The [Ne IV] ²D -> ⁴S lines in the planetary nebula NGC 7662.

Abstract

Results are reported for high-resolution IUE satellite observations of the 2p 3 2D 3/2 - 4S, 2D 5/2 - 4S UV forbidden lines of Ne IV in the spectrum of NGC 7662. Precision measurements of the wavelengths are obtained, along with an improved determination of Ne IV doublet-quartet separations, a measurement of the intensity ratio for the forbidden Ne IV lines, and velocity profiles for the 2D - 4S lines. A nebular expansion velocity of 20 + or - 3 km/s is measured for the 2D 3/2 - 4S forbidden line of Ne IV.