Chemical composition and origin of the Wolf-Rayet ring Nebula NGC 6888

Journal Article · Wed Apr 01 04:00:00 EST 1981 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/158796· OSTI ID:6452282

Kwitter, K B

We have obtained spectrophotometric observations of NGC 6888, a ring nebula surrounding the Population I Wolf-Rayet star HD 192163, in order to determine the physical conditions and chemical abundances in this object. We conclude that NGC 6888 is enriched in nitrogen and helium by factors of about 9 and 2, respectively, compared with the Orion Nebula. This enrichment is a result of contamination of the ambient abundances by the nigrogen-rich and helium-rich wind from the central Wolf-rayet star. We have interpreted NGC 6888 as an interstellar bubble, according to recent theory, and calculate an approximate age for the nebula of 18,000 years. The fraction of nebular mass contributed by the central star can be estimated from published stellar abundances; we calculate that the stellar wind has provided approx.10% of the observed nebular mass. If this nebula is representative, then the total mass contributed to a ring nebula by stellar wind is small (< or approx. =1M/sub sun/). This suggests that mass loss from stars in the Wolf-Rayet phase does not play a significant role in the nitrogen and helium enrichment of the interstellar medium.

• Research Organization: Astronomy Department, University of California, Los Angeles
• OSTI ID: 6452282
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 245:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics &amp; Cosmology-- Stars &amp; Quasi-Stellar
Radio &amp; X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CHEMICAL COMPOSITION
ELEMENTS
FLUIDS
GASES
HELIUM
INTERSTELLAR SPACE
MAIN SEQUENCE STARS
NEBULAE
NITROGEN
NONMETALS
RARE GASES
SPACE
SPECTROPHOTOMETRY
STAR EVOLUTION
STARS
STELLAR WINDS
WOLF-RAYET STARS