POSEIDON II: The Anti-Aligned Orbit of the Warm Neptune TOI-1710 A b
Princeton University（普林斯顿大学）；Indiana University（印第安纳大学）；Universidad Adolfo Ibáñez（阿道夫·伊巴涅斯大学）；Schmidt Sciences（施密特科学）；University of Amsterdam（阿姆斯特丹大学）
Juan I. Espinoza-Retamal, Hareesh Bhaskar, Joshua N. Winn, Cristobal Petrovich, Rafael Brahm, Caleb Lammers, Guðmundur Stefánsson, Elise Koo, Andrés Jordán, Felipe I. Rojas
备注：
11 pages, 3 figures. Accepted for publication in ApJ Letters
We present an observation of the Rossiter-McLaughlin effect for the TOI-1710 system with the NEID spectrograph on the WIYN 3.5 m telescope. The system hosts a warm Neptune ($P\sim24$ days), and our observations reveal that it orbits in the opposite direction to the stellar spin, with a sky-projected obliquity $λ=179\pm19^{\circ}$. Combined with information about the rotation period of the host star, we measure a true obliquity $ψ=158_{-13}^{+11}\,^{\circ}$. The host star has an M-dwarf companion at a separation of $\sim3600$ au, but this companion is too distant to be solely responsible for misaligning the warm Neptune. The host star also shows a long-term radial velocity trend, indicative of a companion at intermediate separations. We show that such a companion can dynamically couple the warm Neptune to the distant M dwarf, enabling the transfer of inclination from the wide binary orbit to the planetary orbit. Assuming this scenario is correct, we predict the intermediate companion is a $\sim5\,M_J$ planet on a $\sim15$ au orbit that is nearly aligned with the transiting planet's orbit.
The Kepler and TESS missions revealed a remarkable abundance of sub-Neptune exoplanets. Despite this abundance, our understanding of the nature and compositional diversity of sub-Neptunes remains limited, to a large part because atmospheric studies via transmission spectroscopy almost exclusively aimed for low-density sub-Neptunes and even those were often affected by high-altitude clouds. The recent TESS discovery of the hot, dense TOI-824b ($2.93\,R_\oplus$ and $18.47\,M_\oplus$) opens a new window into sub-Neptune science by enabling the study of a dense sub-Neptune via secondary eclipses. …
Mapping the orbital obliquity distribution of young planets is one avenue towards understanding mechanisms that sculpt the architectures of planetary systems. TOI-942 is a young field star, with an age of ~60 Myr, hosting a planetary system consisting of two transiting Neptune-sized planets in 4.3- and 10.1-day period orbits. We observed the spectroscopic transits of the inner Neptune TOI-942b to determine its projected orbital obliquity angle. Through two partial transits, we find the planet to be in a prograde orbit, with a projected obliquity angle of |lambda| = 1/+41-33 deg. In addition, i…
POSEIDON III: The Aligned Orbit of the Hot Neptune Around the Hot Star WASP-195
Princeton University（普林斯顿大学）；Universidad Adolfo Ibáñez（阿道夫·伊瓦涅斯大学）；California Institute of Technology（加州理工学院）；University of Amsterdam（阿姆斯特丹大学）；ASTRON, Netherlands Institute for Radio Astronomy（荷兰射电天文研究所（ASTRON））
We investigate the potential for the James Webb Space Telescope (JWST) to detect and characterize the atmospheres of the sub-Neptunian exoplanets in the TOI-270 system. Sub-Neptunes are considered more likely to be water worlds than gas dwarfs. We model their atmospheres using three atmospheric compositions - two examples of hydrogen-dominated atmospheres and a water-dominated atmosphere. We then simulate the infrared transmission spectra of these atmospheres for JWST instrument modes optimized for transit observation of exoplanet atmospheres : NIRISS, NIRSpec and MIRI. We then predict the obs…
We investigate the exoplanet candidate TOI-1422b, which was discovered by the TESS space telescope around the high proper-motion G2V star TOI-1422 ($V=10.6$ mag), 155pc away, with the primary goal of confirming its planetary nature and characterising its properties. We monitored TOI-1422 with the HARPS-N spectrograph for 1.5 years to precisely quantify its radial velocity variation. The radial velocity measurements are analyzed jointly with TESS photometry and we also check for blended companions through high-spatial resolution images using the AstraLux instrument. We estimate that the parent …
