Cool Stars 14 - Submitted Abstract # 47
This version created on 05 October 2006

Interferometric angular diameters, linear radii and stellar modeling


Pierre Kervella, Observatoire de Paris

Long baseline interferometry can now provide stellar angular
diameterswith sub-percent accuracy.  Using the VLTI and the VINCI
instrument, we have observed a number of dwarf stars and subgiants in
the solar neighborhood.  This allowed us to calibrate surface
brightness-color relations based on interferometric angular diameters
and broadband photometry.  These relations are useful to predict the
angular size of distant stars currently unresolved by interferometers.
Through a combination of angular sizes and existing Hipparcos
parallaxes, we also obtained accurate estimates of the linear radius
of several nearby stars:  Procyon, Alpha Cen A & B,...  The radius is
a strong constraint for evolutionary stellar models, especially when
combined with asteroseismic data.  I will present our modeling of
these stars with the CESAM code, constrained using spectrophotometry,
linear radius, and asteroseismic frequencies.  Beyond the angular
diameter, long-baseline interferometry can also provide limb darkening
measurements.  I will present examples of how this can be used as a
constraint for stellar atmosphere models.

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