Some recent results from UV observations.
Abstract
Selected IUE observations of planetary nebulae (PN) are summarized. The determination of C/O ratios and C species abundances is reviewed, taking the effects of resonance lines and dust absorption into account. In five PN with a silicate IR feature, C/O was found to be less than or equal to 0.5, while C/O was greater than about 1 for four PN with an SiC feature. Dust-opacity estimations (tauD = about 0.1) are shown to agree well with observed thermal-IR emission data. IUE and optical photometric studies of PN central stars reveal Zanstra temperatures significantly higher than those calculated by Pottasch et al. (1978). The PN K 648 in the globular cluster M15 is characterized by C/O 2.4, central-star temperature 30,000 K, and luminosity 1700 solar L (assuming the distance of M15 to be 10 kpc).
- Publication:
-
Planetary Nebulae
- Pub Date:
- 1983
- Bibcode:
- 1983IAUS..103..129S
- Keywords:
-
- Abundance;
- Carbon;
- Electron Recombination;
- Planetary Nebulae;
- Ultraviolet Astronomy;
- Dust;
- Globular Clusters;
- Iue;
- Resonance Lines;
- Stellar Spectrophotometry;
- Astronomy