List of exoplanets detected by microlensing
Exoplanets Detected by Microlensing: A Short, Easy-to-Understand Overview
What microlensing is
Gravitational microlensing detects planets by watching how a foreground star’s gravity momentarily magnifies a more distant background star. If the foreground star has a planet, it can distort the magnification in a telltale way. By studying these light changes, scientists can estimate a planet’s mass and how far it sits from its star. This method is especially good at finding planets that are far away, near the so-called snow line, and even very low-mass worlds.
What the microlensing list tells us (in short)
- Smallest planets found this way: Planets with masses around Earth’s mass have been detected. A notable example is KMT-2020-BLG-0414Lb, with a mass about 0.96 Earth masses, and OGLE-2016-BLG-0007Lb, around 1.3 Earth masses. This shows microlensing can reach Earth-like masses.
- Wide versus close distances: The largest planet-star separation found by microlensing is about 15 AU (OGLE-2008-BLG-092Lb). The closest confirmed separation is around 0.12 AU (KMT-2020-BLG-0414Lc). This highlights microlensing’s ability to probe a wide range of distances.
- Multi-planet systems: There are seven known systems detected by microlensing that host two planets each.
- What microlensing is good for: It can detect planets around faint or distant stars, including low-mass stars, brown dwarfs, and objects in the Galactic bulge or disk. It’s also one of the few methods that can spot planets far from their stars or even rogue (unbound) planetary-mass objects.
A few representative examples (highlights from the long list)
- OGLE-2003-BLG-235Lb: One of the early microlensing discoveries, showing the method’s potential.
- OGLE-2006-BLG-109Lb and OGLE-2006-BLG-109Lc: Early multi-planet detections in a single system.
- KMT-2020-BLG-0414L b: One of the smallest-mass planets found by microlensing (about Earth mass).
- OGLE-2008-BLG-092Lb: The widest-known separation in microlensing detections (about 15 AU).
- MOA and KMTNet surveys have produced many additional detections, including some that involve the planet candidates in binary or multiple-star settings and others that help measure planetary masses with parallax and lens-flux techniques.
Candidate rogue planets
Several microlensing events have produced candidate rogue (free-floating) planets—worlds not bound to a star. Examples include:
- MOA-2011-BLG-274L (about 0.8 Jupiter masses, as a planetary-mass rogue candidate)
- OGLE-2011-BLG-322Lb (a potential second-generation microlensing planet)
- MOA-2011-BLG-262Lb and others, varying in mass from Earth-like to gas-giant scales
Note: Rogue planet detections via microlensing are challenging to confirm as rogue planets, since microlensing relies on a single, chance alignment.
Why microlensing discoveries matter
- Sensitivity to many planet types: This method is capable of finding planets at several astronomical units from their hosts, including Earth-mass and Neptune-mass worlds, which are harder to detect with other methods at great distances.
- Probing distant parts of the Galaxy: Microlensing can detect planets around stars in the Galactic bulge and outer disk, expanding our view beyond nearby stars.
- Complementary to other methods: Each detection method (radial velocity, transits, direct imaging, microlensing) samples different parts of the planet population. Together, they build a fuller picture of how planetary systems form and evolve.
Where to learn more
For a detailed catalog with names, masses, projected separations, and discovery years, you can consult major exoplanet databases such as NASA Exoplanet Archive or the Exoplanet.eu catalog, which compile microlensing discoveries and other exoplanet data. These resources keep updating as new microlensing events are analyzed and published.
In short
Microlensing has revealed a diverse set of planets—down to Earth-mass worlds and up to distant, widely separated giants—often around faint or distant stars. It also finds planets in unique settings, such as in binary systems or as possible free-floating “rogues.” The microlensing list continues to grow, offering a valuable view of planetary populations across the Milky Way.
This page was last edited on 1 February 2026, at 23:17 (CET).