(Left) a) composite colour image of Sh 2-217 in the optical. Pink is for Hα (6563 Å), turquoise is for the [SII] emission (λλ   6717−6731 Å). The images were obtained with the 120-cm telescope at the Observatoire de Haute Provence (OHP; exposure times 1 h and 2 h, respectively). The field is  ~10 × 11 arcmin². North is up, east is left. The arrow indicates the exciting star. The box outlines the field seen on the right. (Right) b) composite colour image of the cluster on the SW edge of Sh 2-217. Red and green are for the emission in the K- and H-bands, respectively, and blue is for the Hα emission. The near-IR frames were obtained at the 3.58-m Telescopio Nazionale Galileo; the Hα at the OHP. The top arrow indicates a very red star, which will be discussed in Sect. 4.5; the lower arrow points to a jet/outflow (seen as a reddish streak; see Sects. 4.4 and 4.5).