Mass loss from central stars of planetary nebulae : the nucleus of NGC6543.
Abstract
Low and high resolution spectra of the nucleus of NGC 6543 were analyzed in the UV range (1150-3200 A). From the continuum energy distribution, the extinction towards this object was estimated to be E(B - V) = 0.08, and an effective temperature (80,000 K) was derived for the central star by comparison with pure-He model atmospheres for hot high gravity stars. The corresponding luminosity is roughly 4.18, the radius 0.64 solar radius, and the distance 1390 pc. From the analysis of the UV line profiles, the central star is estimated to be presently loosing mass with a rate of 320 million solar masses/yr with a terminal velocity of -1900 km/sec. There is also evidence that the supersonic wind is then decelerated and a circumstellar envelope is formed. The mass of the central star is projected to be 1.06 solar mass. The mass loss rate during the very last phase of the red giant progenitor must have been of the order of 1.5/100,000 solar mass per year. The comparison with recent evolutionary calculations indicates an initial mass for the progenitor of at least 5 solar masses.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 1986
- Bibcode:
- 1986A&A...169..227B
- Keywords:
-
- Planetary Nebulae;
- Stellar Evolution;
- Stellar Mass Ejection;
- Stellar Physics;
- Stellar Temperature;
- Astronomical Spectroscopy;
- Red Giant Stars;
- Stellar Envelopes;
- Stellar Winds;
- Ultraviolet Radiation;
- Astrophysics