In 1902, William Wallace Campbell reported that η Geminorum A showed radial velocity variations. The assumption was that the star was a spectroscopic binary, although no period or other orbital parameters were determined. An orbit calculated in 1944 is essentially unchanged today, with a period of 2,983 days and an eccentricity of 0.53. Observations were made looking for sign of eclipses corresponding to the derived orbit, but the evidence was regarded as inconclusive. Due to the appearance of the spectrum, the spectroscopic companion is suspected to be a fainter M-class star.