| Elem. | Present | Exter(1) | Aller(2) | Solar(3) |
| He | 0.123 | 0.141 | 0.145 | 0.085 |
| N(-4) | 8.4 | 12.3 | 11.5 | 0.60 |
| O(-4) | 5.0 | 3.9 | 6.6 | 4.6 |
| Ne(-4) | 2.2 | 4.1 | 1.2 | 1.2 |
| S(-6) | 11.0 | 6.7 | 8.9 | 14. |
| Ar(-6) | 6.0 | 5.6 | 10.0 | 4.2 |
| Mg(-5) | 1.7 | 3.4 | ||
| Na(-6) | 3.2 | 1.5 | ||
| Fe(-6) | 4.0 | 28. | ||
| Cl(-7) | 2.8 | 4.0 | 3.2 |
(1) Exter et al. (2004); (2) Aller & Keyes (1987); (3) Solar: Asplund et al. (2005).