R Aquarii is a binary star system believed to contain a white dwarf and a Mira-type variable . The orbital period is approximately 44 years. The main Mira-type star is a red giant, and varies in brightness by a factor of several hundred and with a period of slightly more than a year; this variability was discovered by Karl Ludwig Harding in 1810. It has a distance of about 390 parsecs, and is one of the nearest symbiotic stars and a well-known jet source. The two components have been resolved at