ﻻ يوجد ملخص باللغة العربية
We report the discovery of a planet in the microlensing event OGLE-2018-BLG-1269, with planet-host mass ratio $q sim 6times10^{-4}$, i.e., $0.6$ times smaller than the Jupiter/Sun mass ratio. Combined with the $Gaia$ parallax and proper motion, a strong one-dimensional constraint on the microlens parallax vector allows us to significantly reduce the uncertainties of lens physical parameters. A Bayesian analysis that ignores any information about light from the host yields that the planet is a cold giant $(M_{2} = 0.69_{-0.22}^{+0.44},M_{rm J})$ orbiting a Sun-like star $(M_{1} = 1.13_{-0.35}^{+0.72},M_{odot})$ at a distance of $D_{rm L} = 2.56_{-0.62}^{+0.92},{rm kpc}$. The projected planet-host separation is $a_{perp} = 4.61_{-1.17}^{+1.70},{rm au}$. Using {it Gaia} astrometry, we show that the blended light lies $lesssim 12,$mas from the host and therefore must be either the host star or a stellar companion to the host. An isochrone analysis favors the former possibility at $>99.6%$. The host is therefore a subgiant. For host metallicities in the range of $0.0 leq {rm [Fe/H]} leq +0.3$, the host and planet masses are then in the range of $1.16 leq M_{1}/M_{odot} leq 1.38$ and $0.74 leq M_{2}/M_{rm J} leq 0.89$, respectively. Low host metallicities are excluded. The brightness and proximity of the lens make the event a strong candidate for spectroscopic followup both to test the microlensing solution and to further characterize the system.
We report the discovery of the planet OGLE-2018-BLG-0532Lb, with very obvious signatures in the light curve that lead to an estimate of the planet-host mass ratio $q=M_{rm planet}/M_{rm host}simeq 1times10^{-4}$. Although there are no obvious systema
We report the discovery of a Jupiter-mass planet orbiting an M-dwarf star that gave rise to the microlensing event OGLE-2011-BLG-0265. Such a system is very rare among known planetary systems and thus the discovery is important for theoretical studie
We report the discovery of a several-Jupiter mass planetary companion to the primary lens star in microlensing event OGLE-2005-BLG-071. Precise (<1%) photometry at the peak of the event yields an extremely high signal-to-noise ratio detection of a de
We report the discovery of KMT-2018-BLG-1292Lb, a super-Jovian $M_{rm planet} = 4.5pm 1.3,M_J$ planet orbiting an F or G dwarf $M_{rm host} = 1.5pm 0.4,M_odot$, which lies physically within ${cal O}(10,pc)$ of the Galactic plane. The source star is a
We report the discovery and analysis of a sub-Saturn-mass planet in the microlensing event OGLE-2018-BLG-0799. The planetary signal was observed by several ground-based telescopes, and the planet-host mass ratio is $q = (2.65 pm 0.16) times 10^{-3}$.