For the past 3 years we have been monitoring 62 K giant stars using precise stellar radial velocity (RV) measurements with the 2m Alfred Jensch telescope of the Thüringer Landessternwarte Tautenburg (TLS). To probe the dependence of planet formation on stellar mass by finding planets around intermediate-mass giant stars. We present high accuracy RV measurements of the K1.5 III star 42 Dra and the K4 III star HD 139357. The wavelength reference for the RV measurements was provided by an iodine absorption cell placed in the optical path of the spectrograph. Our measurements reveal that the time series of the radial velocity of 42 Dra shows a periodic variation of 479.1 days. HD 139357 shows periodic RV variations of 1125.7 days. Keplerian motion is the most likely explanation for the observed radial velocity variations for these stars. Thus the K giant stars 42 Dra and HD 139357 host extrasolar planets.
Uninterrupted observations from space-borne telescopes provide the photometric precision that is required to detect shallow transits of small planets missed by ground-based surveys. We used data from the Transiting Exoplanet Survey Satellite (TESS) to search for nearby planetary companions in 12 planetary systems with hot Jupiters: HD 2685, Qatar-10, WASP-4, WASP-48, WASP-58, WASP-91, WASP-120, WASP-121, WASP-122, WASP-140, XO-6, and XO-7. We also applied the transit timing method based on homogeneously determined mid-transit times in order to search for non-transiting companions that could gr…
We constrain the angular momentum architecture of HD 106906, a 13 $\pm$ 2 Myr old system in the ScoCen complex composed of a compact central binary, a widely separated planetary-mass tertiary HD 106906 b, and a debris disk nested between the binary and tertiary orbital planes. We measure the orientations of three vectors: the companion spin axis, companion orbit normal, and disk normal. Using near-IR high-resolution spectra from Gemini/IGRINS, we obtain a projected rotational velocity of $v\sin{i_p}$ = 9.5 $\pm$ 0.2 km/s for HD 106906 b. This measurement together with a published photometric r…
We study the excitation of mutual inclination between planetary orbits by a novel secular-orbital resonance in multiplanet systems perturbed by binary companions which we call "ivection". The ivection resonance happens when the nodal precession rate of the planet matches a multiple of the orbital frequency of the binary, and its physical nature is similar to the previously-studied evection resonance. Capture into an ivection resonance requires encountering the resonance with slowly increasing nodal precession rate, and it can excite the mutual inclination of the planets without affecting their…
The Impact of Stellar Multiplicity on Planetary Systems, I.: The Ruinous Influence of Close Binary Companions
预计双星伴星的动力学影响将深刻影响行星系。然而，在双星系统中识别行星的困难使得这种影响的大小不确定;尽管它们的形成和生存存在许多理论障碍，但至少有一些双星系统显然拥有行星。我们提出了高分辨率成像的382开普勒感兴趣的对象（KOIs）使用自适应光学成像和非冗余孔径掩模干涉测量（NRM）的Spark-II望远镜。在KOIs的506个候选双星伴星的完整样本中，我们将一些双星系统超分辨到<5 AU的投影分离，表明行星可能在这些动态活跃的环境中形成。然而，我们的行星宿主样本的预测分离的完整分布更广泛地揭示了太阳系尺度上的二元伴侣的严重缺乏。对于一个场双星总体，我们应该找到58个投影间隔ρ 0.4的双星伴星< 50 AU and mass ratio q >，但我们只找到了23个伴星（4.6 σ的赤字），其中许多伴星必须是投影接近的较宽的对。当用半长轴截断值a_cut和截断值S_bin内的抑制因子来参数化双星星族时，我们发现在a_cut = 47 + 59/-23 AU内，双星系统中的行星出现率仅为更宽双星或单星的S_bin = 0.34 + 0.14/-0.15倍。我们的结果表明，由于联星伴星的影响，银河系中五分之一的太阳型恒星不允许承载行星系。
The Possible Astrometric Signature of a Planetary-mass Companion to the Nearby Young Star TW Piscis Austrini (Fomalhaut B): Constraints from Astrometry, Radial Velocities, and Direct Imaging
我们目前的限制存在的亚恒星同伴附近（$d\sim7.6$ pc），年轻的（$440\pm40$百万年）K4 Ve星TW双鱼座Australini，宽（$\sim$ 0.3 pc）同伴A4 V星北落师门。我们将依巴谷和盖亚的绝对天体测量与文献径向速度测量和Keck/NIRC 2获得的专用高对比度成像观测相结合，以实现对数十年轨道周期（$\lesssim 10^3$ yr）的棕矮星和行星质量伴星（$\gtrsim2$ M $_{\rm Jup}$）的灵敏度。在依巴谷星表和盖亚星表之间测得的显著天体测量加速度，以前在文献中报道过，不能用TW PsA围绕北落师门三重系统重心的轨道运动来解释。相反，我们发现它是一致的反射运动引起的轨道亚恒星的同伴。天体测量、径向速度和深$L^{\prime}$成像数据集的组合导致对$1.2_{-0.6}^{+0.7}$ M $_{\rm Jup}$的伴星质量的限制。然而，伴星的周期受到很差的约束，由于依巴谷和盖亚之间的24.25年基线混叠，因此具有高度多模态的周期后验分布。如果通过持续的天体测量或光谱监测，或通过直接探测得到证实，TW PsA的伴星将成为即将到来的詹姆斯韦伯太空望远镜和宽视场红外巡天望远镜上使用高对比度仪器进行详细大气特征描述的首选目标。
