2007/03/27 by Cristina M. Oliveira, Cristina M Oliveira, Pierre Chayer +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Emission nebula #Interstellar medium #Ionization #Line (geometry) #Line-of-sight #Nebula #Planetary nebula #Spectral line #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/518435
Accepted for publication is ApJL
arxiv created 2007/03/27 · openalex publication_date 2007/04/24 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present FUSE observations of the line of sight to WD 0439+466 (LS V +46 21), the central star of the old planetary nebula Sh 2-216. The FUSE data show absorption by many interstellar and stellar lines, in particular D I, H 2 ( J = 0-9), HD J = 0-1, and CO. Many other stellar and ISM lines are detected in the STIS E140M HST spectra of this sight line, which we use to determine N (H I). We derive, for the neutral gas, D/H = 0.76 × 10 -5 , O/H = 0.89 × 10 -4 , and N/H = 3.24 × 10 -5 . We argue that most of the gas along this sight line is associated with the planetary nebula. The low D/H ratio is likely the result of this gas being processed through the star (astrated) but not mixed with the ISM. This would be the first time that the D/H ratio has been measured in predominantly astrated gas. The O/H and N/H ratios derived here are lower than typical values measured in other planetary nebulae likely due to unaccounted for ionization corrections.