05 January 2001
Vol 291, Issue 5501

About The Cover

Cover image expansion

COVER Production of an astrophysical jet by magnetic forces during gravitational contraction of a rotating, ionized torus (yellow material) as it accretes onto a central compact object. High-speed, spinning bipolar outflow (green) is generated by torsional Alfvén waves that propagate along the large-scale magnetic field (red). These waves simultaneously pinch the magnetic field into slender jets. See page 84 [Image: Y. Uchida, M. Nakamura, S. Hirose]