... Star Atlas . ... stars . ... Astronomers close in on cause of stellar explosions . ... RELATED TOPICS: STARS | ... If a star system contains two white dwarfs, then the white dwarfs revolve around one another at 0.5 million mph (0.8 million km/h), speeding up and getting closer and closer until one day they merge, most likely producing the fireworks of a type Ia supernova. т??There are reasons to suspect that type Ia supernovae come from the merging of a double white dwarf,т?? ... Where are the stars...