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astro-ph1999
Measurements of 12C/13C ratio in planetary nebulae: implications on stellar and Galactic chemical evolution
F. Palla, R. Bachiller, L. Stanghellini +2
We present the results of a study aimed at determining the 12C/13C ratio in two samples of planetary nebulae (PNe) by means of millimeter wave observations of 12CO and 13CO. The fi…
astro-ph1999
Magellanic Cloud Planetary Nebulae: A Fresh Look at the Relations between Nebular and Stellar Evolution
L. Stanghellini, R. A. Shaw, J. C. Blades +1
Studies of the relationship between planetary nebula morphology and the evolution of the central stars has long suffered from uncertainties in distance determinations, and from the…