The innermost system is a single-lined spectroscopic binary with an orbital period of 2.55 years and an eccentricity of 0.44.[4] The orbital plane of this pair is being viewed nearly edge-on, and has an angular semimajor axis of 9.5″.[4] A third member of the system has a poorly-constrained 420 year orbit around the main pair.[10] This star was discovered by Burnham in 1874,[5] and the discovery code BU 290 was given to the double. As of 2015, it lies at an angular separation of 3.90±0.02 along a position angle of 226.2°±0.8° from the inner system.[7]
The secondary companion to the primary, component Ab, is most likely a red dwarf[5] star with around 29% of the mass of the Sun.[4] The tertiary member, component B, has 53%[11] of the Sun's mass and a class of around K4.[5]
^ abHouk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
^ abcdeGriffin, R. F. (February 2010), "Spectroscopic binary orbits from photoelectric radial velocities - Paper 210: Psi2 Aurigae and 34 Pegasi", The Observatory, 130 (1): 17–32, Bibcode:2010Obs...130...17G.