Utilizing Photometry from Multiple Sources to Mitigate Stellar Variability in Precise Radial Velocities: A Case Study of Kepler-21
Corey Beard, Paul Robertson, Mark R. Giovinazzi, Joseph M. Akana Murphy, Eric B. Ford, Samuel Halverson, Te Han, Rae Holcomb, Jack Lubin, Rafael Luque, Pranav P… 展开作者
Corey Beard, Paul Robertson, Mark R. Giovinazzi, Joseph M. Akana Murphy, Eric B. Ford, Samuel Halverson, Te Han, Rae Holcomb, Jack Lubin, Rafael Luque, Pranav Premnath, Chad F. Bender, Cullen H. Blake, Qian Gong, Howard Isaacson, Shubham Kanodia, Dan Li, Andrea S. J. Lin, 5 Sarah E. Logsdon, Emily Lubar, Michael W. McElwain, Andrew Monson, Joe P. Ninan, Jayadev Rajagopal, Arpita Roy, Christian Schwab, Gudmundur Stefansson, Ryan C. Terrien, Jason T. Wright
We present a new analysis of Kepler-21, the brightest (V = 8.5) Kepler system with a known transiting exoplanet, Kepler-21 b. Kepler-21 b is a radius valley planet ($R = 1.6\pm 0.2 R_{\oplus}$) with an Earth-like composition (8.38$\pm$1.62 g/cc), though its mass and radius fall in the regime of possible "water worlds." We utilize new Keck/HIRES and WIYN/NEID radial velocity (RV) data in conjunction with Kepler and TESS photometry to perform a detailed study of activity mitigation between photometry and RVs. We additionally refine the system parameters, and we utilize Gaia astrometry to place constraints on a long-term RV trend. Our activity analysis affirms the quality of Kepler photometry for removing correlated noise from RVs, despite its temporal distance, though we reveal some cases where TESS may be superior. Using refined orbital parameters and updated composition curves, we rule out a ``water world" scenario for Kepler-21 b, and we identify a long period super-Jupiter planetary candidate, Kepler-21 (c).
Probability of Physical Association of 104 Blended Companions to \textit{Kepler} Objects of Interest Using Visible and Near-Infrared Adaptive Optics Photometry
NASA's Kepler mission observed background regions across its field of view for more than three consecutive years using custom designed super apertures (EXBA masks). Since these apertures were designed to capture a region of the sky rather than single targets, the Kepler Science Data Processing pipeline produced Target Pixel Files, but did not produce light curves for the sources within these background regions. In this work we produce light curves for $9,327$ sources observed in the EXBA masks. These light curves are generated using aperture photometry estimated from the instrument's Pixel Res…
A consistent analysis of three years of ground- and space-based photometry of TrES-2
G 0 V矮星TrES-2A被一颗热木星穿过,是开普勒望远镜的主要短节奏目标之一,因此是当今已知的光度学研究最好的行星系之一。鉴于行星轨道的几何形状接近掠射,TrES-2为探索其轨道几何形状的变化提供了一个极好的机会。我们的研究重点是在以前的研究中报道的轨道倾角的长期变化。我们提出了一个联合分析的前四个季度的开普勒测光连同公开获得的地面数据,因为在2006年发现的TrES-2b。我们使用一个共同的方法,根据最新的信息,视觉同伴的TrES-2A和恒星临边变暗,以进一步完善轨道参数。我们发现开普勒观测排除了先前声称的长期倾角变化以及凌日时间的变化,然而,它们也显示出轻微的迹象,表明倾角的进一步变化仍然是微不足道的。
