We present VLT/UVES spectroscopic and VLTI/VINCI interferometric observations of the cool giant α Cet (M2 III). Spherically symmetric PHOENIXstellar atmosphere models are tested by comparison with our spectroscopic and interferometric observations. The high spectral resolution of UVES allows us to constrain the effective temperature and the surface gravity of the star by comparing observed and model predicted bands that are temperature and gravity indicators. High angular resolution and high precision VLTI/VINCI observations directly measure the strength of the limb darkening effect of α Cet in the K-band. We derive fundamental stellar parameters, namely a Rosseland diameter of 12.08±0.18 mas corresponding to a Rosseland linear radius of 88±6 R☉, and an effective temperature of 3805<sup>+95</sup> <sub>-109</sub> K, using the Hipparcos parallax and the bolometric flux.
Spectroscopic and Interferometric Tests of Stellar Atmosphere Models: UVES and VINCI Measurements of the M-giant α Cet
Roccatagliata, V.;
2008-01-01
Abstract
We present VLT/UVES spectroscopic and VLTI/VINCI interferometric observations of the cool giant α Cet (M2 III). Spherically symmetric PHOENIXstellar atmosphere models are tested by comparison with our spectroscopic and interferometric observations. The high spectral resolution of UVES allows us to constrain the effective temperature and the surface gravity of the star by comparing observed and model predicted bands that are temperature and gravity indicators. High angular resolution and high precision VLTI/VINCI observations directly measure the strength of the limb darkening effect of α Cet in the K-band. We derive fundamental stellar parameters, namely a Rosseland diameter of 12.08±0.18 mas corresponding to a Rosseland linear radius of 88±6 R☉, and an effective temperature of 3805+95 -109 K, using the Hipparcos parallax and the bolometric flux.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
