Contents

20 March 1992
Vol 255, Issue 5051

About The Cover

Radiograph of the core of the Milky Way galaxy, ten light-years in extent, showing a new source—the Galactic Center Transient—within four light-years of the center (lower left). The radio emission from this source is thought to be a result of relativistic electrons spiraling in an intense magnetic field, which are probably from a system in which a neutron star or a black hole accretes material from its companion. See page 1538. [Image by J.-H. Zhao et al.]