The Astronomical Journal (Jan 2024)
OGLE-2017-BLG-0448Lb: A Low Mass–Ratio Wide-orbit Microlensing Planet?
- Ruocheng Zhai,
- Radosław Poleski,
- Weicheng Zang,
- Youn Kil Jung,
- Andrzej Udalski,
- Renkun Kuang,
- Leading Authors,
- Michael D. Albrow,
- Sun-Ju Chung,
- Andrew Gould,
- Cheongho Han,
- Kyu-Ha Hwang,
- Yoon-Hyun Ryu,
- In-Gu Shin,
- Yossi Shvartzvald,
- Hongjing Yang,
- Jennifer C. Yee,
- Sang-Mok Cha,
- Dong-Jin Kim,
- Hyoun-Woo Kim,
- Seung-Lee Kim,
- Chung-Uk Lee,
- Dong-Joo Lee,
- Yongseok Lee,
- Byeong-Gon Park,
- Richard W. Pogge,
- The KMTNet Collaboration,
- Jan Skowron,
- Michał K. Szymański,
- Igor Soszyński,
- Krzysztof Ulaczyk,
- Paweł Pietrukowicz,
- Szymon Kozłowski,
- Przemek Mróz,
- Krzysztof A. Rybicki,
- Patryk Iwanek,
- Marcin Wrona,
- Mariusz Gromadzki,
- The OGLE Collaboration,
- Hanyue Wang,
- Shude Mao,
- Jiyuan Zhang,
- Qiyue Qian,
- Wei Zhu,
- The MAP Collaboration
Affiliations
- Ruocheng Zhai
- ORCiD
- Department of Astronomy, Tsinghua University , Beijing 100084, People's Republic of China
- Radosław Poleski
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Weicheng Zang
- ORCiD
- Department of Astronomy, Tsinghua University , Beijing 100084, People's Republic of China; Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA
- Youn Kil Jung
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea; University of Science and Technology , Korea, (UST), 217 Gajeong-ro Yuseong-gu, Daejeon 34113, Republic of Korea
- Andrzej Udalski
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Renkun Kuang
- ORCiD
- Department of Astronomy, Tsinghua University , Beijing 100084, People's Republic of China; Department of Engineering Physics, Tsinghua University , Beijing 100084, People's Republic of China
- Leading Authors
- Michael D. Albrow
- ORCiD
- University of Canterbury, Department of Physics and Astronomy , Private Bag 4800, Christchurch 8020, New Zealand
- Sun-Ju Chung
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea
- Andrew Gould
- Max-Planck-Institute for Astronomy , Königstuhl 17, 69117 Heidelberg, Germany; Department of Astronomy, Ohio State University , 140 W. 18th Avenue, Columbus, OH 43210, USA
- Cheongho Han
- Department of Physics, Chungbuk National University , Cheongju 28644, Republic of Korea
- Kyu-Ha Hwang
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea
- Yoon-Hyun Ryu
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea
- In-Gu Shin
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA
- Yossi Shvartzvald
- Department of Particle Physics and Astrophysics , Weizmann Institute of Science, Rehovot 76100, Israel
- Hongjing Yang
- ORCiD
- Department of Astronomy, Tsinghua University , Beijing 100084, People's Republic of China
- Jennifer C. Yee
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA
- Sang-Mok Cha
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea; School of Space Research, Kyung Hee University , Yongin, Kyeonggi 17104, Republic of Korea
- Dong-Jin Kim
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea
- Hyoun-Woo Kim
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea
- Seung-Lee Kim
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea
- Chung-Uk Lee
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea
- Dong-Joo Lee
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea
- Yongseok Lee
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea; School of Space Research, Kyung Hee University , Yongin, Kyeonggi 17104, Republic of Korea
- Byeong-Gon Park
- Korea Astronomy and Space Science Institute , Daejon 34055, Republic of Korea; University of Science and Technology , Korea, (UST), 217 Gajeong-ro Yuseong-gu, Daejeon 34113, Republic of Korea
- Richard W. Pogge
- Department of Astronomy, Ohio State University , 140 W. 18th Avenue, Columbus, OH 43210, USA
- The KMTNet Collaboration
- Jan Skowron
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Michał K. Szymański
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Igor Soszyński
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Krzysztof Ulaczyk
- ORCiD
- Department of Physics, University of Warwick , Gibbet Hill Road, Coventry, CV4 7AL, UK
- Paweł Pietrukowicz
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Szymon Kozłowski
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Przemek Mróz
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Krzysztof A. Rybicki
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland; Department of Particle Physics and Astrophysics , Weizmann Institute of Science, Rehovot 76100, Israel
- Patryk Iwanek
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Marcin Wrona
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- Mariusz Gromadzki
- ORCiD
- Astronomical Observatory, University of Warsaw , Al. Ujazdowskie 4, 00-478 Warszawa, Poland
- The OGLE Collaboration
- Hanyue Wang
- Center for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA
- Shude Mao
- Department of Astronomy, Tsinghua University , Beijing 100084, People's Republic of China
- Jiyuan Zhang
- Department of Astronomy, Tsinghua University , Beijing 100084, People's Republic of China
- Qiyue Qian
- Department of Astronomy, Tsinghua University , Beijing 100084, People's Republic of China
- Wei Zhu
- ORCiD
- Department of Astronomy, Tsinghua University , Beijing 100084, People's Republic of China
- The MAP Collaboration
- DOI
- https://doi.org/10.3847/1538-3881/ad284f
- Journal volume & issue
-
Vol. 167,
no. 4
p. 162
Abstract
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.
Keywords
