Nine transiting Earth-sized planets have recently been discovered around nearby late M dwarfs, including the TRAPPIST-1 planets and two planets discovered by the MEarth survey, GJ 1132b and LHS 1140b. These planets are the smallest known planets that may have atmospheres amenable to detection with JWST. We present model thermal emission and transmission spectra for each planet, varying composition and surface pressure of the atmosphere. We base elemental compositions on those of Earth, Titan, and Venus and calculate the molecular compositions assuming chemical equilibrium, which can strongly depend on temperature. Both thermal emission and transmission spectra are sensitive to the atmospheric composition; thermal emission spectra are sensitive to surface pressure and temperature. We predict the observability of each planet's atmosphere with JWST. GJ 1132b and TRAPPIST-1b are excellent targets for emission spectroscopy with JWST/MIRI, requiring fewer than 10 eclipse observations. Emission photometry for TRAPPIST-1c requires 5-15 eclipses; LHS 1140b and TRAPPIST-1d, TRAPPIST-1e, and TRAPPIST-1f, which could possibly have surface liquid water, may be accessible with photometry. Seven of the nine planets are strong candidates for transmission spectroscopy measurements with JWST, though the number of transits required depends strongly on the planets' actual masses. Using the measured masses, fewer than 20 transits are required for a 5 sigma detection of spectral features for GJ 1132b and six of the TRAPPIST-1 planets. Dedicated campaigns to measure the atmospheres of these nine planets will allow us, for the first time, to probe formation and evolution processes of terrestrial planetary atmospheres beyond our solar system.
Can Carbon Fractionation Provide Evidence for Aerial Biospheres in the Atmospheres of Temperate Sub-Neptunes?
对其他星球生命迹象的搜寻主要集中在类地行星上。然而,最近的研究认为,生命可能存在于温带亚海王星的大气中。在这里,我们评估二氧化碳同位素作为空中生命证据的有用性。碳同位素特别重要,因为代谢过程优先使用较轻的$^{12}$ C而不是$^{13}$ C。原则上,即将到来的詹姆斯韦伯太空望远镜(JWST)将能够光谱解析CO $_{2}$的$^{12}$ C和$^{13}$ C同位素,但不能解析CO和CH $_{4}$。我们模拟了观测CO $_{2}$同位素在H $_{2}$为主的大气中我们最近的($< 40$ pc),温带(平衡温度为250-350 K)次海王星与M矮宿主星。我们发现$^{13}$ CO $_{2}$和$^{12}$ CO $_{2}$是可区分的,如果大气层是H $_{2}$为主的几个百分点的CO $_{2}$的最理想的目标与地球一样的组成的两个最丰富的同位素,$^{12}$ CO $_{2}$和$^{13}$ CO $_{2}$。由于类海王星的金属丰度为100 $\times$太阳能,C/O为0.55,我们无法在温带次海王星的大气中区分$^{13}$ CO $_{2}$和$^{12}$ CO $_{2}$。如果大气成分基本上遵循金属丰度标度,则在H $_{2}$占主导地位的大气中,CO $_{2}$的浓度将过低,无法区分CO $_{2}$同位素与JWST。相比之下,在较高…
Molecular mapping of an exoplanet with JWST: NH3 detection in the temperate super-Jupiter Epsilon Indi Ab
Institut de Recherche en Astrophysique et Planétologie(天体物理学与行星学研究所在);École polytechnique, Institut Polytechnique de Paris(巴黎综合理工学院,巴黎理工学院);Observatoire de Paris(巴黎天文台)
利用JWST红外光谱和交叉相关技术,对直接成像的温带超级木星Epsilon Indi Ab进行分子测绘,可靠探测到NH3、H2O、CH4,并边缘性探测到CO2,验证了该方法在强恒星污染下的有效性。
Hydrocarbon Hazes on Temperate sub-Neptune K2-18b supported by data from the James Webb Space Telescope
