Kitt Peak 12 m CO(2-1) channel maps together with the Spitzer 4.5 μm mosaic toward the south and southeastern regions of HB 3; (a) Spitzer 4.5 μm superposed on molecular CO integrated intensity contours over V_LST = −53 to −35 km s⁻¹. (b) CO integrated map (from −53 to −35 km s⁻¹), (c)–(f) = channel maps (Δ v = 0.65 km s⁻¹) centered at −51, −46, −41, and −35 km s⁻¹, respectively. The contours are those of integrated intensities at 20, 30, 40, 50 K km s⁻¹. The yellow box in (a) is mentioned in the text. The −35 km s⁻¹ CO clouds coincide with the observed H₂ emission at the southern (outer) shell. In frames (b)–(f), coordinate grids are shown at every 1^m 30^s in R.A. from 2^h 18^m to 2^h 22^m 30s and at every ﹩10^{\prime} ﹩ in decl. from + 61° ﹩40^{\prime} ﹩ to + 62° ﹩10^{\prime} ﹩. The CO image is centered on R.A. 2^h20^m17^s and decl. +61°55′37.5″ (J2000) with an FOV of 46.8′ × 42.8′.