Number 122 (Story #3), April 6, 1993 by Phillip F. Schewe and Ben Stein IN THE STARBURST MODEL , quasar energy derives from the concerted birth and then death (by supernova) of supermassive stars, first with a generation of 25-60-solar-mass stars and later with the explosion of more numerous but somewhat smaller stars, all within a 10-million year period. First proposed in 1960s but eclipsed by the model which holds that black holes fuel quasar emissions, the starburst model is making a comeback, according to Roberto Terlevich of the Royal Greenwich Observatory and Brian Bayle of Cambridge (UK), who have been making a survey of quasar brightnesses. Opponents of the theory, such as Martin Rees of Cambridge, argue that star energy alone could not account for the brightness of quasars. (Science, 19 Mar.)