University College London(伦敦大学学院);Universite de Reims Champagne Ardenne(兰斯香槟阿登大学);King’s College London(伦敦国王学院);Osservatorio Astronomico di Palermo(巴勒莫天文台)
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)
The Mid-Infrared Transmission Spectrum of the Temperate Sub-Neptune TOI-270 d
Space Telescope Science Institute(太空望远镜科学研究所);Institute of Astronomy, University of Cambridge(剑桥大学天文研究所);School of Physics and Astronomy, Cardiff University(卡迪夫大学物理与天文学学院);Space Science Institute(太空科学研究所)
A Homogeneous Survey of JWST MIRI Transmission Spectra of 10 Exoplanets
Institute of Astronomy, University of Cambridge(剑桥大学天文学研究所);Space Telescope Science Institute(太空望远镜科学研究所);School of Physics and Astronomy, Cardiff University(卡迪夫大学物理与天文学院)
Photochemical Production of CS2 in Temperate-to-Warm Gas Giant Exoplanet Atmospheres
University of Chicago(芝加哥大学);Arizona State University(亚利桑那州立大学);University of California, Santa Cruz(加州大学圣克鲁兹分校);Carnegie Institution for Science(卡内基科学机构)
Three outstanding physical questions for K2-18 b and other temperate sub-Neptunes
Institute of Astronomy & Astrophysics, Academia Sinica(中央研究院天文及天文物理研究所);HFML-FELIX(高频磁场设施-费利克斯实验室);JHU Applied Physics Laboratory(约翰斯·霍普金斯大学应用物理实验室);ETH Zurich, Institute for Particle Physics & Astrophysics(苏黎世联邦理工学院粒子物理与天体物理研究所);Deutsches Elektronen-Synchrotron DESY(德国电子同步加速器中心);Department of Earth and Planetary Sciences, University of California, Riverside(加州大学河滨分校地球与行星科学系);Virtual Planetary Laboratory, University of Washington(华盛顿大学虚拟行星实验室);Blue Marble Space Institute of Science(蓝大理石空间科学研究所);Department of Astrophysics, IMAPP, Radboud University(拉德堡德大学IMAPP天体物理学系);SRON Leiden(莱顿荷兰太空研究所)
Not Earth-like Yet Temperate? More Generic Climate Feedback Configurations Still Allow Temperate Climates in Habitable Zone Exo-Earth Candidates
Lunar and Planetary Laboratory, The University of Arizona(月球与行星实验室,亚利桑那大学);Steward Observatory, The University of Arizona(斯图尔德天文台,亚利桑那大学);James C. Wyant College of Optical Sciences, The University of Arizona(詹姆斯·C·怀扬特光学科学学院,亚利桑那大学)
Understanding the chemistry of temperate exoplanets atmospheres through experimental and numerical simulations
UVSQ Université Paris-Saclay, Sorbonne Université, CNRS(凡尔赛大学巴黎萨克雷大学、索邦大学、法国国家科学研究中心);ETH University, Center for Origin and Prevalence of Life, Department of Earth and Planetary Sciences(苏黎世联邦理工学院,生命起源与普遍性中心,地球与行星科学系);ENS-Paris-Saclay(巴黎萨克雷高等师范学校)
Three-dimensional transport-induced chemistry on temperate sub-Neptune K2-18b, Part II: the combined effects of atmospheric dynamics and chemical reactions
Max Planck Institute for Astronomy(马克斯·普朗克天文学研究所);Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University(北京大学物理学院大气与海洋科学系);Department of Physics and Astronomy, Faculty of Environment, Science and Economy, University of Exeter(埃克塞特大学环境、科学与经济学院物理与天文系)
Jet Propulsion Laboratory, California Institute of Technology(加州理工学院喷气推进实验室);The Pennsylvania State University(宾夕法尼亚州立大学);The University of Chicago(芝加哥大学);Arizona State University(亚利桑那州立大学);Johns Hopkins University(约翰斯·霍普金斯大学);Carnegie Institution for Science(卡内基科学机构)