[O-V] IN THE ULTRAVIOLET-SPECTRA OF GASEOUS NEBULAE

Theoretical O v electron-density-sensitive emission line ratios for R = I(2s(2 1)S(0) - 2s2p (3)p(2))/I(2s(2 1)S(0) -2s2p (3)p(1)) are prese nted. Inspection of Goddard High Resolution Spectrograph Hubble Space Telescope spectra of RR Tel reveals the presence of the [O v] 2s(2 1)s - 2s2p P-3(2) line at 1213.80 Angstrom which is 4.62 +/- 0.12 Angstro m away from the 2s(2 1)S -2s2p P-3(2) intercombination transition at 1 218.42 Angstrom, in good agreement with the theoretical prediction of Delta lambda = 4.54 Angstrom. The resultant value of R = 0.82 +/- O.11 implies a logarithmic electron density, log N-e, of 5.2 +/- 0.2 cm(-3 ) in good agreement with that found from other ions with high electron temperature, such as Ne VI which also provides support for the identi fication.