Of apparent magnitude 4.06, Upsilon Boötis has a spectral class of K5 and an absolute magnitude of −0.3. Dimmer than Upsilon Boötis is magnitude 4.54 Phi Boötis, with a spectral class of K2 and an absolute magnitude of −0.1. Just slightly dimmer than Phi at magnitude 4.60 is O Boötis, which, like Izar, has a spectral class of K0. O Boötis has an absolute magnitude of 0.2. The other four dim stars are magnitude 4.91 6 Boötis, class K4; magnitude 4.86 20 Boötis, class K3; magnitude 4.81 Omega Boötis, class K4; and magnitude 4.83 A Boötis, class K1.
