Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits

2025/04/24 by Weicheng Zang, Youn Kil Jung, Jennifer C. Yee +88 · 2 voices · 33 citations
Physics and Astronomy · #Astro and Planetary Science #Astrobiology #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Exoplanet #Galaxy #Gas giant #Gravitational microlensing #Jupiter (rocket family) #Mass distribution #Orbit (dynamics) #Physics #Planet #Planetary system #Stars #Stellar, planetary, and galactic studies

paper · pdf · doi:10.1126/science.adn6088

published in Science 388(6745), 400-404 (American Association for the Advancement of Science)

openalex publication_date 2025/04/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06

Abstract

Exoplanets classified as super-Earths are commonly observed on short-period orbits, close to their host stars, but their abundance on wider orbits is poorly constrained. Gravitational microlensing is sensitive to exoplanets on wide orbits. We observed the microlensing event OGLE-2016-BLG-0007, which indicates an exoplanet with a planet-to-star mass ratio roughly double the Earth-Sun mass ratio, on an orbit longer than Saturn's. We combined this event with a larger sample from a microlensing survey to determine the distribution of mass ratios for planets on wide orbits. We infer that there are ~0.35 super-Earth planets per star on Jupiter-like orbits. The observations are most consistent with a bimodal distribution, with separate peaks for super-Earths and gas giants. We suggest that this reflects differences in their formation processes.

Citations

• emcee: The MCMC Hammer
• JHKLM photometry - Standard systems, passbands, and intrinsic colors

Cited by

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• Are We There Yet? Challenges in Quantifying the Frequency of Earth Analogs in the Habitable Zone
• Formation of Free-Floating Planets via Ejection: Population Synthesis with a Realistic IMF and Comparison to Microlensing Observations
• Predictions of the Nancy Grace Roman Space Telescope Galactic Exoplanet Survey. IV. Lens Mass and Distance Measurements
• Binary-lens Microlensing Degeneracy: Impact on Planetary Sensitivity and Mass-ratio Function
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• The Variable Sky Through the OGLE Eye
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• Planetesimal Scattering Efficiency of Cold Giant Planet Architectures
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Discussions

• Microlensing data from KMTNet suggests that rocky super-Earth planets are common far from their star, in orbits like Jupiter: arxiv.org/abs/2504.20158 In fact, there would be 0.35 'distant Earths' per [bsky, 25 points, 0 comments]
• Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits: arxiv.org/abs/2504.20158 -> Astronomers Find Far-flung “Super Earths” Are Not Farfetched: cfa.harvard.edu/ne [bsky, 2 points, 0 comments]

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