Eyes on K2-3: A system of three likely sub-Neptunes characterized with HARPS-N and HARPS
M. Damasso, A. S. Bonomo, N. Astudillo-Defru, X. Bonfils, L. Malavolta, A. Sozzetti, E. Lopez, L. Zeng, R. D. Haywood, J. M. Irwin, A. Mortier, A. Vanderburg, J… 展开作者
M. Damasso, A. S. Bonomo, N. Astudillo-Defru, X. Bonfils, L. Malavolta, A. Sozzetti, E. Lopez, L. Zeng, R. D. Haywood, J. M. Irwin, A. Mortier, A. Vanderburg, J. Maldonado, A. F. Lanza, L. Affer, J. -M. Almenara, S. Benatti, K. Biazzo, A. Bignamini, F. Borsa, F. Bouchy, L. A. Buchhave, A. C. Cameron, I. Carleo, D. Charbonneau, R. Claudi, R. Cosentino, E. Covino, X. Delfosse, S. Desidera, L. Di Fabrizio, C. Dressing, M. Esposito, R. Fares, P. Figueira, A. F. M. Fiorenzano, T. Forveille, P. Giacobbe, E. González-Álvarez, R. Gratton, A. Harutyunyan, J. Asher Johnson, D. W. Latham, G. Leto, M. Lopez-Morales, C. Lovis, A. Maggio, L. Mancini, S. Masiero, M. Mayor, G. Micela, E. Molinari, F. Motalebi, F. Murgas, V. Nascimbeni, I. Pagano, F. Pepe, D. F. Phillips, G. Piotto, E. Poretti, M. Rainer, K. Rice, N. C. Santos, D. Sasselov, G. Scandariato, D. Ségransan, R. Smareglia, S. Udry, C. Watson, A. Wünsche
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14 pages, 15 figures, accepted for publication in A&A
M-dwarf stars are promising targets for identifying and characterizing potentially habitable planets. K2-3 is a nearby (45 pc), early-type M dwarf hosting three small transiting planets, the outermost of which orbits close to the inner edge of the stellar (optimistic) habitable zone. The K2-3 system is well suited for follow-up characterization studies aimed at determining accurate masses and bulk densities of the three planets. Using a total of 329 radial velocity measurements collected over 2.5 years with the HARPS-N and HARPS spectrographs and a proper treatment of the stellar activity signal, we aim to improve measurements of the masses and bulk densities of the K2-3 planets. We use our results to investigate the physical structure of the planets. We analyse radial velocity time series extracted with two independent pipelines by using Gaussian process regression. We adopt a quasi-periodic kernel to model the stellar magnetic activity jointly with the planetary signals. We use Monte Carlo simulations to investigate the robustness of our mass measurements of K2-3\,c and K2-3\,d, and to explore how additional high-cadence radial velocity observations might improve them. Despite the stellar activity component being the strongest signal present in the radial velocity time series, we are able to derive masses for both planet b ($M_{\rm b}=6.6\pm1.1$ $M_{\rm \oplus}$) and planet c ($M_{\rm c}=3.1^{+1.3}_{-1.2}$ $M_{\rm \oplus}$). The Doppler signal due to K2-3\,d remains undetected, likely because of its low amplitude compared to the radial velocity signal induced by the stellar activity. The closeness of the orbital period of K2-3\,d to the stellar rotation period could also make the detection of the planetary signal complicated. [...]
The HARPS search for southern extrasolar planets: XXXIII. New multi-planet systems in the HARPS volume limited sample: a super-Earth and a Neptune in the habitable zone
The HARPS search for southern extra-solar planets. XXIV. Companions to HD 85390, HD 90156 and HD 103197: A Neptune analogue and two intermediate mass planets
K2-263b: A 50-day period sub-Neptune with a mass measurement using HARPS-N
本文报道了K2- 263 b的验证和质量测量，K2- 263 b是一颗围绕安静的G9 V星运行的亚海王星恒星。使用C5和C16战役的K2数据，我们发现这颗行星的周期为$50.818947\pm 0.000094$天，半径为$2.41\pm0.12$ R $_{\oplus}$。我们用HARPS-N跟踪这个系统，获得了67个精确的径向速度。通过对凌日和径向速度数据的综合拟合，发现K2- 263 b的质量为$14.8\pm3.1$ M $_{\oplus}$。它的体积密度（$5.7_{-1.4}^{+1.6}$ g cm $^{-3}$）意味着这颗行星在岩石核心周围有大量的水或其他挥发物。EPIC 211682544 b的形成方式可能与我们太阳系中四颗巨行星的核心相似，但由于某种原因，没有吸积太多气体。行星的质量是由一个独立的高斯过程为基础的适合径向速度和光谱活动指标。K2- 263 b属于少数已确认的K2系外行星，周期超过40天。对于一个小行星来说，它是最长的周期之一，它的质量是用径向速度精确确定的。
