Resumen

RIESGO, H.  y  LOPEZ, J. A.. Revised Diagnostic Diagrams for Planetary Nebulae. Rev. mex. astron. astrofis [online]. 2006, vol.42, n.1, pp.47-51. ISSN 0185-1101.

Diagnostic diagrams of electron density-excitation for a sample of 613 planetary nebulae are presented. The present extensive sample allows the definition of new statistical limits for the distribution of planetary nebulae in the log [Hα/[S II]] versus log [Hα/[Nlog [Hα/[S II]] versus [SII] λλ 717/6731, and log [Hα/[S II]] versus [S II] λλ6717/6731 planes. The diagrams provide a good representation of the ranges of physical conditions, indicated by these emission line ratios, present in planetary nebulae during different evolutionary stages.

Palabras llave : ISM [PLANETARY NEBULAE].