The case of NGC 6302: The impact of shocks in the derivation of Nitrogen
  abundances
  High nitrogen abundance is characteristic of Type I planetary nebulae as well
as their highly filamentary structure. In the present work we test the
hypothesis of shocks as a relevant excitation mechanism for a Type-I nebula,
NGC 6302, using recently released diagnostic diagrams to distinguish shocks
from photoexcitation. The construction of diagrams depends on emission line
ratios and kinematical information. NGC 6302 shows the relevance of shocks in
peripheral regions and the importance to the whole nebula. Using shocks, we
question the usual assumption of ICF calculation, justifying a warning to
broadly used abundance derivation methods. From a kinematical analysis, we
derive a new distance for NGC 6302 of $805\pm143\,$ pc.
