Have superhumps been seen in black hole soft X-ray transients?

Abstract

Superhumps are always seen in the superoutbursts of the SU UMa subclass of dwarf novae. Current understanding of the phenomenon as arising from tidal stressing of accretion discs in high-mass-ratio (q > 3) interacting binaries suggests that they should be detectable in other kinds of semidetached binaries with extreme mass ratios, including the black hole soft X-ray transients (SXTs).