We present a line-by-line differential analysis of a sample of 16 planet hosting stars and 68 comparison stars using high resolution, high signal-to-noise ratio spectra gathered using Keck. We obtained accurate stellar parameters and high-precision relative chemical abundances with average uncertainties in \teff, \logg, [Fe/H] and [X/H] of 15 K, 0.034 [cgs], 0.012 dex and 0.025 dex, respectively. For each planet host, we identify a set of comparison stars and examine the abundance differences (corrected for Galactic chemical evolution effect) as a function of the dust condensation temperature, \tcond, of the individual elements. While we confirm that the Sun exhibits a negative trend between abundance and \tcond, we also confirm that the remaining planet hosts exhibit a variety of abundance $-$ \tcond\ trends with no clear dependence upon age, metallicity or \teff. The diversity in the chemical compositions of planet hosting stars relative to their comparison stars could reflect the range of possible planet-induced effects present in these planet hosts, from the sequestration of rocky material (refractory poor), to the possible ingestion of planets (refractory rich). Other possible explanations include differences in the timescale, efficiency and degree of planet formation or inhomogeneous chemical evolution. Although we do not find an unambiguous chemical signature of planet formation among our sample, the high-precision chemical abundances of the host stars are essential for constraining the composition and structure of their exoplanets.
Chemical signatures of planetary systems in their host stars. Near-infrared spectroscopy of four planet-hosting wide binaries
Yonsei University（延世大学）；Chungnam National University（忠南国立大学）；Zentrum für Astronomie der Universität Heidelberg, Astronomisches Rechen-Institut（海德堡大学天文计算研究所）；Korea Astronomy and Space Science Institute（韩国天体宇宙科学研究所）
Understanding the distribution of angular momentum during the formation of planetary systems is a key topic in astrophysics. Data from the $\textit{Kepler}$ and $\textit{Gaia}$ missions allow to investigate whether stellar rotation is correlated with the presence of planets around Sun-like stars. Here, we perform a statistical analysis of the rotation period of 493 planet-hosting stars. These are matched to a control sample, without detected planets, with similar effective temperatures, masses, radii, metallicities, and ages. We find that planet-hosting stars rotate on average $1.63 \pm 0.40$ …
It is not yet fully understood how planet formation affects the properties of host stars, in or out of a cluster; however, abundance trends can help us understand these processes. We present a detailed chemical abundance analysis of six stars in Praesepe, a planet-hosting open cluster. Pr0201 is known to host a close-in (period of 4.4 days) giant planet (mass of 0.54$\rm M_{\rm{J}}$), while the other five cluster members in our sample (Pr0133, Pr0081, Pr0208, Pr0051, and Pr0076) have no detected planets according to RV measurements. Using high-resolution, high signal-to-noise echelle spectra o…
Magnetic Activity Cycles and Rotation in Planet-hosting and Non-hosting Solar-type Stars
CRAAG - Centre de Recherche en Astronomie, Astrophysique et Géophysique（CRAAG - 天文学、天体物理学和地球物理学研究中心）；INAF – Osservatorio Astrofisico di Torino（意大利国家天体物理研究所 - 都灵天文台）；Laboratoire d’Astrophysique de Bordeaux, Univ. Bordeaux, CNRS（波尔多天体物理学实验室，波尔多大学，法国国家科学研究中心）；Space sciences, Technologies and Astrophysics Research (STAR) Institute, Université de Liège（列日大学空间科学、技术与天体物理研究（STAR）研究所）
Tidal interaction between an exoplanet and its host star is a possible pathway to transfer angular momentum between the planetary orbit and the stellar spin. In cases where the planetary orbital period is shorter than the stellar rotation period, this may lead to angular momentum being transferred into the star's rotation, possibly counteracting the intrinsic stellar spin-down induced by magnetic braking. Observationally, detecting altered rotational states of single, cool field stars is challenging, as precise ages for such stars are rarely available. Here we present an empirical investigatio…
