Fig. 1

Observed central stars of planetary nebulae listed in Table 1. Left panels show the stars observed with FORS2 at UT2. Right panels show the stars observed with ISIS at WHT. Low panels show the logarithmic relative intensity for those stars dominated by emission lines. An ad hoc shift has been assumed to avoid the overlapping of spectra.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.