りゅう座BY型変光星
According to the system's entry in the Combined General Catalogue of Variable Stars, at least one of the components is a flare star and at least one is a BY Draconis variable. The white dwarf star GJ 630.1B, located 25.7 arcseconds away shares the same proper motion as the CM Draconis stars and is thus a true companion star of the system. Given the system's distance of 47 light years, this corresponds to a separation of at least 370 astronomical units between CM Draconis and GJ 630.1B.