Wobble stumps Hubble in measuring distance of dwarf nova from Earth AUSTRALIAN astronomers have helped solve one of the cosmoss most thorny riddles  why one of the night skys most active twinklers behaves as if it was much closer. The SS Cygni star system is the brightest and best studied dwarf nova, according to a study reported today in the journal Science. It consists of a star orbiting a white dwarf  another star which has run out of fuel and collapsed into an extremely dense planet-sized object.