From: LARRY KLAES (ljk4_at_msn.com)
Date: Tue Nov 08 2005 - 08:30:37 PST
Astrophysics, abstract
astro-ph/0511180
From: Eduardo Fernandez del Peloso [view email]
Date: Mon, 7 Nov 2005 14:49:49 GMT (264kb)
Astrobiologically Interesting Stars within 10 parsecs of the Sun
Authors: G.F. Porto de Mello (1), E.F. del Peloso (1 and 2), L. Ghezzi (2)
((1) Observatorio do Valongo/UFRJ, Rio de Janeiro, Brazil, (2) Observatorio
Nacional/MCT, Rio de Janeiro, Brazil)
Comments: 36 pages, recommended for publication in Astrobiology
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 determine
their state of evolution, masses, ages and space velocities, and produce an
optimized list of candidates that merit serious scientific consideration by
the future space-based interferometry probes aimed at directly detecting
Earth-sized extrasolar planets and seeking spectroscopic infrared biomarkers
as evidence of photosynthetic life. The initially selected stars number 33
solar-type within the population of 182 stars (excluding late M-dwarfs)
closer than 10 pc. A comprehensive and detailed data compilation for these
objects is still essentially 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", HD 1581, 109358 and 115617, 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.
http://arxiv.org/abs/astro-ph/0511180
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