Overloaded and fractured stellar winds

Stellar Winds in Interaction

WR140 (WC7pd + O5) is often considered to be the archetype of hot, luminous colliding-wind binaries, with strong cyclic high-energy and dust-formation events. The challenge is that this system is quite extreme, with a long period (nearly an integral 7.94 years) and high eccentricity (e = 0.88). Most of the action thus occurs during the relatively short several-month interval of close periastron...

Stellar Winds from Massive Stars

We review the various techniques through which wind properties of massive stars – O stars, AB supergiants, Luminous Blue Variables (LBVs), Wolf-Rayet (WR) stars and cool supergiants – are derived. The wind momentum-luminosity relation (e.g. Kudritzki et al. 1999) provides a method of predicting mass-loss rates of O stars and blue supergiants which is superior to previous parameterizations. Assu...

Runaway of Line-driven Winds toward Critical and Overloaded Solutions.

Line-driven winds from hot stars and accretion disks are thought to follow a unique, critical solution that corresponds to a maximum mass-loss rate and a particular velocity law. We show that in the presence of negative velocity gradients, radiative-acoustic (Abbott) waves can drive shallow wind solutions toward larger velocities and mass-loss rates. Perturbations that are introduced downstream...

Astrospheres and Solar-like Stellar Winds

Stellar analogs for the solar wind have proven to be frustratingly difficult to detect directly. However, these stellar winds can be studied indirectly by observing the interaction regions carved out by the collisions between these winds and the interstellar medium (ISM). These interaction regions are called "astrospheres", analogous to the "heliosphere" surrounding the Sun. The heliosphere and...

Axisymmetric Magnetized Winds and Stellar Spin - Downb