REVEALing Signatures of Habitable Worlds Hidden by Stellar Activity

几千年来，人们一直在想，“还有其他地球存在吗？”“它们很常见吗？”“他们有生命的迹象吗？”我们现在有技术能力来回答这些问题。新的径向速度光谱仪能够探测到地球质量的行星在其可居住区域的反射运动；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，这些仪器的测量能力前所未有的精确，在实现这些目标的过程中遇到了一个基本的天体物理学障碍：恒星活动和变化对系外行星信号的污染。进一步的进展取决于解决这个“可变性问题”。REVEAL聚集了系外行星和恒星物理学领域的世界领先专家，共同解决这个问题：我们将在恒星大气磁流体动力学模拟方面取得最新进展，并通过数据驱动努力将系外行星信号与恒星变异性分开。-我们将模拟整个恒星光球湍流物理的“基本真相”，在单个对流细胞的水平上解决一个广泛的恒星类别。-我们将模拟这些“虚拟”恒星的新兴光谱，并使用与恒星径向速度和过境光谱观测相同的数据处理管道“观察”它们。我们将继续观测由TESS和PLATO发现的太阳和拥有小行星的恒星。这些恒星自身的光谱将揭示我们对恒星质量的测量以及它们大气中分子的指纹所需要的线索，从而解开恒星的变异性。我们的共同努力将使新的尖端空间观测站和地面设施充分发挥其设计的潜力，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，甚至可能在另一个星球上有生命的迹象。

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.