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 · 11 citations
Physics and Astronomy · #Stellar, planetary, and galactic studies #Astrophysics and Star Formation Studies #Astro and Planetary Science

paper · pdf · doi:10.1126/science.adn6088

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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• Formation of Free-Floating Planets via Ejection: Population Synthesis with a Realistic IMF and Comparison to Microlensing Observations
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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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