Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits.
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| Title: | Microlensing events indicate that super-Earth exoplanets are common in Jupiter-like orbits. |
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| Authors: | Zang, Weicheng, Jung, Youn Kil, Yee, Jennifer C., Hwang, Kyu-Ha, Yang, Hongjing, Udalski, Andrzej, Sumi, Takahiro, Gould, Andrew, Mao, Shude, Albrow, Michael D., Chung, Sun-Ju, Han, Cheongho, Ryu, Yoon-Hyun, Shin, In-Gu, Shvartzvald, Yossi, Cha, Sang-Mok, Kim, Dong-Jin, Kim, Hyoun-Woo, Kim, Seung-Lee, Lee, Chung-Uk |
| Source: | Science. 4/25/2025, Vol. 388 Issue 6745, p400-404. 5p. |
| Subjects: | Extrasolar planets, Microlensing (Astrophysics), Jupiter's orbit, Saturn (Planet), Earth (Planet) |
| 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. Editor's summary: Gravitational microlensing occurs when a foreground star passes between Earth and a background star, focusing light and causing an apparent increase in brightness. If the foreground star has an orbiting planet, then a second, briefer brightness increase can occur. Zang et al. identified a microlensing event due to an exoplanet with a planet/star mass ratio between those of Earth and Neptune. They combined this object with a larger sample of planets detected using microlensing to constrain the abundance and population distribution of planets on Jupiter-like orbits. They found a bimodal distribution, which they interpreted as reflecting the formation mechanisms. —Keith T. Smith [ABSTRACT FROM AUTHOR] |
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| Database: | Psychology and Behavioral Sciences Collection |
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| 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. Editor's summary: Gravitational microlensing occurs when a foreground star passes between Earth and a background star, focusing light and causing an apparent increase in brightness. If the foreground star has an orbiting planet, then a second, briefer brightness increase can occur. Zang et al. identified a microlensing event due to an exoplanet with a planet/star mass ratio between those of Earth and Neptune. They combined this object with a larger sample of planets detected using microlensing to constrain the abundance and population distribution of planets on Jupiter-like orbits. They found a bimodal distribution, which they interpreted as reflecting the formation mechanisms. —Keith T. Smith [ABSTRACT FROM AUTHOR] |
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| ISSN: | 00368075 |
| DOI: | 10.1126/science.adn6088 |
