A Super-Earth exoplanet, located approximately 14,000 light-years from Earth, has been discovered using Korea Microlensing Telescope Network (KMTNet). Super-Earths are rocky planets like Earth, but can have up to ten times our planet’s mass.
This newly discovered planet has a mass about 1.3 times that of Earth, making it the smallest long-period super-Earth found to date.
On Friday, the Korea Aerospace Administration (KASA) announced that an international research team, including the Korea Astronomy and Space Science Institute (KASI), discovered the long-period Super-Earth exoplanet OGLE-2016-BLG-0007Lb using KMTNet. Exoplanets are planets that orbit stars other than our Sun.
The planet orbits its host star at a distance of about 1.5 billion kilometers (932 million miles). The star has a mass 0.6 times that of our Sun. This makes it the most distant planet from its host star discovered, with an orbit beyond Saturn’s in our solar system – about ten times the Earth-Sun distance.
The planet’s orbital period is estimated to be around 40 years.
Using KMTNet, the research team identified numerous long-period super-Earths that were challenging to detect with existing observation systems. This allowed them to build a sample encompassing terrestrial planets (rock-like) and Jovian planets (gas-like).
Notably, by analyzing statistics from 63 exoplanets discovered between 2016 and 2019, it has been confirmed a bimodal distribution in planet frequency, corresponding to terrestrial and Jovian planets. This distribution appears as two distinct peaks in the continuous probability distribution curve.
Statistically, for every 100 host stars, there would be approximately 35 Super-Earths and 12 Jovian planets.
This data supports the theory that terrestrial and Jovian planets form through different processes.
It also indicates terrestrial planets are more common among long-period exoplanets than Jovian planets. Previous research had predicted this, but observations had mainly revealed Jovian planets, creating a discrepancy between theory and observation.
Various methods for observing exoplanets have been developed, each revealing different planetary characteristics. These methods are used complementarily.
KMTNet, developed and operated by KASI, uses the microlensing method and specializes in discovering long-period exoplanets. About 300 exoplanets have been discovered using microlensing techniques in academia, with KMTNet directly identifying 227 of these since its operation began.
Jung Yeon Kil, a senior researcher from KASI, emphasized that observing exoplanets provides crucial insights into planetary formation and evolution.
Korea Astronomy and Space Administration (KASA) Administrator Yoon Youngbin emphasized that South Korea is leading in exoplanet discovery thanks to the exceptional capabilities of the KMTNet system. He conveyed optimism about further scientific breakthroughs using this equipment.
The study was published in the prestigious journal Science. The research team plans to secure more exoplanet samples using KMTNet and continue with more precise observations and analyses based on these findings.