Porto de Mello Gustavo, Fernandez Del Peloso Eduardo, Ghezzi Luan
Observatório do Valongo, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Astrobiology. 2006 Apr;6(2):308-31. doi: 10.1089/ast.2006.6.308.
The existence of life based on carbon chemistry and water oceans relies upon planetary properties, chiefly climate stability, and stellar properties, such as mass, age, metallicity, and galactic orbits. The latter can be well constrained with present knowledge. We present a detailed, up-to-date compilation of the atmospheric parameters, chemical composition, multiplicity, and degree of chromospheric activity for the astrobiologically interesting solar-type stars within 10 parsecs of the Sun. We determined their state of evolution, masses, ages, and space velocities, and produced an optimized list of candidates that merit serious scientific consideration by the future space-based interferometry probes aimed at directly detecting Earthsized extrasolar planets and seeking spectroscopic infrared biomarkers as evidence of photosynthetic life. The initially selected stars number 33 solar-type within the total population (excluding some incompleteness for late M-dwarfs) of 182 stars closer than 10 parsecs. A comprehensive and detailed data compilation for these objects is still lacking; a considerable amount of recent data has so far gone unexplored in this context. We present 13 objects as the nearest "biostars," after eliminating multiple stars, young, chromospherically active, hard x-ray- emitting stars, and low metallicity objects. Three of these "biostars"-- Zeta Tucanae, Beta Canum Venaticorum, and 61 Virginis -- closely reproduce most of the solar properties and are considered as premier targets. We show that approximately 7% of the nearby stars are optimally interesting targets for exobiology.
基于碳化学和水海洋的生命的存在依赖于行星特性，主要是气候稳定性，以及恒星特性，如质量、年龄、金属丰度和星系轨道。后者可以根据现有知识得到很好的限制。我们对距离太阳10秒差距内对天体生物学有意义的太阳型恒星的大气参数、化学成分、多重性和色球活动程度进行了详细、最新的汇编。我们确定了它们的演化状态、质量、年龄和空间速度，并生成了一份经过优化的候选恒星列表，这些候选恒星值得未来旨在直接探测地球大小的系外行星并寻找光谱红外生物标志物以作为光合生命证据的天基干涉测量探测器进行认真的科学考虑。最初选择的恒星在距离小于10秒差距的182颗恒星的总数（不包括一些晚期M型矮星的不完整性）中有33颗太阳型恒星。目前仍缺乏对这些天体的全面而详细的数据汇编；到目前为止，在这种情况下，大量的最新数据尚未得到探索。在排除多星、年轻、色球活动剧烈、发射硬X射线的恒星以及低金属丰度天体之后，我们提出了13个天体作为最接近的“生物恒星”。其中三颗“生物恒星”——杜鹃座ζ、猎犬座β和室女座61——与太阳的大多数特性非常相似，被视为首要目标。我们表明，大约7%的附近恒星是对外生物学最具吸引力的目标。
