Ultraviolet spectra of planetary nebulae
Abstract
The ultraviolet spectra of the planetary nebulae for which spaceborne measurements are available are examined. Ultraviolet spectrograms of the nebulae IC 2149 and NGC 7027 and 7662 were obtained by the Orion-2 observatory on the Soyuz 13 spacecraft and electronographic equipment on board the Aerobee rocket, respectively, with wideband UV photometry of other nebulae available from the OAO-2 and ANS satellite observatories. The shortwave spectra of IC 2149 and NGC 7027 are discussed in detail and it is noted that the ultraviolet spectra of these nebulae which belong to different excitation classes differ more than do their optical spectra. A measurement of the continuous spectrum of the central star of IC 2149 is presented and the interstellar reddening effect observed in wideband short-wave photometry of planetary nebulae is pointed out. Continuous ultraviolet spectra of nebulae and the role of two-photon hydrogen emission in planetary nebula ultraviolet spectra are discussed, and a method for determining the radius of the central star is proposed.
- Publication:
-
Vistas in Astronomy
- Pub Date:
- 1979
- DOI:
- 10.1016/0083-6656(79)90007-2
- Bibcode:
- 1979VA.....23...45G
- Keywords:
-
- Astronomical Spectroscopy;
- Planetary Nebulae;
- Short Wave Radiation;
- Ultraviolet Astronomy;
- Ultraviolet Spectra;
- Broadband;
- Continuous Spectra;
- Emission Spectra;
- Photons;
- Astrophysics