A major goal in the discovery and characterisation of exoplanets is to identify terrestrial-type worlds that are similar to (or otherwise distinct from) our Earth. Recent results have highlighted the importance of applying devolatilisation -- i.e. depletion of volatiles -- to the chemical composition of planet-hosting stars to constrain bulk composition and interiors of terrestrial-type exoplanets. In this work, we apply such an approach to a selected sample of 13 planet-hosting Sun-like stars, for which high-precision photospheric abundances have been determined in the first paper of the seri…
We present a catalog (status July 1, 2022) of triple and higher order systems identified containing exoplanets based on data from the literature, including various analyses. We explore statistical properties of the systems with focus on both the stars and the planets. So far, about 30 triple systems and one to three quadruple systems, including (mildly) controversial cases, have been found. The total number of planets is close to 40. All planet-hosting triple star systems are highly hierarchic, consisting of a quasi-binary complemented by a distant stellar component, which is in orbit about th…
Planet formation is often considered in the context of one circumstellar disk around one star. Yet stellar binary systems are ubiquitous, and thus a substantial fraction of all potential planets must form and evolve in more complex, dynamical environments. We present the results of a five-year astrometric monitoring campaign studying 45 binary star systems that host Kepler planet candidates. The planet-forming environments in these systems would have literally been shaped by the binary orbits that persist to the present day. Crucially, the mutual inclinations of star-planet orbits can only be …
AU Mic is a young, very active M dwarf star with a debris disk and at least one transiting Neptune-size planet. Here we present detailed analysis of the magnetic field of AU Mic based on previously unpublished high-resolution optical and near-infrared spectropolarimetric observations. We report a systematic detection of circular and linear polarization signatures in the stellar photospheric lines. Tentative Zeeman Doppler imaging modeling of the former data suggests a non-axisymmetric global field with a surface-averaged strength of about 90 G. At the same time, linear polarization observation…
Planets Around Solar Twins/Analogs (PASTA) III: Chemical Clock Relations in Planet-Hosting Solar Analogs
Tsung-Dao Lee Institute, School of Physics and Astronomy, & State Key Laboratory of Dark Matter Physics, Shanghai Jiao Tong University（上海交通大学李政道研究所、物理与天文学院及暗物质物理国家重点实验室）；Department of Astronomy, The Ohio State University（俄亥俄州立大学天文学系）；Center for Cosmology and AstroParticle Physics (CCAPP), The Ohio State University（俄亥俄州立大学宇宙学与粒子天体物理学中心）；Department of Astronomy, Tsinghua University（清华大学天文学系）；Institute for Astronomy, University of Hawai‘i（夏威夷大学天文学研究所）
Orbital Architectures of Planet-Hosting Binaries: I. Forming Five Small Planets in the Truncated Disk of Kepler-444A
我们目前的第一个结果，从我们的凯克计划调查的轨道结构的行星托管多恒星系统。开普勒-444是一个贫金属的三星系统，拥有五颗次地球大小的行星围绕主星（开普勒-444A）运行，以及一对空间未解析的M矮星（开普勒-444BC），投影距离为1.8”（66 AU）。我们结合我们的凯克/NIRC 2自适应光学天体测量与多历元凯克/HIRES RV的所有三颗恒星，以确定一个精确的轨道周围的BC对，鉴于其经验约束的质量。我们测量最小的天体测量运动（$1.0\pm0.6$ mas yr $^{-1}$，或$0.17\pm0.10$ km s $^{-1}$），但我们的RV揭示了显着的轨道速度（$1.7\pm0.2$ km s $^{-1}$）和加速度（$7.8\pm0.5$ m s $^{-1}$ yr $^{-1}$）。我们确定了一个高偏心恒星轨道（$e=0.864\pm0.023$），使紧M矮星对内的行星系统的$5.0^{+0.9}_{-1.0}$ AU。我们验证了该系统是动态稳定的，在其目前的配置，通过n体模拟。我们发现A $-$ BC轨道和行星轨道很可能是对齐的（98%），因为它们都有边缘上的轨道和不对齐引起行星的进动。我们的结论是，在行星形成的时期，恒星可能在它们目前的轨道上，在$\approx$ 2 AU处截断了原行星盘。这个被截断的圆盘可能已经严重耗尽了固体物质，从而形成了总的$\app…
As host to two accreting planets, PDS 70 provides a unique opportunity to probe the chemical complexity of atmosphere-forming material. We present ALMA Band 6 observations of the PDS~70 disk and report the first chemical inventory of the system. With a spatial resolution of 0.4''-0.5'' ($\sim$50 au), 12 species are detected, including CO isotopologues and formaldehyde, small hydrocarbons, HCN and HCO+ isotopologues, and S-bearing molecules. SO and CH3OH are not detected. All lines show a large cavity at the center of the disk, indicative of the deep gap carved by the massive planets. The radia…
