ZZ Canis Minoris is a symbiotic binary in the constellation Canis Minor. It is 4,000 light-years distant and is not visible to the naked eye with a maximum apparent magnitude of +9.7.
This binary system is made up of a red giant primary and a white dwarf secondary that is accreting material from the red giant. The accretion disk around the white dwarf and the collision of both components' stellar winds create X-ray emission. It does not show any silicon oxide (SiO) masers, nor an infrared excess that would identify it as a dusty symbiotic binary. The orbital period of the system is tentatively inferred to be 983 days.
The red giant primary is a semiregular variable, with an apparent magnitude that varies from 9.7 to 10.6 over an uncertain period, values of 106 and 437 days have been published. It has over 230 times the Sun's radius and is 5,350 times as luminous, radiating this energy from a cool, photosphere. It is on the asymptotic giant branch stage of its evolution, and is likely filling its roche lobe.
References Data about this star can be seen here.
ZZ Canis Minoris' database entry at VizieR.