Mira's wind explored in scattering infrared CO lines
Abstract
We have observed the intermediate regions of the circumstellar envelope of Mira (o Ceti) in photospheric light scattered by three vibration-rotation transitions of the fundamental band of CO, from low-excited rotational levels of the ground vibrational state, at an angular distance of beta = 2"-7" away from the star. The data were obtained with the Phoenix spectrometer mounted on the 4 m Mayall telescope at Kitt Peak. The spatial resolution is approximately 0.5" and seeing limited. Our observations provide absolute fluxes, leading to an independent new estimate of the mass-loss rate of approximately 3e-7 Msun/yr, as derived from a simple analytic wind model. We find that the scattered intensity from the wind of Mira for 2" < beta < 7" decreases as beta^-3, which suggests a time constant mass-loss rate, when averaged over 100 years, over the past 1200 years.
Keywords
Cite
@article{arxiv.astro-ph/0008235,
title = {Mira's wind explored in scattering infrared CO lines},
author = {N. Ryde and B. Gustafsson and K. Eriksson and K. H. Hinkle},
journal= {arXiv preprint arXiv:astro-ph/0008235},
year = {2009}
}
Comments
accepted for publication in the Astrophysical Journal