Sibling Sub-Neptunes Around Sibling M Dwarfs: TOI-521 and TOI-912
Instituto de Astrofísica de Canarias (IAC)（加那利群岛天体物理研究所）；Universidad de La Laguna (ULL)（拉古纳大学）；Instituto de Astrofísica de Andalucía (IAA-CSIC)（安达卢西亚天体物理研究所）；Hitotsubashi University（一桥大学）；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究所）；Institut de Ciències de l’Espai (ICE, CSIC)（空间科学研究所）；Centro de Astrobiología (CSIC-INTA)（天体生物学中心）；Univ. Grenoble Alpes（格勒诺布尔阿尔卑斯大学）；Institute of Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicu（尼古拉·哥白尼大学天文系，物理、天文与信息学院）
TOI-3862 b: A dense super-Neptune deep in the hot Neptune desert
INAF – Osservatorio Astrofisico di Torino（意大利国家天体物理研究所都灵天文台）；Instituto de Astrofísica de Canarias (IAC)（加那利群岛天体物理研究所）；Astronomical Observatory, University of Geneva（日内瓦大学天文台）；Departamento de Astrofísica, Universidad de La Laguna (ULL)（拉帕尔马大学天体物理学系）；Institute of Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University（尼古拉斯·哥白尼大学物理、天文和信息学院天文学研究所）
Spin-Orbit Alignment of Two Neptune-size Planets Younger than 500 Myr: TOI-560 b and TOI-5082 b
Institute for Astronomy, University of Hawaii（夏威夷大学天文研究所）；Department of Astronomy, California Institute of Technology（加州理工学院天文学系）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；Department of Astronomy, University of California Berkeley（加州大学伯克利分校天文学系）；Center for Computational Astrophysics, Flatiron Institute（西蒙斯基金会平顿研究所计算天体物理中心）；Korea Astronomy and Space Science Institute（韩国天文与空间科学研究院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Department of Astronomy, Indiana University（印第安纳大学天文学系）
Transmission Spectrum of the Benchmark Temperate Exo-Neptune TOI-1231 b
School of Physics and Astronomy, Cardiff University（卡迪夫大学物理与天文学学院）；Institute of Astronomy, University of Cambridge（剑桥大学天文研究所）；Space Telescope Science Institute（太空望远镜科学研究所）；Space Science Institute（空间科学研究所）
We present the validation of two planets orbiting M dwarfs, TOI-1696b and TOI-2136b. Both planets are mini-Neptunes orbiting nearby stars, making them promising prospects for atmospheric characterization with the James Webb Space Telescope. We validated the planetary nature of both candidates using high contrast imaging, ground-based photometry, and near-infrared radial velocities. Adaptive Optics images were taken using the ShARCS camera on the 3 m Shane Telescope. Speckle images were taken using the NN-Explore Exoplanet Stellar Speckle Imager on the WIYN 3.5 m telescope. Radii and orbital ep…
JWST NIRSpec G395H Transmission Spectra of Two Similar Sub-Neptunes in the TOI-125 System
Johns Hopkins University（约翰斯·霍普金斯大学）；Space Telescope Science Institute（太空望远镜科学研究所）；University of Oxford（牛津大学）；Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE, UK（剑桥大学卡文迪许实验室）；University of California San Diego（加利福尼亚大学圣地亚哥分校）
TOI-2076 b is a sub-Neptune-sized planet ($R= 2.39 \pm 0.10 {R_\oplus}$) that transits a young ($204 \pm 50 {MYr}$) bright ($V = 9.2$) K-dwarf hosting a system of three transiting planets. Using spectroscopic observations with the NEID spectrograph on the WIYN 3.5 m Telescope, we model the Rossiter-McLaughlin effect of TOI-2076 b, and derive a sky-projected obliquity of $λ=-3_{-15}^{+16\:\circ}$. Using the size of the star ($R=0.775 \pm0.015 {R_\odot}$), and the stellar rotation period ($P_{\mathrm{rot}}=7.27\pm0.23$ days), we estimate an obliquity of $ψ=18_{-9}^{+10\:\circ}$ ($ψ< 34^\circ$ at…
TOI-270d is a temperate sub-Neptune discovered by the Transiting Exoplanet Survey Satellite (TESS) around a bright (J=9.1mag) M3V host star. With an approximate radius of 2RE and equilibrium temperature of 350K, TOI-270d is one of the most promising small exoplanets for atmospheric characterisation using transit spectroscopy. Here we present a primary transit observation of TOI-270d made with the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) spectrograph across the 1.126-1.644 micron wavelength range, and a 95% credible upper limit of $8.2 \times 10^{-14}$ erg s$^{-1}$ cm$^{-2}$ A$^{…
