HD 110067 is a wide hierarchical triple system

We report that HD 110067, the recently announced host star of a resonant sextuplet of transiting sub-Neptunes, is not a single star as claimed in the discovery paper, but a wide hierarchical triple. The K0 V planet hosting star (V = 8.4 mag, d = 32 pc) has a companion at a wide projected separation of 13400 au. This companion, namely HD 110106, is a slightly fainter (V = 8.8 mag) K3 V type 8-year period double-lined spectroscopic binary. The secondary in this spectroscopic binary is contributing a significant amount of flux and has a measured high mass ratio.