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| Paper: |
PIONIERing Diameter Measurements of Globular Cluster Giants |
| Volume: |
497, Why Galaxies Care about AGB Stars III: A Closer Look in Space and Time |
| Page: |
485 |
| Authors: |
Hron, J.; Bouquin, J. L.; Lebzelter, T.; Paladini, C.; Soszynski, I.; Berger, J.-P.; Boffin, H. M. J.; Wittkowski, M. |
| Abstract: |
We present an attempt to resolve for the first time one of the brightest
long period variables in the globular cluster 47 Tuc with PIONIER in the
H band. Based on model atmospheres and observations of local LPVs, the
predicted visibilities were
about 0.9, i.e. they are at the limit of feasibility with PIONIER.
The observations show that the star is unresolved with an upper limit
of 0.44 mas for the uniform disk (UD) diameter in the H band. This is
in agreement with the predictions from
stellar evolution models and from a dynamic model with similar stellar
parameters. Spatial frequencies of B[m] / λ[μm]> 150
are necessary to resolve this star and to distinguish between different
models, but these are beyond those currently accessible with VLTI. |
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