Interstellar NA I D line studies of stars towards the Draco nebula.

New high-dispersion CCD spectra of sodium are presented for eight programme stars located in the direction of the ligh-latitude Draco molecular cloud. From the non-detection of interstellar Na I D absorption lines at the Draco H I velocity of −30 ≤ v LSR (H I) ≤ −13 km/s towards all stars a strict lower distance limit to the nebula of d > 300 pc (z > 180 pc) is derived. This distance determination is in line with results from former UBV photometric extinction measurements as well as from published star counts.