论文标题
完善Star Kepler-33及其五个过境行星的质量和半径
Refining the Masses and Radii of the Star Kepler-33 and its Five Transiting Planets
论文作者
论文摘要
Kepler-33在5到41天内托管了五个经过验证的过境行星。行星在几乎共平面轨道中，表现出非常相似（适当尺度）的过境持续时间，指示相似的影响参数。外部三个行星的半径为$ 3.5 \ lyssim r _ {\ rm p}/r_ \ plus \ lessssim4.7$，并且动态地包装紧密，因此可以观察到过境时机变化。 Photodynamical analysis of transit timing variations provide $2σ$ upper bounds on the eccentricity of the orbiting planets (ranging from $<0.02$ to $<0.2$) and the mean density of the host-star ($0.39_{-0.02}^{+0.01}\,{\rm g/cm^3}$).我们将\ emph {gaia}早期数据释放3个视差观测，先前报道的宿主星星和金属性以及我们的光动力学模型以完善宿主星和过境行星的特性。我们的分析产生了Kepler-33〜E（$ 6.6 _ { - 1.0}^{+1.1} \，m_ \ oplus $）和F（$ 8.2 _ { - 1.2}^{+1.6} {+1.6} \，m_ \ oplus $ $ 2 $ $ <199 c（m m <199）， （$ <8.2 \，m_ \ oplus $）。我们确认了行星D的低散装密度（$ <0.4 \，{\ rm g/cm^3} $），E（$ 0.8 \ pm0.1 \，{\ rm g/cm^3} $）和f（$ 0.7 \ pm0.1 \，pm0.1 \，{\ rm g/cm g/cm cm^3} $）。 Based on comparisons with planetary evolution models, we find that Kepler-33~e and f exhibit relatively high envelope mass fractions of $f_{\rm env}=7.0_{-0.5}^{+0.6}\%$ and $f_{\rm env}=10.3\pm0.6\%$, respectively.假设Planet d $ \ sim4 \，m_ \ oplus $的质量表明它具有$ f _ {\ rm env} \ gtrsim12 \％$。
Kepler-33 hosts five validated transiting planets ranging in period from 5 to 41 days. The planets are in nearly co-planar orbits and exhibit remarkably similar (appropriately scaled) transit durations indicative of similar impact parameters. The outer three planets have radii of $3.5\lesssim R_{\rm p}/R_\oplus\lesssim4.7$ and are closely-packed dynamically, and thus transit timing variations can be observed. Photodynamical analysis of transit timing variations provide $2σ$ upper bounds on the eccentricity of the orbiting planets (ranging from $<0.02$ to $<0.2$) and the mean density of the host-star ($0.39_{-0.02}^{+0.01}\,{\rm g/cm^3}$). We combine \emph{Gaia} Early Data Release 3 parallax observations, the previously reported host-star effective temperature and metallicity, and our photodynamical model to refine properties of the host-star and the transiting planets. Our analysis yields well-constrained masses for Kepler-33~e ($6.6_{-1.0}^{+1.1}\,M_\oplus$) and f ($8.2_{-1.2}^{+1.6}\,M_\oplus$) along with $2σ$ upper limits for planets c ($<19\,M_\oplus$) and d ($<8.2\,M_\oplus$). We confirm the reported low bulk densities of planet d ($<0.4\,{\rm g/cm^3}$), e ($0.8\pm0.1\,{\rm g/cm^3}$), and f ($0.7\pm0.1\,{\rm g/cm^3}$). Based on comparisons with planetary evolution models, we find that Kepler-33~e and f exhibit relatively high envelope mass fractions of $f_{\rm env}=7.0_{-0.5}^{+0.6}\%$ and $f_{\rm env}=10.3\pm0.6\%$, respectively. Assuming a mass for planet d $\sim4\,M_\oplus$ suggests that it has $f_{\rm env}\gtrsim12\%$.