The first discovered extrasolar worlds -- giant, ``hot Jupiter'' planets on short-period orbits -- came as a surprise to solar-system-centric models of planet formation, prompting the development of new theories for planetary system evolution. The near-absence of observed nearby planetary companions to hot Jupiters has been widely quoted as evidence in support of high-eccentricity tidal migration: a framework in which hot Jupiters form further out in their natal protoplanetary disks before being thrown inward with extremely high eccentricities, stripping systems of any close-in planetary compa…
Hot Jupiters are generally observed to lack close planetary companions, a trend that has been interpreted as evidence for high-eccentricity migration. We present the discovery and validation of WASP-132 c (TOI-822.02), a 1.85 $\pm$ 0.10 $R_{\oplus}$ planet on a 1.01 day orbit interior to the hot Jupiter WASP-132 b. Transiting Exoplanet Survey Satellite (TESS) and ground-based follow-up observations, in conjunction with vetting and validation analysis, enable us to rule out common astrophysical false positives and validate the observed transit signal produced by WASP-132 c as a planet. Running …
Discovery of Rotational Modulations in the Planetary-Mass Companion 2M1207b: Intermediate Rotation Period and Heterogeneous Clouds in a Low Gravity Atmosphere
Aims. We report the detection of long-period radial velocity (RV) variations in three giant stars, HD 19615, HD 150010, and HD 174205, using precise RV measurements. Methods. These detections are part of the Search for Exoplanets around Northern Circumpolar Stars (SENS) survey being conducted at the Bohyunsan Optical Astronomy Observatory (BOAO). The nature of the RV variations was investigated by analyzing the photometric and line shape variations. We found no variability with the RV period in these quantities and conclude that the RV variations are most likely caused by planetary companions.…
Tracking Advanced Planetary Systems (TAPAS) with HARPS-N. III. HD 5583 and BD+15 2375 - two cool giants with warm companions
演化恒星是理解行星形成机制对恒星质量的依赖性和深入探索恒星-行星相互作用机制的关键。在过去的十年中，我们已经监测了大约1000颗进化恒星的径向速度变化，以寻找宾夕法尼亚州立大学-托伦天文学行星搜索中心的Hobby-Eberly望远镜下的低质量同伴。根据TAPAS项目，在3.6米国家伽利略望远镜上使用HARPS-N跟踪了需要更高RV精度测量的选定潜在候选者。我们的目标是探测演化恒星周围的行星系，以便能够对这些系统的频率和内在性质进行合理的统计，并对选定的行星系进行深入研究，并提供恒星-行星相互作用过程的证据。对于HD 5583，我们使用Hobby-Eberly望远镜（HET）在2313天内收集了14个时期的精确RV测量数据，并在976天内收集了22个时期的超精确HARPS-N数据。对于BD+15 2375，我们收集了超过3286天的24个HET数据和超过902天的25个HARPS-S数据。我们报告发现了两个行星质量物体绕两颗演化的红巨星运行：HD~5583在0.529天文单位处有一个近圆轨道的伴星，它的轨道半径为5.78 M，轨道半径为$_{J}$（e=0.076），是用RV技术探测到的一颗巨星最近的伴星，BD+15~2735，它的m sin i= 1.06 M $_{J}$保持着迄今为止发现的最轻行星绕演化恒星运行的记录（在圆e=0.001，0.576 AU的轨道上）。这是TAPA…
Planetary Architectures of Kepler Compact Multis with Binary Star Companions
University of California Santa Cruz（加州大学圣克鲁兹分校）；Mullard Space Science Laboratory, University College London（伦敦大学学院穆拉德空间科学实验室）；California Institute of Technology（加州理工学院）
Transiting Planetary Systems with Distant Giant Companions Remain Moderately Coplanar
State Key Laboratory of Dark Matter Physics, Tsung-Dao Lee Institute & School of Physics and Astronomy, Shanghai Jiao Tong University（暗物质物理国家重点实验室，李政道理论与计算科学中心及物理与天文学院，上海交通大学）；CAS Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences（中国科学院光学天文重点实验室，国家天文台，中国科学院）；Institute for Astronomy, University of Hawai‘i（夏威夷大学天体物理研究所）
We present the results of a uniform search for additional planets around all stars with confirmed hot Jupiters observed by the Transiting Exoplanet Survey Satellite (TESS) in its Cycle 1 survey of the southern ecliptic hemisphere. Our search comprises 184 total planetary systems with confirmed hot Jupiters with $R_{p}$ > 8$R_\oplus$ and orbital period < 10 days. The Transit Least Squares (TLS) algorithm was utilized to search for periodic signals that may have been missed by other planet search pipelines. While we recovered 169 of these confirmed hot Jupiters, our search yielded no new statist…