Many binary companions to the central stars of planetary nebulae (PNe) are found to be inflated, perhaps indicating that accretion onto the central star might occur during the PN phase. The discovery of a handful of nova eruptions and supersoft X-ray sources inside PNe supports this hypothesis. In this paper, we investigate the impact that hosting a steadily-accreting WD would have on the properties and evolution of a PN. By pairing the published accreting nuclear-burning WD models with radiation transfer simulations, we extract the time evolution of the emission line spectra and ionization pr…
Am stars are often components of short-period binary systems, where tidal interactions would result in low rotational velocities and help to develop the chemical peculiarities observed. However, the origin of single Am stars and Am stars that belong to wide binary systems is unclear. There is very recent evidence of an Am star hosting a hot-brown dwarf likely synchronized and other possible Am stars hosting hot-Jupiter planets. We wonder if these hot-low mass companions could play a role in the development of an Am star, that is to say, if they could help to mitigate the "single Am" problem. W…
A radial velocity study by Donati et al. (2016) reported the detection of a close-in giant planet in a 4.93 d orbit around the ~2 Myr old weak-lined T Tauri star V830 Tau. Because of the stringent timescale constraints that a very young host star like V830 Tau would place on hot Jupiter formation models and inward migration mechanisms, independent confirmation of the planet's existence is needed but so far has not been obtained. We present new Chandra X-ray observations of V830 Tau. The Chandra observations in combination with previous XMM-Newton observations reveal strong variable X-ray emiss…
We summarize Hubble Space Telescope (HST) UV observations of the weak-lined T Tauri star (wTTS) PDS 70 obtained with the Space Telescope Imaging Spectrograph (STIS). These observations provide the first far-UV (FUV) and near-UV (NUV) spectra of PDS 70. Ground-based observations have so far revealed two formative giant planets orbiting in a wide gap in its circumstellar disk. Both the star and young planets are thought to still be accreting. The HST spectra provide new insight into physical conditions in the star's outer atmosphere and circumstellar environment. The spectra are dominated by chr…
The study of planet occurrence as a function of stellar mass is important for a better understanding of planet formation. Estimating stellar mass, especially in the red giant regime, is difficult. In particular, stellar masses of a sample of evolved planet-hosting stars based on spectroscopy and grid-based modelling have been put to question over the past decade with claims they were overestimated. Although efforts have been made in the past to reconcile this dispute using asteroseismology, results were inconclusive. In an attempt to resolve this controversy, we study four more evolved planet-…
JWST Exoplanetary Worlds and Elemental Survey (JEWELS) II: Condensation Temperature Trends and Galactic Chemical Evolution in JWST Planet-Hosting Stars
Tsung-Dao Lee Institute, School of Physics and Astronomy, & State Key Laboratory of Dark Matter Physics, Shanghai Jiao Tong University（上海交通大学物理与天文学院、汤川研究所、暗物质物理国家重点实验室）；Department of Physics, King’s College London（伦敦国王学院物理系）；Department of Astronomy, Tsinghua University（清华大学天文系）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）
Quantifying the composition of the material in protoplanetary disks is paramount to determining the potential for exoplanetary systems to produce and support habitable environments. A key complex organic molecule (COM) to detect is methanol (CH3OH). CH3OH primarily forms at low temperatures via the hydrogenation of CO ice on the surface of icy dust grains and is a necessary basis for the formation of more complex species like amino acids and proteins. We report the detection of CH3OH in a disk around a young, luminous A-type star HD100546. This disk is warm and therefore does not host a signif…
Planets Around Solar Twins/Analogs (PASTA) I.: High precision stellar chemical abundance for 17 planet-hosting stars and the condensation temperature trend
