REVEALing Signatures of Habitable Worlds Hidden by Stellar Activity

几千年来，人们一直想知道，“还有其他地球存在吗？”“它们很常见吗？”“它们会显示出生命迹象吗？”我们现在有技术能力回答这些问题。新的径向速度光谱仪能够探测地球质量行星在宜居带中的反射运动；詹姆斯·韦伯太空望远镜有能力探测岩石系外行星的大气层。然而，这些仪器测量能力的空前精确度面临着实现这些目标的一个根本的天体物理障碍：恒星活动和变率对系外信号的污染。进一步的进展取决于解决这个“可变性问题”。REVEAL聚集了世界领先的行星外和恒星物理专家，以协同解决这个问题：-我们将在恒星大气的磁流体动力学模拟的最新进展的基础上，和数据驱动的努力，将系外行星信号从恒星可变性中分离出来。-我们将为一大类恒星模拟在单个对流单元水平上解析的整个恒星光球的湍流物理的“地面真相”。-我们将对这些“虚拟”恒星的出射光谱进行建模，并使用与恒星径向速度和凌日光谱观测相同的数据处理管道来“观察”它们。我们将继续观察太阳和拥有泰斯和柏拉图发现的小行星的恒星。恒星自身的光谱将揭示出从我们对其行星质量和大气中分子指纹的测量中解开恒星变异性所需的线索。我们的共同努力将使新的尖端空间观测站和地面设施能够充分发挥它们的设计潜力，使我们更接近我们希望在有生之年实现的最深刻的发现--识别另一个地球，甚至另一个星球上可能存在生命的迹象。

For millennia people have wondered, "Do other Earths exist?" "Are they common?" "Would they show signs of life?". We now have the technical capability to answer these questions. New radial-velocity spectrometers are capable of detecting the reflex motions of starshosting Earth-mass planets in their habitable zones; the James Webb Space Telescope has the power to probe the atmospheres of rocky exoplanets. Yet the unprecedented precision of these instruments' measurement capabilities is up against a fundamental astrophysically-imposed barrier to achieving these goals: contamination of exoplanetary signals by stellar activity and variability. Further progress is contingent on solving this "variability problem".REVEAL gathers world-leading experts in exoplanetary and stellar physics to tackle this problem in synergy:- We will build on recent advances in magnetohydrodynamic simulations of stellar atmospheres, and data-driven efforts to separate the exoplanet signal from the stellar variability.- We will simulate the "ground truth" of the turbulent physics of entire stellar photospheres resolved at the level of individual convective cells for a broad class of stars.- We will model the emergent spectra of these "virtual" stars and "observe" them using the same data-processing pipelines as stellar radial-velocity and transit-spectroscopy observations.We will continue to observe the Sun and stars hosting small planets found with TESS and PLATO. The stars' own spectra will REVEAL the clues needed to disentangle stellar variability from our measurements of their planets' masses and the fingerprints of molecules in their atmospheres. Our unified efforts will enable the new cutting-edge space observatories and ground-based facilities to realize the full potential of their designs, bringing us closer to the most profound discoveries we could hope to achieve in our lifetimes - the identification of another Earth or even possible signs of life on another planet.