Kepler Mission's single-band photometry suffers from astrophysical false positives, the most common of background eclipsing binaries (BEBs) and companion transiting planets (CTPs). Multi-color photometry can reveal the color-dependent depth feature of false positives and thus exclude them. In this work, we aim to estimate the fraction of false positives that are unable to be classified by Kepler alone but can be identified with their color-dependent depth feature if a reference band (z, Ks and TESS) were adopted in follow-up observation. We build up physics-based blend models to simulate multi…
The Kepler mission has provided a wealth of data, revealing new insights in time-domain astronomy. However, Kepler's single band-pass has limited studies to a single wavelength. In this work we build a data-driven, pixel-level model for the Pixel Response Function (PRF) of Kepler targets, modeling the image data from the spacecraft. Our model is sufficiently flexible to capture known detector effects, such as non-linearity, intra-pixel sensitivity variations, and focus change. In theory, the shape of the Kepler PRF should also be weakly wavelength dependent, due to optical chromatic aberration…
Kepler 18-b, c, and d: A System Of Three Planets Confirmed by Transit Timing Variations, Lightcurve Validation, Spitzer Photometry and Radial Velocity Measurements
TRADES: A new software to derive orbital parameters from observed transit times and radial velocities. Revisiting Kepler-11 and Kepler-9
目的。为了从观测数据中确定系外行星系统的轨道参数,我们开发了一个名为TRADES(TRAnsits and Dynamics of Exoplanetary Systems)的软件,可以同时拟合观测到的径向速度和凌日时间数据。方法.我们实现了一个N体系统的动力学模拟器,它也适合在轨道集成过程中的可用数据,并确定最佳的轨道参数组合,使用网格搜索,$χ^2$最小化,遗传算法,粒子群优化,和引导分析。结果为了验证TRADES,我们在合成三体系统和开普勒任务发现的两个真实系统上测试了代码:开普勒-9和开普勒-11。这些系统是测试多个系外行星系统的良好基准,这些系统由于行星之间的引力相互作用而显示出过境时间变化(TTV)。我们发现开普勒-11行星的轨道参数与发现论文中提出的值以及同一作者最近的工作非常一致。我们分析了Kepler-9系统的前三个季度,发现与发现论文部分一致的参数。分析涵盖开普勒数据的12个季度的过境时间(T0),我们已经找到了一个新的最佳拟合解决方案。该解决方案输出的质量约为发现论文中提出的值的55%;这导致径向速度的半幅值降低约为12.80 m/s。
Precise Radial Velocity Measurements for Kepler Giants Hosting Planetary Candidates: Kepler-91 and KOI-1894
本文介绍了利用斯巴鲁8.2米望远镜和高色散摄谱仪(HDS)对两颗开普勒演化恒星Kepler-91(KOI-2133)和KOI-1894进行径向速度跟踪观测的结果,这两颗恒星被宣布为凌日巨行星的候选者。通过对Subaru/HDS拍摄的高精度径向速度数据和开普勒任务拍摄的测光数据进行全球建模,并考虑轨道亮度调制(椭球变化,反射/发射光等)。我们独立地确认了Kepler-91中有一颗质量为0.66 M_Jup的凌日行星(Kepler-91 b),并在~1年的时间间隔内观测到了~20 m s $^{-1}$的径向速度偏差,这表明该系统中还存在另外一颗伴星。对于KOI-1894,我们检测到径向速度和光变曲线可能的相位变化,置信度为2- 3 sigma,这可以解释为由过境的亚土星质量(~0.18 M_Jup)行星引起的恒星反射运动和椭球变化。
Planet-Planet Eclipse and the Rossiter-McLaughlin Effect of a Multiple Transiting System: Joint Analysis of the Subaru Spectroscopy and the Kepler Photometry
Determining the Mass of Kepler-78b With Nonparametric Gaussian Process Estimation
开普勒-78b是一颗凌日行星,半径是地球的1.2倍,每8小时绕一颗年轻的活跃K矮星运行一周。开普勒-78b的质量已经由两个团队独立地报告,基于使用HIRES和HARPS-N光谱仪的径向速度测量。由于主星的活动性质,需要一个恒星活动模型来区分和分离径向速度数据中的行星信号。而以前的研究测试参数恒星活动模型,我们模拟这个系统使用非参数高斯过程(GP)回归。我们对相关的开普勒测光进行了GP回归。然后,我们使用我们的光度拟合的后验参数分布作为我们的径向速度数据集的同步GP +开普勒轨道模型的先验。我们为GP回归测试了三个简单的核函数。基于贝叶斯似然分析,我们选择了一个准周期核模型与GP超参数耦合之间的两个RV数据集,给出了多普勒振幅为1.86 $\pm$ 0.25 m s $^{-1}$,并支持我们的信念,我们正在建模的相关噪声是天体物理。1.87 $^{+0.27}_{-0.26}$ M $_{\oplus}$的相应质量与先前研究中测量的质量一致,并且由于我们的非参数信号估计而更稳健。根据我们的质量和通过凌日光度法测量的半径,开普勒-78 b的体积密度为6.0 $^{+1.9}_{-1.4}$ g cm $^{-3}$。我们估计,开普勒-78 b是32 $\pm$ 26%的铁使用两个组件的岩石-铁模型。这与类地球的组成一致,不确定性跨越类月到类水星的组成。
