This resource provides a compiled dataset of Galactic planetary nebulae derived from absolute optical spectroscopy and supplemented by selected values from the literature. Based on these data, fundamental physical parameters were calculated, including sizes, densities, electron temperatures, and central star characteristics.

The table includes:

• Object identifiers, excitation classes, and interstellar extinction at Hβ.
• Morphological and distance properties: angular diameters (Diam_arcsec), linear sizes (Diam_pc), and heliocentric distances (D_kpc).
• Electron densities from [SII] 6717/6731 ratios.
• Effective temperatures of central stars estimated both by the Zanstra method (T_HI) and empirical [OIII]-based calibrations (T0_[OIII], T1_[OIII]), given in units of 10**4 K.
• Timescales: duration of available observations (delta_t_obs_year) and model reproduction intervals (delta_t_model_year), linked to evolutionary models by Bertolami (2016, A&A 588, A25).
• Absolute emission-line fluxes for Hβ, HeII 4685, [OIII] 5007, Hα, [NII] 6583, HeI 6678, [SII] 6717/6731, HeI 7065, [ArIII] 7136, and [OI] 7324, with measurement uncertainties and (where relevant) a power-of-ten exponent.

Each measurement is provided in a machine-readable format, separating values, uncertainties, and exponents into dedicated columns. This ensures precise numerical handling and interoperability with Virtual Observatory services and pipelines.

• Emission nebulae
• Planetary nebulae
• Spectroscopy
• Optical observation