We report observations of the recently discovered warm Neptune TOI-674 b (5.25 \rearth{}, 23.6 \mearth{}) with the Hubble Space Telescope's Wide Field Camera 3 instrument. TOI-674 b is in the Neptune desert, an observed paucity of Neptune-size exoplanets at short orbital periods. Planets in the desert are thought to have complex evolutionary histories due to photoevaporative mass loss or orbital migration, making identifying the constituents of their atmospheres critical to understanding their origins. We obtained near-infrared transmission spectroscopy of the planet's atmosphere with the G141…
Densities of small planets around the M dwarfs TOI-4336 A and TOI-4342 with ESPRESSO: Three sub-Neptunes, one super-Earth, and a Neptune-mass candidate
Observatoire de Genève, Département d’Astronomie, Université de Genève（日内瓦天文台，天文学系，日内瓦大学）；Institut Trottier de recherche sur les exoplanètes, Département de Physique, Université de Montréal（特罗蒂埃系外行星研究所，物理系，蒙特利尔大学）；Institute for Particle Physics and Astrophysics, ETH Zürich（粒子物理学与天体物理学研究所，苏黎世联邦理工学院）；Centro de Astrobiología (CAB), CSIC-INTA（天体生物学中心（CAB），西班牙国家研究委员会-国家航空航天技术研究所）；Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP（天体物理学与空间科学研究所，波尔图大学，CAUP）；Departamento de Matemática y Física Aplicadas, Universidad Católica de la Santísima Concepción（应用数学与物理系，天主教神圣启示大学）；Univ. Grenoble Alpes, CNRS, IPAG（格勒诺布尔阿尔卑斯大学，法国国家科学研究中心，IPAG）；Department of Physics and Astronomy, McMaster University（物理与天文学系，麦克马斯特大学）；Center for Astrophysics | Harvard & Smithsonian（天体物理中心，哈佛大学与史密森尼学会）
TOI-216 hosts a pair of warm, large exoplanets discovered by the TESS Mission. These planets were found to be in or near the 2:1 resonance, and both of them exhibit transit timing variations (TTVs). Precise characterization of the planets' masses and radii, orbital properties, and resonant behavior can test theories for the origins of planets orbiting close to their stars. Previous characterization of the system using the first six sectors of TESS data suffered from a degeneracy between planet mass and orbital eccentricity. Radial velocity measurements using HARPS, FEROS, and PFS break that de…
We report the discovery of an eccentric hot Neptune and a non-transiting outer planet around TOI-1272. We identified the eccentricity of the inner planet, with an orbital period of 3.3 d and $R_{\rm p,b} = 4.1 \pm 0.2$ $R_\oplus$, based on a mismatch between the observed transit duration and the expected duration for a circular orbit. Using ground-based radial velocity measurements from the HIRES instrument at the Keck Observatory, we measured the mass of TOI-1272b to be $M_{\rm p,b} = 25 \pm 2$ $M_\oplus$. We also confirmed a high eccentricity of $e_b = 0.34 \pm 0.06$, placing TOI-1272b among…
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）
A Pair of Dynamically Interacting Sub-Neptunes Around TOI-6054
University of Wisconsin–Madison（威斯康星大学麦迪逊分校）；University of Kansas（堪萨斯大学）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；University of California, Irvine（加州大学尔湾分校）；Center for Astrophysics | Harvard & Smithsonian（哈佛与史密森尼天体物理中心）；NASA Exoplanet Science Institute-Caltech/IPAC（NASA系外行星科学研究所-加州理工/IPAC）；Sternberg Astronomical Institute, Lomonosov Moscow State University（莫斯科国立大学斯捷克列夫天文研究所）；NASA Ames Research Center（NASA艾姆斯研究中心）；Bay Area Environmental Research Institute（湾区环境研究所）
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）
We present the confirmation of a new sub-Neptune close to the transition between super-Earths and sub-Neptunes transiting the M2 dwarf TOI- 269 (TIC 220479565, V = 14.4 mag, J = 10.9 mag, Rstar = 0.40 Rsun, Mstar = 0.39 Msun, d = 57 pc). The exoplanet candidate has been identified in multiple TESS sectors, and validated with high-precision spectroscopy from HARPS and ground-based photometric follow-up from ExTrA and LCO-CTIO. We determined mass, radius, and bulk density of the exoplanet by jointly modeling both photometry and radial velocities with juliet. The transiting exoplanet has an orbit…
