Astronomers have assumed that the strong gravitational force exerted by black holes helps them capture any gaseous cloud that they can pull. When this happens, the region surrounding the hole shines brightly as the gas' gravitational energy is converted into heat. But some black holes are not as bright as others because they are not as effective at devouring gas clouds, say Roger Blandford of California Institute of Technology in Pasadena, USA, and his col- leagues. Martin Rees, Britain's Astronomer Royal, says he prefers the new model to the idea of an all-consuming black hole (New Scientist, Vol 159, No 2153).