Exoplanet Microlensing
Two microlensing planets arrive with unequal certainty
One high-magnification event yields a tightly measured 41-Earth-mass planet; the other remains strongly dependent on priors despite a Euclid detection.
Briefed October 8, 2026 · Aliens in the Clouds
Preprint · Two Planetary Solutions
Kansuke Nunota and collaborators analyze the high-magnification events KMT-2021-BLG-0247 and MOA-2023-BLG-169. For the first event, finite-source and microlens-parallax effects constrain a roughly 0.9-solar-mass host 6.7 kiloparsecs away and a planet of 41 plus or minus 5 Earth masses at a projected separation near three astronomical units.
The second event's source is extraordinarily faint, leaving a broad family of correlated light-curve solutions. Euclid imaging detects blended light at the event position and improves the estimate to a roughly 0.48-solar-mass host and a planet near 143 Earth masses, but with much wider uncertainties. The comparison makes the evidence hierarchy visible: two planet interpretations can be reasonable while only one is tightly pinned down by the available observables.
Why it matters
Microlensing reaches cold planets thousands of parsecs away, but its brief alignments do not all carry the same information. Publishing the uncertainty structure is part of the discovery.
What the source establishes
Fresh AAS-journal submission posted October 7. The KMT system is unusually well constrained; the MOA system remains sensitive to Galactic priors and how Euclid's blended flux is interpreted.
Published by Aliens in the Clouds. These AI-assisted summaries link to their sources and distinguish reported claims from established findings. Skinny Ed is a fictional mascot; High Thoughts are comedy. Send a correction with its source.