1999/10/29 by U. Oberlack, U. Wessolowski, Oberlack, U. +17
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9910555
7 pages, 4 figures, A&A in press
arxiv created 1999/10/29 · openalex publication_date 1999/10/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Wolf-Rayet binary system gamma2 Vel (WR 11 is the closest known Wolf-Rayet (WR) star. Recently, its distance has been redetermined by parallax measurements with the HIPPARCOS astrometric satellite yielding 258+41-31 pc, significantly lower than previous estimates (300 -- 450 pc). Wolf-Rayet stars have been proposed as a major source of the Galactic 26Al observed at 1.809 MeV. The gamma-ray telescope COMPTEL has previously reported 1.8 MeV emission from the Vela region, yet located closer to the Galactic plane than the position of gamma2 Vel. We derive an upper 1.8 MeV flux limit of 1.1 10-5 ph cm-2 s-1 (2 σ) for the WR star. With the new distance estimate, COMPTEL measurements place a limit of (6.3+2.1-1.4) 10-5 M_\odot the 26Al yield of gamma2 Vel, thus constrains theories of nucleosynthesis in Wolf-Rayet stars. We discuss the implications in the context of the binary nature of gamma2 Vel and present a new interpretation of the IRAS Vela shell.