Hubble Space Telescope images of the compact nebula around RY Scuti

We present HST Wide Field Planetary Camera 2 images of the very massive ecl ipsing binary RY Scuti. The HST H alpha image shows a very complex ionized nebula roughly 1 " in size. Several interesting structures are revealed, in cluding what appears to be a pair of concentric ionized rings above and bel ow the equatorial plane of the system, located at the inner edge of a more extended dust torus. We reexamine some essential physical characteristics o f the nebula, such as a possible magnetic field and the complicated mass-lo ss geometry of this near-Eddington limit contact binary. The effects of a r otating illumination source are considered to explain the brightness distri bution in the rings. We suggest a model for the origin of the mass and deta iled structure in the nebula. This model invokes a previous mass ejection t hat is shaped by nonspherical interacting winds and possibly magnetic field s.