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Paper: Astrobiologically Interesting Stars Near the Sun: Galactic Orbits and Mass Extinctions
Volume: 420, Bioastronomy 2007: Molecules, Microbes and Extraterrestrial Life
Page: 349
Authors: Porto de Mello, G. F.; Lépine, J. R.; da Silva Dias, W.
Abstract: Life based on carbon chemistry, water oceans and planetary surfaces relies upon stellar properties, such as mass, age and chemical composition, which can be well constrained for nearby stars. Our goal is to produce a catalogue of Sun-like stars, nearer than 15 parsecs, which may have harbored Earth-like planets within their continuously habitable zone (CHZ) for the last ∼3 Gyr (giga-years). We determined their masses, ages and galactic orbits. These objects should be prime targets for future space-based missions aimed at detecting, interferometrically, spectral infrared biomarkers and thereby deducing the presence of oxygenated atmospheres and photosynthesizing life in extra-solar Earth-like planets. We show that ∼7% of the nearby stars have optimum astrobiological interest, and that only ∼2% have characteristics truly approaching the Sun’s. The solar galactic orbit is shown to submit Earth’s biosphere to long passages through the galactic spiral arms. If these passages offer a biological hazard, most stars of the neighborhood offer more benign environments than the Sun.
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