G 107-69/70

G 107-69/70 is a quadruple system, consisting of the astrometric binary G 107-69 and the resolved binary G 107-70. The system is 36.76 light years (11.27 parsecs) from Earth. G 107-69 and G 107-70 are separated by 103.2 arcseconds, or 1163 astronomical units (AU).

G 107-69A is a red dwarf star with a spectral type of M4.5 and a mass of about. G 107-69B has a mass of about or. The binary has a period of 0.94 years and a predicted separation of about $-56.486$. From its mass G 107-69B could be either a low-mass red dwarf star or a brown dwarf.

G 107-70 (also called WD 0727+482) is a pair of white dwarfs, with both having similar mass, brightness and atmospheric composition. The binary was first partially resolved in 1976. Later Nelan et al. fully resolved the orbit of this binary with Hubble's Fine Guidance Sensor and found an orbital period of $-201.282$ and a semi-major axis of $-1,272.162$. At a distance of 11.27 parsecs the semi-major axis is about $3,200$.

By resolving the orbit of the G 107-70 system Nelan et al. were able to calculate the dynamical mass of each component: G 107-70A has a mass of $-0.15$ and G 107-70B has a mass of $5$. Both white dwarfs have a spectral type of DA, which indicates an atmosphere dominated by hydrogen.