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arXiv 1503.09184astro-ph.EP
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WASP-6行星系中的凌日和星点

Transits and starspots in the WASP-6 planetary system

Jeremy Tregloan-Reed, John Southworth, M. Burgdorf, S. Calchi Novati, M. Dominik, F. Finet, U. G. Jørgensen, G. Maier, L. Mancini, S. Proft, D. Ricci, C. Snodgr… 展开作者

Jeremy Tregloan-Reed, John Southworth, M. Burgdorf, S. Calchi Novati, M. Dominik, F. Finet, U. G. Jørgensen, G. Maier, L. Mancini, S. Proft, D. Ricci, C. Snodgrass, V. Bozza, P. Browne, P. Dodds, T. Gerner, K. Harpsøe, T. C. Hinse, M. Hundertmark, N. Kains, E. Kerins, C. Liebig, M. T. Penny, S. Rahvar, K. Sahu, G. Scarpetta, S. Schäfer, F. Schönebeck, J. Skottfelt, J. Surdej

摘要:

我们提出了更新\textsc{prism},光度过境星点模型,\textsc{gemc},混合优化代码MCMC和遗传算法相结合。然后,我们提出了高精度测光的四个过境的WASP-6行星系,其中两个包含一个恒星黑子异常。使用\textsc{prism}和\textsc{gemc}对所有四个凌日进行建模,并计算系统的物理性质。我们发现主星的质量和半径分别为$0.836\pm 0.063\,{\rm M}_\odot$和$0.864\pm0.024\,{\rm R}_\odot$。对于行星,我们发现质量为$0.485\pm 0.027\,{\rm M}_{\rm Jup}$,半径为$1.230\pm0.035\,{\rm R}_{\rm Jup}$,密度为$0.244\pm0.014\,ρ_{\rm Jup}$。这些值与文献中发现的值一致。在可能的假设,这两个点的异常是由相同的星点或星点复合体,我们测量的恒星旋转周期和速度是$23.80 \pm 0.15$ \,d和$1.78 \pm 0.20$ \,km\,s $^{-1}$,分别在75.8 $^\circ$的同纬度。我们发现恒星自转轴和行星轨道轴之间的天空投影角是$λ= 7.2^{\circ} \pm 3.7^{\circ}$,表明轴向对齐。我们的研究结果是一致的,更精确的比发表的光谱测量的Rossiter-McLaughlin效应。这些结果表明,WASP-6 b形成于距离其宿主恒星更远的地方,并通过与原行星盘的潮汐相互作用而遭受轨道衰变。

英文摘要:

We present updates to \textsc{prism}, a photometric transit-starspot model, and \textsc{gemc}, a hybrid optimisation code combining MCMC and a genetic algorithm. We then present high-precision photometry of four transits in the WASP-6 planetary system, two of which contain a starspot anomaly. All four transits were modelled using \textsc{prism} and \textsc{gemc}, and the physical properties of the system calculated. We find the mass and radius of the host star to be $0.836\pm 0.063\,{\rm M}_\odot$ and $0.864\pm0.024\,{\rm R}_\odot$, respectively. For the planet we find a mass of $0.485\pm 0.027\,{\rm M}_{\rm Jup}$, a radius of $1.230\pm0.035\,{\rm R}_{\rm Jup}$ and a density of $0.244\pm0.014\,ρ_{\rm Jup}$. These values are consistent with those found in the literature. In the likely hypothesis that the two spot anomalies are caused by the same starspot or starspot complex, we measure the stars rotation period and velocity to be $23.80 \pm 0.15$\,d and $1.78 \pm 0.20$\,km\,s$^{-1}$, respectively, at a co-latitude of 75.8$^\circ$. We find that the sky-projected angle between the stellar spin axis and the planetary orbital axis is $λ= 7.2^{\circ} \pm 3.7^{\circ}$, indicating axial alignment. Our results are consistent with and more precise than published spectroscopic measurements of the Rossiter-McLaughlin effect. These results suggest that WASP-6\,b formed at a much greater distance from its host star and suffered orbital decay through tidal interactions with the protoplanetary disc.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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