SIMBAD references

The major purpose of this paper was to prove or disprove the nature of planetary nebula (PN) candidates in the northern hemisphere, taken from an internal list. We present spectroscopic observations and imaging of fifteen PNe, twelve of them identified for the first time. Another two candidates turned out to be an emission-line galaxy and an H II region. All observed PNe represent evolved stages, their angular diameter ranging from 8" to 90", and exhibit very low surface brightnesses. The three largest and faintest nebulae each host a central star of magnitude 18 to 20mag.