Observations of Southern Planetary Nebulae
Abstract
An Ha survey of the entire southern sky south of -25 declination with the Mount Wilson 10-inch objective- rism camera has resulted in a catalogne of 459 objects classifiable as planetary nebulae or possible p anetary nebulae. Of these, approximately 150 are newly discovered. The catalogne gives for both old and new nebulae basic data including intensity of the Ha image, intensity of the continuum, degree of resolution of the Ha image, and presence of emission lines other than Ha. Where possible, nebular diameter and the intensity ratio of [N ii] X6584 to Ha are also listed. Since one of the more significant features of this catalogne is its broad coverage and its uniformity, a careful study of its purity and completeness has been made. The surface distribution of these nebulae shows, in addition to the well-known concentration toward the galactic center, significant concentrations in Norma and Crux. An analysis of the frequency of [N n] shows that 22 per cent of the nebulae which might show [N ii] have [N ii]/Ha ratios greater than 0.5, 22 per cent have ratios between 0.1 and 0.5, and 56 per cent show no [N ii].
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- April 1967
- DOI:
- 10.1086/190151
- Bibcode:
- 1967ApJS...14..125H