SOPHIE velocimetry of Kepler transit candidates XVIII. Radial velocity confirmation, absolute masses and radii, and origin of the Kepler-419 multiplanetary system
The Kepler-19 system: a thick-envelope super-Earth with two Neptune-mass companions characterized using Radial Velocities and Transit Timing Variations
我们报告了开普勒-19系统的详细特征。这颗恒星之前被认为拥有一颗凌日行星,周期为9.29天,半径为2.2 R $_\oplus$,质量上限为20 M $_\oplus$。第二颗非凌日行星的存在是从开普勒-19 b的凌日时间变化(TTV)推断出来的,超过了开普勒测光的四分之八,尽管质量和周期都无法确定。通过结合来自所有开普勒四分之一的新TTV测量值和HARPS-N摄谱仪获得的91个高精度径向速度,我们通过动力学模拟测量了开普勒-19 b的质量为$8.4 \pm 1.6$ M $_\oplus$。根据同样的数据,假设系统共面,我们确定开普勒-19 c的轨道周期为28.7天,质量为$13.1 \pm 2.7$ M $_\oplus$,并发现了一颗质量为$20.3 \pm 3.4$ M $_\oplus$的类海王星行星,轨道为63天。通过比较动力学模拟与非相互作用的开普勒轨道,我们得出结论,忽略行星之间的相互作用可能会导致系统误差,这可能会妨碍在轨道参数的精度时,数据集跨越几年。密度为$4.32 \pm 0.87$ g cm $^{-3}$($0.78 \pm 0.16$ $ρ_\oplus$)开普勒-19 b属于岩石核心和大量挥发物的行星群,与低密度行星相反,低密度行星的特征是只有过境时间变化,以及越来越多的岩石行星具有类似地球的密度。开普勒-19加入了少数协调凌日时间变化和径向速度测量…
NASA's Kepler, K2 and TESS missions employ Simple Aperture Photometry (SAP) to derive time-series photometry, where an aperture is estimated for each star, and pixels containing each star are summed to create a single light curve. This method is simple, but in crowded fields the derived time-series can be highly contaminated. The alternate method of fitting a Point Spread Function (PSF) to the data is able to account for crowding, but is computationally expensive. In this paper, we present a new approach to extracting photometry from these time-series missions, which fits the PSF directly, but…
The radial velocity method is amongst the most robust and most established means of detecting exoplanets. Yet, it has so far failed to detect circumbinary planets despite their relatively high occurrence rates. Here, we report velocimetric measurements of Kepler-16A, obtained with the SOPHIE spectrograph, at the Observatoire de Haute-Provence's 193cm telescope, collected during the BEBOP survey for circumbinary planets. Our measurements mark the first radial velocity detection of a circumbinary planet, independently determining the mass of Kepler-16~(AB)~b to be $0.313 \pm 0.039\,{\rm M}_{\rm …
DELOS: Contrastive Deep Learning for Low-SNR Blind Transit Searches in Kepler Photometry
Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China(上海天文台,中国科学院,上海200030,中国);School of Astronomy and Space Sciences, University of Chinese Academy of Sciences, Beijing 101408, China(中国科学院大学天文与空间科学学院,北京101408,中国);Science Talent Training Center, Gainesville, FL, 32606 USA(科学人才培训中心,佛罗里达州盖恩斯维尔,32606 USA)
We present the latest and most precise characterization of the architecture for the ancient ($\approx 11$ Gyr) Kepler-444 system, which is composed of a K0 primary star (Kepler-444 A) hosting five transiting planets, and a tight M-type spectroscopic binary (Kepler-444 BC) with an A-BC projected separation of 66 au. We have measured the system's relative astrometry using the adaptive optics imaging from Keck/NIRC2 and Kepler-444 A's radial velocities from the Hobby Eberly Telescope, and re-analyzed relative radial velocities between BC and A from Keck/HIRES. We also include the Hipparcos-Gaia a…