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arXiv 1004.3538astro-ph.EPastro-ph.IM
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Kepler-4 b到Kepler-8b的独立分析

An Independent Analysis of Kepler-4b through Kepler-8b

David M. Kipping, Gáspár Á. Bakos

摘要:

我们提出了两个独立的,均匀的,全球性的分析的过境光变曲线,径向速度和光谱的开普勒-4b到开普勒-8b,与以前的方法有许多差异。其中包括:1)改进的去相关参数拟合集; 2)新的临边暗化系数; 3)修改为BJD的时间戳以与RV一致; 4)补偿Kepler LC数据的积分时间的两种不同方法; 5)最佳拟合的二次日食深度和排除的上限; 6)拟合的中间过境时间、持续时间、深度和单个过境的基线通量。我们做了几个新的测定:1)我们探测到开普勒-7b的二次日食,深度为(47+/-14)ppm,显著性为3.5-sigma。我们得出结论,反射光是一个更合理的起源比热发射,并确定了一个几何常数Ag=(0.38+/-0.12)。2)海王星质量行星Kepler-4 b的偏心轨道模型在2 sigma置信度下勉强检测到e=(0.25+/-0.12)。如果得到证实,这将使开普勒-4b与GJ 436 b和HAT-P-11b类似,是一颗偏心的海王星质量行星。3)我们发现了Kepler-5 b深度为(26+/-17)ppm的二次日食的边缘(2-sigma)证据。最合理的解释是由Ag=(0.15+/-0.10)的行星引起的反射光。4)开普勒-6b TTV周期图中的2.6西格玛峰被检测到,并且不容易被解释为混叠频率。我们发现,共振/非共振扰动,特洛伊或exomoon都提供不充分的解释,最有可能的来源是恒星旋转。5)在大多数情况下,我们发现不同的碰撞参量相对于发现文件,但一般自洽。6)我们使用凌日时间来限制共振行星、系外卫星和特洛伊人的存在。

英文摘要:

We present two independent, homogeneous, global analyses of the transit light curves, radial velocities and spectroscopy of Kepler-4b through Kepler-8b, with numerous differences over the previous methods. These include: 1) improved decorrelated parameter fitting set, 2) new limb darkening coefficients, 3) time-stamps modified to BJD for consistency with RV, 4) two different methods for compensating for the integration-time of Kepler LC-data, 5) best-fit secondary-eclipse depths and excluded upper limits, 6) fitted mid-transit times, durations, depths and baseline fluxes for individual transits. We make several new determinations: 1) We detect a secondary eclipse for Kepler-7b of depth (47+/-14)ppm and significance 3.5-sigma. We conclude reflected light is a more plausible origin than thermal emission and determine a geometric albedo of Ag=(0.38+/-0.12). 2) An eccentric-orbit model for the Neptune-mass planet Kepler-4b is marginally detected to 2-sigma confidence with e=(0.25+/-0.12). If confirmed, this would place Kepler-4b in a similar category as GJ436b and HAT-P-11b as an eccentric, Neptune-mass planet. 3) We find marginal (2-sigma) evidence for Kepler-5b's secondary eclipse of depth (26+/-17)ppm. The most plausible explanation is reflected light caused by a planet with Ag=(0.15+/-0.10). 4) A 2.6-sigma peak in Kepler-6b TTV periodogram is detected and is not easily explained as an aliased frequency. We find that a resonant/non-resonant perturber, Trojan or exomoon all provide inadequate explanations and the most likely source is stellar rotation. 5) We find different impact parameters relative to the discovery papers in most cases, but generally self-consistent. 6) We constrain the presence of resonant planets, exomoons and Trojans using transit timing.

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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