We report the Transiting Exoplanet Survey Satellite discovery of three small planets transiting one of the nearest and brightest M dwarf hosts to date, TOI-270 (TIC 259377017; K-mag 8.3; 22.5 parsec). The M3V-type star is transited by the super-Earth-sized TOI-270 b (1.247+0.089-0.083 R_earth) and the sub-Neptune-sized exoplanets TOI-270 c (2.42+-0.13 R_earth) and TOI-270 d (2.13+-0.12 R_earth). The planets orbit close to a mean-motion resonant chain, with periods (3.36, 5.66, and 11.38 days) near ratios of small integers (5:3 and 2:1). TOI-270 is a prime target for future studies since: 1) it…
We report the discovery of two transiting planets around the bright ($V=9.9$ mag) main sequence F7 star TOI-1670 by the Transiting Exoplanet Survey Satellite. TOI-1670 b is a sub-Neptune ($R_\mathrm{b} = 2.06_{-0.15}^{+0.19}$ $R_\oplus$) on a 10.9-day orbit and TOI-1670 c is a warm Jupiter ($R_\mathrm{c} = 0.987_{-0.025}^{+0.025}$ $R_\mathrm{Jup}$) on a 40.7-day orbit. Using radial velocity observations gathered with the Tull coudé Spectrograph on the Harlan J. Smith telescope and HARPS-N on the Telescopio Nazionale Galileo, we find a planet mass of $M_\mathrm{c} = 0.63_{-0.08}^{+0.09}$ $M_\ma…
We use Keck/NIRSPEC to survey a sample of of young ($<$1 Gyr), short period mini Neptunes orbiting nearby K dwargs to measure their mass loss via the metastable helium line. We detect helium absorption from all four of the targets in our initial sample. The first detection, around TOI 560b, was announced in a previous paper. We now announce three additional detections around TOI 1430.01, 2076b, and TOI 1683.01. All four planets show an average in-transit excess absorption of 0.7--1.0%. However, the outflows differ in their kinematic properties. TOI 1430b exhibits pre-ingress absorption, while …
TOI-1695 is a V-mag=13 M-dwarf star from the northern hemisphere at 45$\,$pc from the Sun, around which a 3.134-day periodic transit signal from a super-Earth candidate was identified in TESS photometry. With a transit depth of 1.3$\,$mmag, the radius of candidate TOI-1695.01 was estimated by the TESS pipeline to be 1.82$\,$R$_\oplus$ with an equilibrium temperature of $\sim 620\,$K. We successfully detect a reflex motion of the star and establish it is due to a planetary companion at an orbital period consistent with the photometric transit period thanks to a year-long radial-velocity monitor…
We report helium absorption from the escaping atmosphere of TOI 560.01 (HD 73583b), a $R=2.8 R_\oplus$, $P=6.4$ d mini Neptune orbiting a young ($\sim$600 Myr) K dwarf. Using Keck/NIRSPEC, we detect a signal with an average depth of $0.68 \pm 0.08$% in the line core. The absorption signal repeats during a partial transit obtained a month later, but is marginally stronger and bluer, perhaps reflecting changes in the stellar wind environment. Ingress occurs on time, and egress occurs within 12 minutes of the white light egress, although absorption rises more gradually than it declines. This sugg…
We report the discovery and validation of two TESS exoplanets orbiting faint M dwarfs: TOI-4479b and TOI-2081b. We have jointly analyzed space (TESS mission) and ground based (MuSCAT2, MuSCAT3 and SINISTRO instruments) lightcurves using our multi-color photometry transit analysis pipeline. This allowed us to compute contamination limits for both candidates and validate them as planet-sized companions. We found TOI-4479b to be a sub-Neptune-sized planet ($R_{p}=2.82^{+0.65}_{-0.63}~\rm R_{\oplus}$) and TOI-2081b to be a super-Earth-sized planet ($R_{p}=2.04^{+0.50}_{-0.54}~\rm R_{\oplus}$). Fur…
