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arXiv · 1201.6389

The VLT-FLAMES Tarantula Survey V. The peculiar B[e]-like supergiant, VFTS698, in 30 Doradus

P. R. Dunstall·M. Fraser·J. S. Clark·P. A. Crowther·P. L. Dufton·C. J. Evans·D. J. Lennon·I. Soszyński·W. D. Taylor·J. S. Vink
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Abstract

We present an analysis of a peculiar supergiant B-type star (VFTS698/Melnick 2/Parker 1797) in the 30 Doradus region of the Large Magellanic Cloud which exhibits characteristics similar to the broad class of B[e] stars. We analyse optical spectra from the VLT-FLAMES survey, together with archival optical and infrared photometry and X-ray imaging to characterise the system. We find radial velocity variations of around 400 km/s in the high excitation Si IV, N III and He II spectra, and photometric variability of ~0.6 mag with a period of 12.7 days. In addition, we detect long-term photometric variations of ~0.25 mag, which may be due to a longer-term variability with a period of ~400 days. We conclude that VFTS698 is likely an interacting binary comprising an early B-type star secondary orbiting a veiled, more massive companion. Spectral evidence suggests a mid-to-late B-type primary, but this may originate from an optically-thick accretion disc directly surrounding the primary.

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P. R. Dunstall, M. Fraser, J. S. Clark, P. A. Crowther, P. L. Dufton, C. J. Evans, D. J. Lennon, I. Soszyński, W. D. Taylor, J. S. Vink. 2012-04-20. The VLT-FLAMES Tarantula Survey V. The peculiar B[e]-like supergiant, VFTS698, in 30 Doradus. https://doi.org/10.1051/0004-6361%2F201218872

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