OGLE-2018-BLG-1185b : A Low-Mass Microlensing Planet Orbiting a Low-Mass Dwarf

Autor: Man Cheung Alex Li, Yuri I. Fujii, H.-W. Kim, Michael D. Albrow, Valerio Bozza, Igor Soszyński, Hirosane Fujii, Patryk Iwanek, John Southworth, Yossi Shvartzvald, S. Kozlowski, Hikaru Shoji, Iona Kondo, Yuki Hirao, S. Ishitani Silva, M. T. Penny, Sean Carey, J. Campbell-White, Nicholas J. Rattenbury, Jan Skowron, D. Maoz, Joachim Wambsganss, Penélope Longa-Peña, G. Bryden, D.-J. Kim, Yuki Satoh, Takahiro Sumi, S. Calchi Novati, S. J. Chung, David P. Bennett, Akihiko Fukui, Shude Mao, Sohrab Rahvar, Shinyoung Kim, U. G. Jørgensen, Yiannis Tsapras, B. S. Gaudi, Yasushi Muraki, Yongseok Lee, Atsunori Yonehara, Fumio Abe, Andrzej Udalski, Ian A. Bond, Keith Horne, Daisuke Suzuki, J. Tregloan-Reed, Arnaud Cassan, Jesper Skottfelt, Yoshitaka Itow, Paul J. Tristram, Colin Snodgrass, Michał K. Szymański, Nuno Peixinho, R. W. Pogge, Shota Miyazaki, Wei Zhu, M. Wrona, C.-U. Lee, Greg Olmschenk, Duk-Hang Lee, Sang-Mok Cha, Byeong-Gon Park, E. Khalouei, Kyu-Ha Hwang, Youn Kil Jung, P. Pietrukowicz, Radosław Poleski, Naoki Koshimoto, P. Mróz, C. A. Beichman, Yoshimi Matsubara, Andrew Gould, Clément Ranc, Martin Dominik, R. A. Street, Weicheng Zang, Rintaro Kirikawa, Yuzuru Tanaka, Martin Donachie, C. Han, Richard K. Barry, Tobias C. Hinse, Krzysztof Ulaczyk, M. Hundertmark, Abhijit Saha, Sami Dib, Aparna Bhattacharya, Martin Burgdorf, Krzysztof A. Rybicki, Tsubasa Yamawaki, Yoon-Hyun Ryu, Calen B. Henderson, Sedighe Sajadian, Jennifer C. Yee, Etienne Bachelet, M. Rabus, D. M. Bramich, In-Gu Shin
Přispěvatelé: European Commission, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science
Jazyk: angličtina
Rok vydání: 2021
Předmět:
010504 meteorology & atmospheric sciences
Star (game theory)
FOS: Physical sciences
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Gravitational microlensing
Q1
01 natural sciences
Gravitational microlensing exoplanet detection
Spitzer Space Telescope
0103 physical sciences
QB460
QB Astronomy
Astrophysics::Solar and Stellar Astrophysics
Satellite microlensing parallax
010303 astronomy & astrophysics
QB600
QC
Astrophysics::Galaxy Astrophysics
0105 earth and related environmental sciences
QB
Physics
Earth and Planetary Astrophysics (astro-ph.EP)
Astronomy and Astrophysics
3rd-DAS
Planetary system
Mass ratio
Light curve
Exoplanet
QC Physics
13. Climate action
Space and Planetary Science
Astrophysics::Earth and Planetary Astrophysics
Low Mass
Astrophysics - Earth and Planetary Astrophysics
Zdroj: The Astronomical Journal
ISSN: 0004-6256
Popis: We report the analysis of planetary microlensing event OGLE-2018-BLG-1185, which was observed by a large number of ground-based telescopes and by the $Spitzer$ Space Telescope. The ground-based light curve indicates a low planet-host star mass ratio of $q = (6.9 \pm 0.2) \times 10^{-5}$, which is near the peak of the wide-orbit exoplanet mass-ratio distribution. We estimate the host star and planet masses with a Bayesian analysis using the measured angular Einstein radius under the assumption that stars of all masses have an equal probability to host this planet. The flux variation observed by $Spitzer$ was marginal, but still places a constraint on the microlens parallax. Imposing a conservative constraint that this flux variation should be $\Delta f_{\rm Spz} < 4$ instrumental flux units indicates a host mass of $M_{\rm host} = 0.37^{+0.35}_{-0.21}\ M_\odot$ and a planet mass of $m_{\rm p} = 8.4^{+7.9}_{-4.7}\ M_\oplus$. A Bayesian analysis including the full parallax constraint from $Spitzer$ suggests smaller host star and planet masses of $M_{\rm host} = 0.091^{+0.064}_{-0.018}\ M_\odot$ and $m_{\rm p} = 2.1^{+1.5}_{-0.4}\ M_\oplus$, respectively. Future high-resolution imaging observations with $HST$ or ELTs could distinguish between these two scenarios and help to reveal the planetary system properties in more detail.
Comment: 30 pages, 11 figures, 5 tables, Accepted for publication in Astronomical Journal (AJ)
Databáze: OpenAIRE