Components of the nebula surrounding CK Vul. (a) Optical hourglass nebula (orange and white) seen in the combined emission of Hα and [N II] lines (from Hajduk et al. 2013). Millimeter-wave emission of CO 1–0 is overlaid in cyan (from Kamiński et al. 2020). Green markers and labels show the characteristic velocities of these components. (b) Zoomed-in central portion of the components shown in (a). The structure of the optical nebula is seen more clearly. The red ellipse indicates the central region where many O-bearing molecules and strong dust emission are observed. The gray rectangle shows the region within the northern optical “jet” observed spectrally in the optical–near-infrared with X-shooter at a very high sensitivity (Tylenda et al. 2019). (c) The inset shows dispersed emission of a spectral line within the northern jet and illustrates that the emission is composed of at least three distinct morpho-kinematical components. (d) Combined emission of SiO (green), N₂H⁺ (blue), and mm-wave continuum define the molecular nebula (from Kamiński et al. 2020). The central region, bright in dust emission, is marked with a red ellipse.