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The Castor Moving Group: The age of Fomalhaut and Vega

D. Barrado y Navascues
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Abstract

We have recomputed the kinematic properties of several of dozens nearby stars, to try to verify if Castor has a cohort of stars sharing the same space motion and age. We used kinematics, the location of the stars in CM diagrams, their lithium abundances, and their activity, to establish that the moving group seems to be real and to reject several stars which were believed to be part of this group. Of the initial 26 stars, we show that probably only 16 stars are physically associated. The moving group contains several A spectral type stars. Among them, Vega and Fomalhaut, two of the prototypes of the beta Pic type stars. Since this association includes several late spectral type stars, we used their properties to estimate their age and, therefore, the age of the group and that of Vega and Fomalhaut. Our estimate for that age is 200$\pm$100 Myr.

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D. Barrado y Navascues. 1999-05-19. The Castor Moving Group: The age of Fomalhaut and Vega. https://arxiv.org/abs/astro-ph/9905243

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