Contents

16 October 1992
Vol 258, Issue 5081

About The Cover

Representation of the entropy distribution in a nascent neutron star about 20 milliseconds after the collapsing core of its parent star stiffens and bounces. The shocked region experiences hydrodynamic instabilities that violate spherical symmetry and that may be central to the eventual understanding of supernovae and pulsars. See page 430. The entropy values span the spectrum from purple through blue and red, with the highest values represented by red; the black core shows the inner dense stable region. [Image: Adam Burrows and Bruce A. Fryxell]