Arbitrary-width confined states of traveling-wave convection: Pinning, locking, drift, and stability

I describe observations of ``arbitrary-width'' confined states of traveling-wave convection in an ethanol-water mixture with separation ratio {ψ}=-0.253, made in an extremely uniform annular cell. The time derivative of the spatial width of these confined states vanishes at a unique, width-dependent Rayleigh number, not over a finite band of Rayleigh numbers as previously reported. Also, the confined states drift slowly around the cell, backwards.