H_α intensity map of the Orion-Eridanus superbubble based on VTSS, SHASSA and WHAM data. The dashed line tracesthe perimeter of the present analysis. The white labels on the left hand side mark the key H_α features towards Orion. In the analysis region, the black contours delineate the main H I shells related to the superbubble, i.e the North Rim (N), South Loop (S), East Shell (E), and West Rim (W), and the Eridu cirrus (C) lying outside the superbubble (Joubaud et al. 2019). The molecular MBM 20 cloud (M)in front of the superbubble edge is outlined in white. The line of constant Galactic latitude b = −8° in the upper left corner indicates the orientation of the Galactic plane.