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

Aims: 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.
Methods: We analyse optical spectra from the VLT-FLAMES survey, together with archival optical and infrared photometry and X-ray imaging to characterise the system.
Results: We find radial velocity variations of around 400 km s^-1 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 d. 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 d.
Conclusions: 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.

Based on observations at the European Southern Observatory Very Large Telescope in programme 182.D-0222.Table 8 is available in electronic form at http://www.aanda.org