-BLG-0007Lb." This planet, about 1.3 times the mass of Earth, is located roughly 14,000 light-years away and orbits a host star with about 60% the mass of the Sun. Its orbital distance is about 1.5 billion kilometers, nearly ten times the distance between Earth and the Sun — with an estimated orbital period of around 40 years.
The group employed a method known as gravitational microlensing, in which a star's (and its planets') gravitational field magnifies the light of a background star by acting as a lens. Noticeable variations in the lensing light curve indicate the existence of a planet.
Beyond this discovery, the researchers analyzed 63 exoplanets detected between 2016 and 2019 using KMTNet data. They discovered a bimodal distribution of planet masses, suggesting that super-Earths and gas giants resembling Jupiter are the two main populations. According to statistics, there were roughly 35 super-Earths and 12 gas giants for every 100 planets.
These results raise the possibility that long-period rocky planets are more prevalent than previously believed and provide credence to the idea that rocky and gas planets develop through different processes.
But as the outdated KMTNet system struggles to function because of a lack of financing, worries are mounting. Researchers are optimistic that KMTNet will complement NASA's forthcoming Nancy Grace Roman Space Telescope, which is scheduled to launch in 2027, to further the hunt for far-off exoplanets.
