Mira's Wind Explored in Scattering Infrared CO Lines
Abstract
We have observed the intermediate regions of the circumstellar envelope of Mira (ο 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 β~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 3×10-7 Msolar yr-1, as derived from a simple analytic wind model. We find that the scattered intensity from the wind of Mira for 2''<~β<~7'' decreases as β-3, which suggests a time constant mass-loss rate, when averaged over 100 yr, over the past 1200 yr.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2000
- DOI:
- 10.1086/317832
- arXiv:
- arXiv:astro-ph/0008235
- Bibcode:
- 2000ApJ...545..945R
- Keywords:
-
- Stars: Circumstellar Matter;
- Infrared: Stars;
- Stars: AGB and Post-AGB;
- stars: individual (ο Ceti);
- Stars: Late-Type;
- Stars: Mass Loss;
- Astrophysics
- E-Print:
- accepted for publication in the Astrophysical Journal