학술논문
OGLE-2012-BLG-0563Lb: a Saturn-mass Planet around an M Dwarf with the Mass Constrained by Subaru AO imaging
Document Type
Working Paper
Author
Fukui, A.; Gould, A.; Sumi, T.; Bennett, D. P.; Bond, I. A.; Han, C.; Suzuki, D.; Beaulieu, J. -P.; Batista, V.; Udalski, A.; Street, R. A.; Tsapras, Y.; Hundertmark, M.; Abe, F.; Bhattacharya, A.; Freeman, M.; Itow, Y.; Ling, C. H.; Koshimoto, N.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Ohnishi, K.; Philpott, L. C.; Rattenbury, N.; Saito, T.; Sullivan, D. J.; Tristram, P. J.; Yonehara, A.; Choi, J. -Y.; Christie, G. W.; DePoy, D. L.; Dong, Subo; Drummond, J.; Gaudi, B. S.; Hwang, K. -H.; Kavka, A.; Lee, C. U.; McCormick, J.; Natusch, T.; Ngan, H.; Park, H.; Pogge, R. W.; Shin, I-G.; Tan, T. -G.; Yee, J. C.; Szymański, M. K.; Pietrzyński, G.; Soszyński, I.; Poleski, R.; Kozłowski, S.; Pietrukowicz, P.; Ulaczyk, K.; Bramich, Ł. Wyrzykowski D. M.; Browne, P.; Dominik, M.; Horne, K.; Ipatov, S.; Kains, N.; Snodgrass, C.; Steele, I. A.
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Subject
Language
Abstract
We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with the planet-star mass ratio ~1 x 10^{-3}. Intensive photometric observations of a high-magnification microlensing event allow us to detect a clear signal of the planet. Although no parallax signal is detected in the light curve, we instead succeed at detecting the flux from the host star in high-resolution JHK'-band images obtained by the Subaru/AO188 and IRCS instruments, allowing us to constrain the absolute physical parameters of the planetary system. With the help of a spectroscopic information about the source star obtained during the high-magnification state by Bensby et al., we find that the lens system is located at 1.3^{+0.6}_{-0.8} kpc from us, and consists of an M dwarf (0.34^{+0.12}_{-0.20} M_sun) orbited by a Saturn-mass planet (0.39^{+0.14}_{-0.23} M_Jup) at the projected separation of 0.74^{+0.26}_{-0.42} AU (close model) or 4.3^{+1.5}_{-2.5} AU (wide model). The probability of contamination in the host star's flux, which would reduce the masses by a factor of up to three, is estimated to be 17%. This possibility can be tested by future high-resolution imaging. We also estimate the (J-Ks) and (H-Ks) colors of the host star, which are marginally consistent with a low metallicity mid-to-early M dwarf, although further observations are required for the metallicity to be conclusive. This is the fifth sub-Jupiter-mass (0.2