2008/03/29 by M. A. Hendry, S. J. Smartt, E. D. Skillman +5 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Blue supergiant #Emission nebula #Gamma-ray bursts and supernovae #Nebula #Neon #Planetary nebula #Protoplanetary nebula #Red supergiant #Stellar evolution #Stellar, planetary, and galactic studies #Supergiant #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.13347.x
Revised after initial referee report, to appear in MNRAS. 24 pages, some figures significantly degraded, high-res copy available at http://star.pst.qub.ac.uk/~sjs/papers/sher25/
arxiv created 2008/03/29 · openalex publication_date 2008/07/14 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The blue supergiant Sher25 is surrounded by an asymmetric, hourglass-shaped circumstellar nebula. Its structure and dynamics have been studied previously through high-resolution imaging and spectroscopy, and it appears dynamically similar to the ring structure around SN1987A. Here we present long-slit spectroscopy of the circumstellar nebula around Sher25, and of the background nebula of the host cluster NGC 3603. We perform a detailed nebular abundance analysis to measure the gasphase abundances of oxygen, nitrogen, sulphur, neon and argon. The oxygen abundance in the circumstellar nebula (12 + log O/H = 8.61±0.13dex) is similar to that in the background nebula (8.56±0.07), suggesting the composition of the host cluster is around solar. However, we confirm that the circumstellar nebula is very rich in nitrogen, with an abundance of 8.91 ± 0.15, compared to the background value of 7.47 ± 0.18. A new analysis of the stellar spectrum with the fastwind model atmosphere code suggests that the photospheric nitrogen and oxygen abundances in Sher25 are consistent with the nebular results. While the nitrogen abundances are high, when