Extended 60 micron Emission From Nearby Mira Variables
Abstract
The Infrared Astronomy Satellite (IRAS) has detected extended emission around a number of evolved stars. Individual IRAS scans of nearby Mira variables which showed emission from circumstellar dust and for which distance estimates were available were examined. Extended emission at 60 micrometers was detected for R Cas, o Cet, R Leo, U Ori, and possibly for R Hor. The Leung code for the calculation of radiative transfer in a circumstellar dust shell was used to calculate the emission from model dust shells composed of silicate grains. The output was convolved with the IRAS beam profile to determine whether steady mass loss could explain the observed extension. The observed extensions for o Cet, R Hor and U Ori could be due to steady mass loss, while the model calculations do not produce enough extension to explain the observations of R Cas and R Leo.
- Publication:
-
The Astronomical Journal
- Pub Date:
- June 1994
- DOI:
- 10.1086/117034
- Bibcode:
- 1994AJ....107.2233H
- Keywords:
-
- Infrared Astronomy;
- Infrared Astronomy Satellite;
- Near Infrared Radiation;
- Radiative Transfer;
- Stellar Evolution;
- Stellar Radiation;
- Variable Stars;
- Emission Spectra;
- Optical Thickness;
- Stellar Temperature;
- Astronomy;
- INFRARED: STARS;
- ACCRETION DISKS