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Projeto Observacional para 2009A - OP2009A-003
Autor: Roberto D.Dias da Costa
Título: The Power at the Heart of Symbiotic Systems
Resumo: Symbiotic stars are wide interacting binaries in which a hot compact star that is usually a white dwarf (WD) accretes hydrogen-rich material from a red-giant companion. The hot WD ionizes the surrounding wind nebula, which then produces high excitation emission lines. For many symbiotic stars, the most basic question remains unanswered: what is the dominant source of energy powering the symbiotic behavior? This question is fundamental to our understanding of the symbiotic phenomenon. To tackle this problem we will use the GALEX satellite to carry out a Snap survey of high Galactic-latitude (i.e., relatively nearby, low extinction) symbiotics to determine whether these systems are predominantly powered by accretion or nuclear shell burning. These observations will be combined to optical spectroscopy at OPD to determine the extinction and distance for each object, which are essential parameters to our analysis.