Abstract
IN 1964, Aller and Faulkner1 reported the results of spectrophotometric observations of southern planetary nebulae carried out in 1960–61 using a spectrum scanner. In recent months, we have been engaged in the measurement of radial velocities of southern planetaries using a Newtonian spectrograph on the Radcliffe 74 inch telescope as previously described2. In the course of this work the emission lines were identified and visual line strengths assigned by estimation. Correlations between strength estimates in different spectra of the same object usually yield good results, permitting estimates of line strength to be converted from one spectrum to another. They do have the disadvantage that no allowance has been made for variation of spectral sensitivity of the emulsion used (103a–O) or for various sources of absorption in the sky and the instruments, or for exposure time.
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References
Aller, L. H., and Faulkner, D. J., The Galaxy and the Magellanic Clouds, IAU–URSI Symposium No. 20, 45 (1964).
Evans, David S., Mon. Not. Astro. Soc. Southern Africa, 22, 140 (1963).
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EVANS, D., CATCHPOLE, R. & JONES, D. Short-term Variations in Line Strengths of Planetary Nebulae. Nature 220, 249 (1968). https://doi.org/10.1038/220249a0
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DOI: https://doi.org/10.1038/220249a0
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