Abstract
The planetary nebulae He 2-436 and Wray 16-423 in the Sagittarius dwarf galaxy appear to result from nearly twin stars, except that third-dredge-up carbon is more abundant in He 2-436. A thorough photoionization-model analysis implies that ratios Ne/O, S/O and Ar/O are significantly smaller in He 2-436, indicative of third-dredge-up oxygen enrichment. The enrichment of oxygen with respect to carbon is (7±4)%. Excess nitrogen inWray 16-423 suggests third dredge-up of late-CN-cycle products even in these low-mass, intermediate-metallicity stars.
| Original language | English |
|---|---|
| Pages (from-to) | L1-L4 |
| Number of pages | 4 |
| Journal | Astronomy and Astrophysics |
| Volume | 361 |
| Issue number | 1 |
| Publication status | Published - Sept 2000 |
Keywords
- nuclear reactions
- nucleosynthesis
- planetary nebulae
- galaxies
- Sagittarius
- stars