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Ultraviolet spectra of planetary nebulae. IX. High-dispersion observations of NGC 7662.

Seaton, M. J.; Flower, D. R.; Penn, C. J.

High-dispersion IUE spectra of NGC 7662 have been obtained with exposure times optimized for measurement of the relative strengths of the components of: CIV lambda-lambda 1548, 1551; the forbidden line CIII lambda-lambda 1907, 1909 and the forbidden line Ne IV lambda-lambda 2422, 2424. The CIV ratio (lambda 1548)/(lambda 1551) is expected to be 2.…

Ultraviolet spectra of planetary nebulae. VIII. The C/O abundance ratio in the ring nebula.

Flower, D. R.

The Ring nebula (NGC 6720) has been observed with the International Ultraviolet Explorer satellite. Measurements of line intensities at a position on the ring, offset from the central star, lead to a value of the abundance ratio C/O approximately 1.2, a result which is insensitive to the adopted value of the electron temperature in the nebula.

Ultraviolet spectroscopy of phi Per.

Kitchin, C. R.

Ultraviolet observations at high dispersion of Phi Persei obtained on the IUE satellite are described. The interstellar lines are separated from the stellar and shell lines, and all the lines are identified. The velocity of the interstellar medium in the direction of Phi Per is estimated to be about 34 km/sec. A model of the system based on the ul…