OH maser emission from young planetary nebulae.
Abstract
OH emission, primarily in the 1612 MHz satellite line and also in the main lines, is detected in a number of young planetary nebulae. These objects form a direct observational link between the evolved OH/IR stars and planetary nebulae. In this paper, the observations are presented and the implications for various aspects of Post-Asymptotic Giant Branch evolution are discussed. Lifetimes and birthrates of this evolutionary stage are calculated. A scheme for classifying preplanetary nebula objects is proposed.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 1989
- Bibcode:
- 1989A&A...217..157Z
- Keywords:
-
- Hydroxyl Emission;
- Infrared Stars;
- Interstellar Masers;
- Planetary Nebulae;
- Stellar Evolution;
- Asymptotic Giant Branch Stars;
- Color-Color Diagram;
- Very Large Array (Vla);
- Astrophysics