Neutron star candidate. X-ray image of the binary star system Cygnus X-3 (bright object at centre). Cygnus X-3 probably consists of a star orbiting very close to a neutron star with a period of 4.8 hours. Gas from the outer layers of the \normal\" star is pulled outwards by the strong gravitational field of the neutron star. This material does not fall straight onto the neutron star but forms an accretion disc around it. The X- ray emission seen here comes from the gas in the disc which is heated up to some million of degrees by friction and dissipational processes. The image was taken by the ROSAT satellite. Additional information in Nature 355, pag. 680, February 1992."