Discovery and Characterization of Transiting Super Earths Using an All-Sky Transit Survey and Follow-up by the James Webb Space Telescope
Discovery and Characterization of Transiting Super Earths Using an All-Sky Transit Survey and Follow-up by the James Webb Space Telescope
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DOI：
10.1086/605913
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发表时间：
2009-09-01
影响因子：
3.5
通讯作者：
Ennico, K.
中科院分区：
文献类型：
--
作者：
Deming, D.;Seager, S.;Ennico, K.
多普勒和凌日巡天正在寻找质量和半径越来越小的太阳系外行星，并且现在正在对超级地球（1-3R（圆加））范围进行采样。多普勒巡天的最新结果表明，在较低主序星的宜居带中发现凌日超级地球是可能的。我们评估了针对最亮恒星的全天空凌日调查的前景，这将找到使用詹姆斯·韦伯太空望远镜（JWST）进行光度和光谱表征的最有利的情况。我们使用拟议的凌日系外行星勘测卫星（TESS）作为全天勘测的代表。我们将模拟的 TESS 产量与 JWST 上 MIRI 和 NIRSpec 仪器的灵敏度模型相结合。我们的灵敏度模型包括这些仪器的所有当前已知和预期的随机和系统误差来源。我们关注半径介于地球和海王星之间的 TESS 行星。我们的模拟考虑使用 JWST/MIRI 进行二次食过滤光度测量，比较 11 和 15 μm 波段以测量超级地球中的 CO2 吸收，以及 JWST/NIRSpec 光谱的 1.7-3.0 μm 水吸收和 4.3 μm 处 CO2 吸收。我们发现 JWST 将能够使用 MIRI 和 NIRspec 来表征数十个温度高于宜居范围的 TESS 超级地球。我们预计 TESS 将发现附近大约八颗可居住的凌日超级地球，它们都围绕较低主序恒星运行。预期的 JWST 对可居住超级地球进行表征的不确定性的主要来源是超级地球频率和超级地球大气层的性质。根据我们对这些不确定性的估计，我们预计 JWST 将能够测量温度并识别附近一到四个绕低主序恒星运行的可居住 TESS 超级地球的分子吸收（水、二氧化碳）。
Doppler and transit surveys are finding extrasolar planets of ever smaller mass and radius, and are now sampling the domain of super Earths (1-3R(circle plus)). Recent results from the Doppler surveys suggest that discovery of a transiting super Earth in the habitable zone of a lower main sequence star may be possible. We evaluate the prospects for an all-sky transit survey targeted to the brightest stars, that would find the most favorable cases for photometric and spectroscopic characterization using the James Webb Space Telescope (JWST). We use the proposed Transiting Exoplanet Survey Satellite (TESS) as representative of an all-sky survey. We couple the simulated TESS yield to a sensitivity model for the MIRI and NIRSpec instruments on JWST. Our sensitivity model includes all currently known and anticipated sources of random and systematic error for these instruments. We focus on the TESS planets with radii between those of Earth and Neptune. Our simulations consider secondary eclipse filter photometry using JWST/MIRI, comparing the 11 and 15 mu m bands to measure CO2 absorption in super Earths, as well as JWST/NIRSpec spectroscopy of water absorption from 1.7-3.0 mu m, and CO2 absorption at 4.3 mu m. We find that JWST will be capable of characterizing dozens of TESS super Earths with temperatures above the habitable range, using both MIRI and NIRspec. We project that TESS will discover about eight nearby habitable transiting super Earths, all orbiting lower-main-sequence stars. The principal sources of uncertainty in the prospective JWST characterization of habitable super Earths are super-Earth frequency and the nature of super-Earth atmospheres. Based on our estimates of these uncertainties, we project that JWST will be able to measure the temperature and identify molecular absorptions (water, CO2) in one to four nearby habitable TESS super Earths orbiting lower-main-sequence stars.