OGLE-2017-BLG-0448Lb: A Low Mass–Ratio Wide-orbit Microlensing Planet?
In: The Astronomical Journal, Jg. 167 (2024), Heft 4, S. 162-162
Online
academicJournal
Zugriff:
The gravitational microlensing technique is most sensitive to planets in a Jupiter-like orbit and has detected more than 200 planets. However, only a few wide-orbit ( s > 2) microlensing planets have been discovered, where s is the planet-to-host separation normalized to the angular Einstein ring radius, θ _E . Here, we present the discovery and analysis of a strong candidate wide-orbit microlensing planet in the event OGLE-2017-BLG-0448. The whole light curve exhibits long-term residuals to the static binary-lens single-source model, so we investigate the residuals by adding the microlensing parallax, microlensing xallarap, an additional lens, or an additional source. For the first time, we observe a complex degeneracy between all four effects. The wide-orbit models with s ∼ 2.5 and a planet-to-host mass ratio of q ∼ 10 ^−4 are significantly preferred, but we cannot rule out the close models with s ∼ 0.35 and q ∼ 10 ^−3 . A Bayesian analysis based on a Galactic model indicates that, despite the complicated degeneracy, the surviving wide-orbit models all contain a super-Earth-mass to Neptune-mass planet at a projected planet-host separation of ∼6 au and the surviving close-orbit models all consist of a Jovian-mass planet at ∼1 au. The host star is probably an M or K dwarf. We discuss the implications of this dimension-degeneracy disaster on microlensing light-curve analysis and its potential impact on statistical studies.
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OGLE-2017-BLG-0448Lb: A Low Mass–Ratio Wide-orbit Microlensing Planet?
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Autor/in / Beteiligte Person: | Zhai, Ruocheng ; Poleski, Radosław ; Zang, Weicheng ; Youn Kil Jung ; Udalski, Andrzej ; Kuang, Renkun ; Authors, Leading ; Albrow, Michael D. ; Chung, Sun-Ju ; Gould, Andrew ; Han, Cheongho ; Hwang, Kyu-Ha ; Ryu, Yoon-Hyun ; Shin, In-Gu ; Shvartzvald, Yossi ; Yang, Hongjing ; Yee, Jennifer C. ; Cha, Sang-Mok ; Kim, Dong-Jin ; Kim, Hyoun-Woo ; Kim, Seung-Lee ; Lee, Chung-Uk ; Lee, Dong-Joo ; Lee, Yongseok ; Park, Byeong-Gon ; Pogge, Richard W. ; The KMTNet Collaboration ; Skowron, Jan ; Szymański, Michał K. ; Soszyński, Igor ; Ulaczyk, Krzysztof ; Pietrukowicz, Paweł ; Kozłowski, Szymon ; Mróz, Przemek ; Rybicki, Krzysztof A. ; Iwanek, Patryk ; Wrona, Marcin ; Gromadzki, Mariusz ; The OGLE Collaboration ; Wang, Hanyue ; Mao, Shude ; Zhang, Jiyuan ; Qian, Qiyue ; Zhu, Wei ; The MAP Collaboration |
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Zeitschrift: | The Astronomical Journal, Jg. 167 (2024), Heft 4, S. 162-162 |
Veröffentlichung: | IOP Publishing, 2024 |
Medientyp: | academicJournal |
ISSN: | 1538-3881 (print) |
DOI: | 10.3847/1538-3881/ad284f |
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