We present high resolution J-band spectroscopy of V 393 Sco obtained with the
CRIRES at the ESO Paranal Observatory along with a discussion of archival IUE
spectra and published broad band magnitudes. The best fit to the spectral
energy distribution outside eclipse gives T1= 19000 ± 500 K for the
gainer, T2= 7250 ± 300 K for the donor, E(B−V)= 0.13 ± 0.02
mag. and a distance of d= 523 ± 60 pc, although circumstellar material
was not considered in the fit. We argue that V 393 Sco is not a member of the
open cluster M7. The shape of the He I 1083 nm line shows orbital modulations
that can be interpreted in terms of an optically thick pseudo-photosphere
mimicking a hot B-type star and relatively large equatorial mass loss through
the Lagrangian L3 point during long cycle minimum. IUE spectra show several
(usually asymmetric) absorption lines from highly ionized metals and a narrow
Lα emission core on a broad absorption profile. The overall behavior of
these lines suggests the existence of a wind at intermediate latitudes. From
the analysis of the radial velocities we find M2/M1= 0.24 ± 0.02
and a mass function of f= 4.76 ± 0.24 M⊙. Our observations favor
equatorial mass loss rather than high latitude outflows as the cause for the
long variability.Comment: 13 pages, 14 figures, 7 tables. Accepted for publication in MNRAS,
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