Nagakane, M, Lee, C-H, Koshimoto, N, Suzuki, D, Udalski, A, Beaulieu, JP, Sumi, T, Bennett, DP, Bond, IA, Rattenbury, N, Bachelet, E, Dominik, M, Abe, F, Barry, RK, Bhattacharya, A, Donachie, M, Fujii, H, Fukui, A, Hirao, Y, Itow, Y, Kamei, Y, Kondo, I, Li, MCA, Matsubara, Y, Matsuo, T, Miyazaki, S, Muraki, Y, Ranc, C, Shibai, H, Suematsu, H, Sullivan, DJ, Tristram, PJ, Yamakawa, T, Yonehara, A, Mróz, P, Poleski, R, Skowron, J, Szymański, MK, Soszyński, I, Pietrukowicz, P, lowski, SK, Ulaczyk, K, Bramich, DM, Cassan, A, Jaimes, RF, Horne, K, Hundertmark, M, Mao, S, Menzies, J, Schmidt, R, Snodgrass, C, Steele, IA, Street, R, Tsapras, Y, Wambsganss, J, Jørgensen, UG, Bozza, V, a, PL, Peixinho, N, Skottfelt, J, Southworth, J, Andersen, MI, Burgdorf, MJ, D’Ago, G, Evans, DF, Hinse, TC, Korhonen, H, Rabus, M and Rahvar, S (2019) OGLE-2015-BLG-1649Lb: A Gas Giant Planet around a Low-mass Dwarf. Astronomical Journal, 158 (5). 212 -212. ISSN 0004-6256

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We report the discovery of an exoplanet from the analysis of the gravitational microlensing event OGLE-2015-BLG-1649 that challenges the core accretion model of planet formation and appears to support the disk instability model. The planet/host-star mass ratio is q = 7.2 × 10−3 and the projected separation normalized to the angular Einstein radius is s = 0.9. We conducted high-resolution follow-up observations using the Infrared Camera and Spectrograph (IRCS) camera on the Subaru telescope and are able to place an upper limit on the lens flux. From these measurements we are able to exclude all host stars greater than or equal in mass to a G-type dwarf. We conducted a Bayesian analysis with these new flux constraints included as priors resulting in estimates of the masses of the host star and planet. These are M L = 0.34 ± 0.19 M ⊙ and , respectively. The distance to the system is . The projected star–planet separation is . The estimated relative lens-source proper motion, ∼7.1 mas yr−1, is fairly high and thus the lens can be better constrained if additional follow-up observations are conducted several years after the event.

Item Type: Article
Additional Information: © IOP Publishing. This is the final published version of the article (version of record). It first appeared online via IOP Publishing Ltd. at Please refer to any applicable terms of use of the publisher.
Uncontrolled Keywords: galactic bulge, camera, stars, model, host
Subjects: Q Science > QB Astronomy > QB600 Planets. Planetology
Q Science > QB Astronomy > QB799 Stars
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Depositing User: Symplectic
Date Deposited: 09 Dec 2019 10:24
Last Modified: 18 Dec 2019 11:19

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