We report on the validation of two planets orbiting the nearby (36pc) M2 dwarf TOI-1266 observed by the TESS mission. The inner planet is sub-Neptune-sized ($R=2.46 \pm 0.08 R_\oplus$) with an orbital period of 10.9 days. The outer planet has a radius of $1.67_{-0.11}^{+0.09} R_\oplus$ and resides in the exoplanet Radius Valley---the transition region between rocky and gaseous planets. With an orbital period of 18.8 days, the outer planet receives an insolation flux of 2.4 times that of Earth, similar to the insolation of Venus. Using precision near-infrared radial velocities with the Habitabl…
The NASA space telescope $TESS$ is currently in the extended mission of its all-sky search for new transiting planets. Of the thousands of candidates that TESS is expected to deliver, transiting planets orbiting nearby M dwarfs are particularly interesting targets since they provide a great opportunity to characterize their atmospheres by transmission spectroscopy. We aim to validate and characterize the new sub-Neptune-sized planet candidate TOI-2136.01 orbiting a nearby M dwarf ($d = 33.36 \pm 0.02$ pc, $T_{eff} = 3373 \pm 108$ K) with an orbital period of 7.852 days. We use TESS data, groun…
[Abridged] The occurrence rate of observed sub-Neptunes has a break at 0.1 au, which is often attributed to a migration trap at the inner rim of protoplanetary disks where a positive co-rotation torque prevents inward migration. We argue that conditions in inner disk regions are such that sub-Neptunes are likely to open gaps, lose the support of the co-rotation torque as their co-rotation regions become depleted, and the trapping efficiency then becomes uncertain. We study what it takes to trap such gap-opening planets at the inner disk rim. We performed 2D locally isothermal and non-isotherma…
Magma ocean interactions can explain JWST observations of the sub-Neptune TOI-270 d
School of Earth and Space Exploration, Arizona State University（亚利桑那州立大学地球与空间探索学院）；Department of Astronomy, University of Maryland（马里兰大学天文学系）；Space Telescope Science Institute（太空望远镜科学研究所）；Department of Astronomy & Astrophysics, University of Chicago（芝加哥大学天文学与天体物理学系）；Kapteyn Astronomical Institute, University of Groningen（格罗宁根大学卡普坦天文研究所）；Earth and Planets Laboratory, Carnegie Institution for Science（卡内基科学学会地球与行星实验室）
In this paper we report the discovery of TOI-220 $b$, a new sub-Neptune detected by the Transiting Exoplanet Survey Satellite (TESS) and confirmed by radial velocity follow-up observations with the HARPS spectrograph. Based on the combined analysis of TESS transit photometry and high precision radial velocity measurements we estimate a planetary mass of 13.8 $\pm$ 1.0 M$_{Earth}$ and radius of 3.03 $\pm$ 0.15 R$_{Earth}$, implying a bulk density of 2.73 $\pm$ 0.47 $\textrm{g cm}^{-3}$. TOI-220 $b$ orbits a relative bright (V=10.4) and old (10.1$\pm$1.4 Gyr) K dwarf star with a period of $\sim$…
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）
We confirm the planetary nature of TOI-532b, using a combination of precise near-infrared radial velocities with the Habitable-zone Planet Finder, TESS light curves, ground based photometric follow-up, and high-contrast imaging. TOI-532 is a faint (J$\sim 11.5$) metal-rich M dwarf with Teff = $3957\pm69$ K and [Fe/H] = $0.38\pm0.04$; it hosts a transiting gaseous planet with a period of $\sim 2.3$ days. Joint fitting of the radial velocities with the TESS and ground-based transits reveal a planet with radius of $5.82\pm0.19$ R$_{\oplus}$, and a mass of $61.5_{-9.3}^{+9.7}$ M$_{\oplus}$. TOI-53…
As an all-sky survey, NASA's $TESS$ mission is able to detect the brightest and rarest types of transiting planetary systems, including young planets that enable study of the evolutionary processes that occur within the first billion years. Here, we report the discovery of a young, multi-planet system orbiting the bright K4.5V star, TOI-712 ($V = 10.838$, $M_\star = 0.733_{-0.025}^{+0.026} M_\odot$, $R_\star = 0.674\pm0.016 R_\odot$, $T_{\rm eff} = 4622_{-60}^{+61}$ K). From the $TESS$ light curve, we measure a rotation period of 12.48 days, and derive an age between about $500$ Myr and 1.1 Gy…
