Recurrent Nova RS Ophiuci . ... Credit Copyright: John Chumack Explanation: This pretty star field in the constellation Ophiucus is centered on a star not often seen - RS Ophiuci. ... Such stars are now modeled as interacting binary star systems, composed of a compact white dwarf star co-orbiting with a swollen red giant. As material falls away from the red giant it collects in a rotating accretion disk before ultimately falling on to the white dwarf. ... NASA Official: Jay Norris. ...