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A companion on the planet/brown dwarf mass boundary on a wide orbit discovered by gravitational microlensing

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journal contribution
posted on 2023-05-19, 17:11 authored by Poleski, R, Udalski, A, Bond, IA, Jean-Philippe BeaulieuJean-Philippe Beaulieu, Clanton, C, Gaudi, S, Szymanski, MK, Soszynski, I, Pietrukowicz, P, Kozlowski, S, Skowron, J, Wyrzykowski, A, Ulaczyk, K, Bennett, DP, Sumi, T, Suzuki, D, Rattenbury, NJ, Koshimoto, N, Abe, F, Asakura, Y, Barry, RK, Bhattacharya, A, Donachie, M, Evans, P, Fukui, A, Hirao, Y, Itow, Y, Li, MCA, Ling, CH, Masuda, K, Matsubara, Y, Muraki, Y, Nagakane, M, Ohnishi, K, Ranc, C, Saito, T, Sharan, A, Sullivan, DJ, Tristram, PJ, Yamada, T, Yonehara, A, Batista, V, Marquette, JB
We present the discovery of a substellar companion to the primary host lens in the microlensing event MOA-2012-BLG-006. The companion-to-host mass ratio is 0.016, corresponding to a companion mass of ≈8 MJup(M*/0.5 Mʘ). Thus, the companion is either a high-mass giant planet or a low-mass brown dwarf, depending on the mass of the primary M*. The companion signal was separated from the peak of the primary event by a time that was as much as four times longer than the event timescale. We therefore infer a relatively large projected separation of the companion from its host of ≈10 au(M*/0.5 Mʘ)1/2 for a wide range (3-7 kpc) of host star distances from the Earth. We also challenge a previous claim of a planetary companion to the lens star in microlensing event OGLE-2002-BLG-045.


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Astronomy and Astrophysics



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School of Natural Sciences


EDP Science

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