Confirmation of the hot super-Neptune TOI-672 b with NIRPS and HARPS and Insights into the Neptunian desert around M dwarfs
Univ. Grenoble Alpes（格勒诺布尔阿尔卑斯大学）；CNRS（法国国家科学研究中心）；McMaster University（麦克马斯特大学）；The University of Warwick（华威大学）；Observatoire de Genève, Département d’Astronomie, Université de Genève（日内瓦大学天文学系天文台）；Institut Trottier de recherche sur les exoplanètes（特罗蒂埃系外行星研究所）
The GAPS Programme at TNG LXXIV. A reanalysis of the planetary systems TOI-1272 and TOI-1694 with HARPS-N and retraction of the planetary interpretation of TOI-1272 c
University of Rome “Tor Vergata”（罗马托尔维加塔大学）；INAF – Turin Astrophysical Observatory（意大利国家天体物理研究所都灵天文台）；INAF – Astronomical Observatory of Rome（意大利国家天体物理研究所罗马天文台）；INAF – Astrophysical Observatory of Catania（意大利国家天体物理研究所卡塔尼亚天文台）；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CSIC-INTA））；Fundacion Galileo Galilei（伽利略基金会）；INAF – Astronomical Observatory of Trieste（意大利国家天体物理研究所的里雅斯特天文台）
The HARPS search for southern extra-solar planets XLV. Two Neptune mass planets orbiting HD 13808: a study of stellar activity modelling's impact on planet detection
Origin and characterization of super-Earths and sub-Neptunes
Observatoire de Genève, Université de Genève（日内瓦天文台，日内瓦大学）；Department of Astrophysics, University of Zurich（苏黎世大学天体物理系）；Institute for Particle Physics and Astrophysics, ETH Zürich（苏黎世联邦理工学院粒子物理与天体物理学研究所）；Center for Space and Habitability (CSH), Universität Bern（伯尔尼大学太空与宜居性中心）；Space Research and Planetary Sciences, Physics Institute, University of Bern（伯尔尼大学物理研究所空间研究与行星科学部门）；Institute of Geochemistry and Petrology（地球化学与岩石学研究所）；Centre for Star and Planet Formation, Globe Institute, University of Copenhagen（哥本哈根大学全球学院恒星与行星形成中心）
The HARPS search for southern extra-solar planets. XLVII. Five Jupiter-mass planets in long-period orbits, one highly irradiated Neptune, one brown dwarf, and five stellar binaries
The HARPS search for southern extra-solar planets. XXXVIII. Bayesian re-analysis of three systems. New super-Earths, unconfirmed signals, and magnetic cycles
Fast Rise of "Neptune-Size" Planets ($4-8 R_{\rm Earth}$) from $P\sim10$ to $\sim250$ days -- Statistics of Kepler Planet Candidates Up to $\sim 0.75 {\rm AU}$
The Hot Neptune Initiative (HONEI) III. An ultra-hot super Neptune orbiting the metal-rich subgiant star TOI-5646: the largest host for a desert dweller
University of Rome “Tor Vergata”（罗马第二大学）；INAF – Turin Astrophysical Observatory（意大利国家天体物理研究所都灵天文台）；Space Research Institute, Austrian Academy of Sciences（奥地利科学院空间研究所）；University of Bern（伯尔尼大学）；Leiden University（莱顿大学）；INAF – Astronomical Observatory of Rome（意大利国家天体物理研究所罗马天文台）
Exoplanet characterisation in the longest known resonant chain: the K2-138 system seen by HARPS
在多个星系中探测到低质量凌日系外行星，给行星形成和演化过程带来了新的约束，对现有的行星形成理论提出了挑战。然而，开普勒和K2探测到的小行星中只有一小部分有精确的质量测量，这是强制性的，以限制它们的组成。我们的目标是找到围绕相对明亮的恒星K2-138运行的行星。这个系统在动力学上是特别的，因为它呈现了迄今为止已知的最长的行星链，接近3：2共振。我们获得了215个HARPS谱，从中我们推导出K2-138的径向速度变化。通过对K2测光和HARPS径向速度（RV）的联合贝叶斯分析，我们约束了轨道上六颗行星的参数。四颗内行星的质量从b到e分别为3.1、6.3、7.9和13.0 $\mathrm{M}_{\oplus}$，精确度分别为34%、20%、18%和15%。体积密度分别为4.9、2.8、3.2和1.8 g cm $^{-3}$，范围从地球到海王星般的值。对于行星f和g，我们报告上限。最后，我们预测过境时间的变化，从群众派生的订单2至6分钟。鉴于其独特的动力学，K2-138是从太空进行过境时间变化（TTV）测量的理想目标，即将推出的CHEOPS（Characterizing ExOPlanet Satellite）可以研究这个高度密集的系统并比较TTV和RV质量。
The GAPS Programme at TNG. LXXIII. Confirmation of the hot sub-Neptune TOI-4602 b (HD 25295 b), a key target for future atmospheric characterization
INAF – Osservatorio Astronomico di Palermo（意大利国家天体物理研究所巴勒莫天文台）；ESO - European Southern Observatory（欧洲南方天文台）；INAF-Osservatorio Astronomico di Roma（意大利国家天体物理研究所罗马天文台）；INAF – Osservatorio Astrofisico di Catania（意大利国家天体物理研究所卡塔尼亚天文台）；Institute for Particle Physics and Astrophysics, ETH Zürich（苏黎世联邦理工学院粒子物理与天体物理研究所）；Space Research Institute, Austrian Academy of Sciences（奥地利科学院空间研究所）
The HARPS search for southern extra-solar planets. XXVII. Up to seven planets orbiting HD 10180: probing the architecture of low-mass planetary systems