Planets Around Low-Mass Stars (PALMS). VI. Discovery of a Remarkably Red Planetary-Mass Companion to the AB Dor Moving Group Candidate 2MASS J22362452+4751425
Retired A Stars and Their Companions VIII: 15 New Planetary Signals Around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts
我们在亚巨星周围发现了7颗新行星和8颗候选行星，作为对已知的“退休A星”周围行星样本的补充（Johnson et al. 2006）。其中可能是第一个围绕次巨星的三行星系统，HD 163607和HD 4917。此外，我们还计算了所有已知行星围绕亚巨星（3 < log g < 4）恒星的可能过境时间、持续时间、深度和概率，重点是TESS任务期间可能的过境。虽然大多数行星的过境概率为1- 2%，但我们发现有3颗行星的过境概率> 9%。
In this paper, we determine the detectability of eclipsing binary star companions from eclipse timing variations using the Kepler mission dataset. Extensive and precise stellar time-series photometry from space-based missions enable searches for binary star companions. However, due to the large datasets and computational resources involved, these searches would benefit from guidance from detection simulations. Our simulations start with and benefit from the use of empirical Kepler mission data, into which we inject third bodies to predict the resulting timing of binary star eclipses. We find t…
Because of the diversity of stellar masses and orbital sizes of binary systems, and the complex interaction between star-star, star-planet and planet-planet, it has been difficult to fully characterize the planetary systems associated with binary systems. Here, we report high-precision astrometric observations of the low-mass binary system GJ 896AB, revealing the presence of a Jupiter-like planetary companion (GJ 896Ab). The planetary companion is associated to the main star GJ 896A, with an estimated mass of 2.3 Jupiter masses and an orbit period of 284.4 days. A simultaneous analysis of the …
The atmospheres and accretion disks of planetary-mass and substellar companions provide an unprecedented look into planet and moon formation processes, most notably the frequency and lifetime of circumplanetary disks. In our ongoing effort to leverage the extraordinary sensitivity of the Spitzer/Infrared Array Camera (IRAC) at 3.6, 4.5, 5.8, and 8.0 $μ$m to study wide planetary-mass and substellar companions near the diffraction limit, we present point-spread function (PSF) fitting photometry of archival Spitzer/IRAC images for nine stars (G0 to M4+M7) in nearby star-forming regions or stellar…
Kernel phase is a method to interpret stellar point source images by considering their formation as the analytical result of an interferometric process. Using Fourier formalism, this method allows for observing planetary companions around nearby stars at separations down to half a telescope resolution element, typically 20\,mas for a 8\,m class telescope in H band. The Kernel-phase analysis has so far been mainly focused on working with a single monochromatic light image, recently providing theoretical contrast detection limits down to $10^{-4}$ at 200\,mas with JWST/NIRISS in the mid-infrared…
Origins of giant planets on tight orbits, so called hot Jupiters, are a long-lasting question in the planetary formation and evolution theory. The answer seems to be hidden in architectures of those systems that remain only partially understood. Using multi-sector time-series photometry from the Transiting Exoplanet Survey Satellite, we searched for additional planets in the KELT-18, KELT-23, KELT-24, Qatar-8, WASP-62, WASP-100, WASP-119, and WASP-126 planetary systems using both the transit technique and transit timing method. Our homogenous analysis has eliminated the presence of transiting …
We have been conducting a exoplanet search survey using Bohyunsan Observatory Echelle Spectrograph (BOES) for the last 18 years. We present the detection of exoplanet candidate in orbit around HD 18438 from high-precision radial velocity (RV) mesurements. The target was already reported in 2018 (Bang et al. 2018). They conclude that the RV variations with a period of 719 days are likely to be caused by the pulsations because the Lomb-Scargle periodogram of HIPPARCOS photometric and Ha EW variations for HD 18438 show peaks with periods close to that of RV variations and there were no correlatio…
