Spectra observed toward the HD 34078 star. Top: ¹²CO(1–0) (black) and ¹²CO(2–1) (blue) spectra observed at the IRAM-30 m telescope. The spectra are shown at their native resolution: 21.45′′ for ¹²CO(1–0) and 10.7′′ for ¹²CO(2–1). Bottom: Hybrid synthesis ¹²CO(1–0) spectrum obtained at an angular resolution of ~4.4′′. The best fit, made with two gaussian components, is shown in red. The derived quantities are shown in Table 2.