OGLE-2013-BLG-0132Lb and OGLE-2013-BLG-1721Lb: Two Saturn-mass Planets Discovered around M-dwarfs
journal contributionposted on 15.05.2018, 12:42 by P. Mróz, A. Udalski, I. A. Bond, J. Skowron, T. Sumi, C. Han, M. K. Szymański, I. Soszyński, R. Poleski, P. Pietrukowicz, S. Kozłowski, L. Wyrzykowski, K. Ulaczyk, F. Abe, Y. Asakura, R. K. Barry, D. P. Bennett, A. Bhattacharya, M. Donachie, Philip Evans, A. Fukui, Y. Hirao, Y. Itow, N. Koshimoto, M. C. A. Li, C. H. Ling, K. Masuda, Y. Matsubara, Y. Muraki, M. Nagakane, K. Ohnishi, C. Ranc, N. J. Rattenbury, T. Saito, A. Sharan, D. J. Sullivan, D. Suzuki, P. J. Tristram, T. Yamada, A. Yonehara
We present the discovery of two planetary systems consisting of a Saturn-mass planet orbiting an M-dwarf, which were detected in faint microlensing events OGLE-2013-BLG-0132 and OGLE-2013-BLG-1721. The planetary anomalies were covered with high cadence by Optical Gravitational Lensing Experiment (OGLE) and Microlensing Observations in Astrophysics (MOA) photometric surveys. The light curve modeling indicates that the planet-to-host mass ratios are (5.15 ± 0.28) × 10 -4 and (13.18 ± 0.72) × 10 -4 , respectively. Both events were too short and too faint to measure a reliable parallax signal and hence the lens mass. We therefore used a Bayesian analysis to estimate the masses of both planets: - 0.29 -0.13 +0.16 M Jup (OGLE-2013-BLG-0132Lb) and - 0.64 -0.31 +0.35 M Jup (OGLE-2013-BLG-1721Lb). Thanks to a high relative proper motion, OGLE-2013-BLG-0132 is a promising candidate for the high-resolution imaging follow-up. Both planets belong to an increasing sample of sub-Jupiter-mass planets orbiting M-dwarfs beyond the snow line.