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Paper: |
Long-term Spectroscopic Monitoring of Cool Hypergiants HR 8752, IRC+10420, and 6 Cas near the Yellow Evolutionary Void |
Volume: |
470, 370 Years of Astronomy in Utrecht |
Page: |
167 |
Authors: |
Lobel, A.; de Jager, K.; Nieuwenhuijzen, H. |
Abstract: |
We discuss the spectral variability of three white (A-type) hypergiants (Ia+) near the region of atmospheric dynamical instability in the upper H-R diagram, called the Yellow Evolutionary Void. The Void represents an obstacle for the fast blueward evolution of the most massive cool hypergiant stars. Optical and near-IR spectra observed between 1993 and 2011 with several high-resolution spectrographs, including the WHT-Utrecht Echelle Spectrograph, Mercator-HERMES, NOT-Sofin, and Keck-HIRES, are compared to investigate the wind-physics and -dynamics of the hypergiants. |
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