AI 中文总结
通过分析2025年银河系中心微引力透镜观测季发现的两个事件，揭示两颗行星伴星。光变曲线建模得出质量比，贝叶斯分析估计透镜系统物理参数，发现两颗行星质量与天王星相当且在宿主恒星雪线距离之外。
AI 中文摘要
我们对2025年银河系中心微引力透镜观测季通过高频率巡天观测发现的两个行星微引力透镜事件KMT-2025-BLG-0975和KMT-2025-BLG-1160进行了分析。在这两个事件中，透镜光变曲线峰值附近的短持续时间异常揭示了行星伴星的存在。光变曲线建模得出KMT-2025-BLG-0975的行星与宿主恒星质量比为q = 8.6×10⁻⁴，KMT-2025-BLG-1160的为1.3×10⁻⁴。对KMT-2025-BLG-0975检测到了有限源效应，得以测量角爱因斯坦半径，而KMT-2025-BLG-1160仅获得了该量的下限。我们通过贝叶斯分析，根据测量的微引力透镜可观测量来估计透镜系统的物理参数。结果表明，KMT-2025-BLG-0975Lb的行星伴星质量为M_p = 29.8⁺⁵⁰.⁵₋₁₆.₀ M⊕，KMT-2025-BLG-1160Lb的为25.4⁺¹⁵.⁵₋₁₄.₁ M⊕。两颗行星的质量都与天王星相当。宿主恒星推断，KMT-2025-BLG-0975L为质量M_h = 0.10⁺⁰.¹⁸₋₀.₀₆ M⊙的低质量M矮星，KMT-2025-BLG-1160L为质量M_h = 0.58⁺⁰.³⁵₋₀.³² M⊙的晚期K矮星。KMT-2025-BLG-0975Lb的投影行星-宿主间距为a⊥ = 0.81⁺⁰.¹⁰₋₀.¹¹ au，KMT-2025-BLG-1160Lb的内解和宽解的投影行星-宿主间距分别为a⊥ = 2.56⁺⁰.⁴⁸₋₀.₇₁ au和3.29⁺⁰.⁶¹₋₀.₉₂ au。在这两个系统中，行星都位于其宿主恒星预期雪线距离之外，处于冷冰巨星状态。
英文摘要
We present the analysis of two planetary microlensing events, KMT-2025-BLG-0975 and KMT-2025-BLG-1160, discovered during the 2025 Galactic bulge microlensing season through high-cadence survey observations. In both events, short-duration anomalies near the peaks of the lensing light curves reveal the presence of planetary companions. Light-curve modeling yields planet-to-host mass ratios of $q = 8.6 \times 10^{-4}$ for KMT-2025-BLG-0975 and $1.3 \times 10^{-4}$ for KMT-2025-BLG-1160. For KMT-2025-BLG-0975, finite-source effects are detected, enabling a measurement of the angular Einstein radius, whereas only a lower limit on this quantity is obtained for KMT-2025-BLG-1160. We estimate the physical parameters of the lens systems through Bayesian analyses constrained by the measured microlensing observables. The results indicate that the planetary companions have masses of $M_{\rm p}=29.8^{+50.5}_{-16.0}~M_\oplus$ for KMT-2025-BLG-0975Lb and $25.4^{+15.5}_{-14.1}~M_\oplus$ for KMT-2025-BLG-1160Lb. Both planets have masses comparable to that of Uranus. The host stars are inferred to be a low-mass M dwarf with a mass of $M_{\rm h}=0.10^{+0.18}_{-0.06}~M_\odot$ for KMT-2025-BLG-0975L and a late K dwarf with a mass of $M_{\rm h}=0.58^{+0.35}_{-0.32}~M_\odot$ for KMT-2025-BLG-1160L. The projected planet--host separations are $a_\perp=0.81^{+0.10}_{-0.11}$~au for KMT-2025-BLG-0975Lb and $a_\perp=2.56^{+0.48}_{-0.71}$~au and $3.29^{+0.61}_{-0.92}$~au for the inner and wide solutions, respectively, of KMT-2025-BLG-1160Lb. In both systems, the planets are located beyond the expected snow-line distances of their hosts, placing them in the cold ice-giant regime.
Comments11 pages, 7 figures
