2009/09/30 by V. V. Gvaramadze, A. Y. Kniazev, S. Fabrika · 47 citations
Physics and Astronomy · Social Sciences · #Astronomy and Astrophysical Research #Educational Leadership and Practices #Large Magellanic Cloud #Milky Way #O-type star #Photometer #Population #Spectroscopy #Stars #Stellar, planetary, and galactic studies #Supergiant #astro-ph.SR
paper · pdf · doi:10.1111/j.1365-2966.2010.16496.x
published in Monthly Notices of the Royal Astronomical Society (Oxford University Press) · 9 pages, 10 figures, accepted to MNRAS
arxiv created 2010/02/08 · openalex publication_date 2010/03/01 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Massive evolved stars lose a large fraction of their mass via copious stellar wind or instant outbursts. During certain evolutionary phases, they can be identified by the presence of their circumstellar nebulae. In this paper, we present the results of a search for compact nebulae (reminiscent of circumstellar nebulae around evolved massive stars) using archival 24-μm data obtained with the Multiband Imaging Photometer for <it>Spitzer</it>. We have discovered 115 nebulae, most of which bear a striking resemblance to the circumstellar nebulae associated with luminous blue variables (LBVs) and late WN-type (WNL) Wolf–Rayet (WR) stars in the Milky Way and the Large Magellanic Cloud (LMC). We interpret this similarity as an indication that the central stars of detected nebulae are either LBVs or related evolved massive stars. Our interpretation is supported by follow-up spectroscopy of two dozen of these central stars, most of which turn out to be either candidate LBVs (cLBVs), blue supergiants or WNL stars. We expect that the forthcoming spectroscopy of the remaining objects from our list, accompanied by the spectrophotometric monitoring of the already discovered cLBVs, will further increase the known population of Galactic LBVs. This, in turn, will have profound consequences for better understanding the LBV phenomenon and its role in the transition between hydrogen-burning O stars and helium-burning WR stars. We also report on the detection of an arc-like structure attached to the cLBV HD 326823 and an arc associated with the LBV R99 (HD 269445) in the LMC.