Program: GS-2009A-C-9
Title: | Fast Winds from Stars in M4 |
PI: | Andrea Dupree |
Co-I(s): | Graeme Smith, Jay Strader |
Abstract
Direct detection of winds from giant stars in globular clusters
remains elusive although stellar evolution of low mass stars
requires mass loss on the red giant branch in order to reproduce
the horizontal branch morphology. The \ion{He}{1} 1.0830\micron\ line
observed in field metal-poor stars shows that fast ($\sim$100 km/s)
winds occur in warm giants and also red horizontal branch stars
in amounts with evolutionary significance. We propose to use
PHOENIX to measure the \ion{He}{1} 1.0830\micron\ line in
giants and horizontal branch stars of the globular cluster M4 to detect fast
mass outflows. Wind speeds may allow material to escape the
cluster and solve the mystery of the missing interstellar medium
in globular clusters.
Non-LTE semi-empirical modeling of the winds based on these
profiles combined with existing high resolution optical
spectra, will establish stellar mass loss rates for metal-poor stars.
Publications using this program's data
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[data]
[ADS] Structure and Dynamics of the Accretion Process and Wind in TW Hya
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[data]
[ADS] The 10830 Å Helium Line Among Evolved Stars in the Globular Cluster M4