MOA-2022-BLG-249Lb: Nearby microlensing super-Earth planet detected from high-cadence surveys

Han, Cheongho; Gould, Andrew; Jung, Youn Kil; Bond, Ian A.; Zang, Weicheng; Chung, Sun-Ju; Albrow, Michael D.; Hwang, Kyu-Ha; Ryu, Yoon-Hyun; Shin, In-Gu; Shvartzvald, Yossi; Yang, Hongjing; Yee, Jennifer C.; Cha, Sang-Mok; Kim, Doeon; Kim, Dong-Jin; Kim, Seung-Lee; Lee, Chung-Uk; Lee, Dong-Joo; Lee, Yongseok; Park, Byeong-Gon; Pogge, Richard W.; Mao, Shude; Zhu, Wei; Abe, Fumio; Barry, Richard; Bennett, David P.; Bhattacharya, Aparna; Fujii, Hirosame; Fukui, Akihiko; Hamada, Ryusei; Hirao, Yuki; Ishitani Silva, Stela; Itow, Yoshitaka; Kirikawa, Rintaro; Kondo, Iona; Koshimoto, Naoki; Matsubara, Yutaka; Matsumoto, Sho; Miyazaki, Shota; Muraki, Yasushi; Okamura, Arisa; Olmschenk, Greg; Ranc, Clément; Rattenbury, Nicholas J.; Satoh, Yuki; Sumi, Takahiro; Suzuki, Daisuke; Toda, Taiga; Tomoyoshi, Mio; Tristram, Paul J.; Vandorou, Aikaterini; Yama, Hibiki; Yamashita, Kansuke
Bibliographical reference

Astronomy and Astrophysics

Advertised on:
6
2023
Number of authors
54
IAC number of authors
1
Citations
4
Refereed citations
4
Description

Aims: We investigate the data collected by the high-cadence microlensing surveys during the 2022 season in search of planetary signals appearing in the light curves of microlensing events. From this search, we find that the lensing event MOA-2022-BLG-249 exhibits a brief positive anomaly that lasted for about one day, with a maximum deviation of ~0.2 mag from a single-source, single-lens model.
Methods: We analyzed the light curve under the two interpretations of the anomaly: one originated by a low-mass companion to the lens (planetary model) and the other originated by a faint companion to the source (binary-source model).
Results: We find that the anomaly is better explained by the planetary model than the binary-source model. We identified two solutions rooted in the inner-outer degeneracy and for both of them, the estimated planet-to-host mass ratio, q ~ 8 × 10−5, is very small. With the constraints provided by the microlens parallax and the lower limit on the Einstein radius, as well as the blend-flux constraint, we find that the lens is a planetary system, in which a super-Earth planet, with a mass of (4.83 ± 1.44) Μ⊕, orbits a low-mass host star, with a mass of (0.18 ± 0.05) M⊙, lying in the Galactic disk at a distance of (2.00 ± 0.42) kpc. The planet detection demonstrates the elevated microlensing sensitivity of the current high-cadence lensing surveys to low-mass planets.
Type