On the nature of the galactic early-B hypergiants

Abstract

Despite their importance to a number of astrophysical fields, the lifecycles of very massive stars are still poorly defined. In order to address this shortcoming, we present a detailed quantitative study of the physical properties of four early-B hypergiants (BHGs); Cyg OB2 #12, zeta Sco, HD190603 and BP Cru. These are combined with an analysis of their long-term spectroscopic and photometric behaviour in order to determine their evolutionary status. The long-term datasets revealed that they are remarkably stable over long periods (>40yr), with the possible exception of zeta Sco prior to the 20th century, in contrast to the typical excursions that characterise luminous blue variables (LBVs). Zeta Sco, HD190603 and BP Cru possess physical properties intermediate between B supergiants and LBVs; we therefore suggest that BHGs are the immediate descendants and progenitors (respectively) of such stars (for initial masses in the range ~30-60Msun). In contrast, while the wind properties of Cyg OB2 #12 are consistent with this hypothesis, the combination of extreme luminosity and spectroscopic mass (~110Msun) and comparatively low temperature means it cannot be accommodated in such a scheme. Likewise, despite its co-location with several LBVs above the Humphreys-Davidson (HD) limit, the lack of long term variability and its unevolved chemistry apparently excludes such an identification. Since such massive stars are not expected to evolve to such cool temperatures, the properties of Cyg OB2 #12 are difficult to understand under current evolutionary paradigms. [ABRIDGED]

36 pages, 19 figures (of which 17 pages are online supplemental material). Accepted for publication in Astronomy and Astrophysics

References in corpus (20)

• UBVJHK synthetic photometry of Galactic O stars
• The most massive stars in the Arches cluster
• Stellar and wind properties of massive stars in the central parsec of the Galaxy
• Bright OB stars in the Galaxy IV. Stellar and wind parameters of early to late B supergiants
• An XMM-Newton view of the young open cluster NGC 6231 -- II. The OB star population
• Quantitative studies of the optical and UV spectra of Galactic early B supergiants I. Fundamental parameters
• On the role of the WNH phase in the evolution of very massive stars: Enabling the LBV instability with feedback
• VLT/UVES spectroscopy of Wray 977, the hypergiant companion to the X-ray pulsar GX301-2
• On the nature of the galactic early-B hypergiants
• Unveiling the Cygnus OB2 stellar population with Chandra
• The Quintuplet Cluster I. A K-band spectral catalog of stellar sources
• Spectral atlas of massive stars around He I 10830 A
• A Three-Decade Outburst of the LMC Luminous Blue Variable R127 Draws to a Close
• An XMM-Newton view of the young open cluster NGC 6231 III. Optically faint X-ray sources
• On the nature of the prototype LBV AG Carinae II. Witnessing a massive star evolving close to the Eddington and bistability limits
• Testing the predicted mass-loss bi-stability jump at radio wavelengths
• An XMM-Newton view of the young open cluster NGC 6231 -- I. The catalogue
• The blue supergiant Sher 25 and its intriguing hourglass nebula
• High resolution optical spectroscopy of an LBV-candidate inside the CygOB2 association
• The Rich Mid-Infrared Environments of Two Highly-Obscured X-ray Binaries: Spitzer Observations of IGR J16318-4848 and GX 301-2

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