A Far-Ultraviolet Spectroscopic Analysis of the Central Star of the Planetary Nebula Longmore 1
Abstract
We have performed a non-LTE spectroscopic analysis using far-UV and UV data of the central star of the planetary nebula K1-26 (Longmore 1) and found Teff=120+/-10 kK, logg=6.7+0.3-0.7 cm s-2, and Y~=0.10. The temperature is significantly hotter than previous results based on optical line analyses, highlighting the importance of analyzing the spectra of such hot objects at shorter wavelengths. The spectra show metal lines (from, e.g., carbon, oxygen, sulfur, and iron). The signatures of most elements can be fit adequately using solar abundances, confirming the classification of Lo 1 as a high-gravity O(H) object. Adopting a distance of 800 pc, we derive R*~=0.04 Rsolar, L~=250 Lsolar, and M~=0.6 Msolar. This places the object on the white dwarf cooling sequence of the evolutionary tracks with an age of τevol~=65 kyr.
Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer and data from the MAST archive. FUSE is operated for NASA by the Johns Hopkins University under NASA contract NAS 5-32985.- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- May 2004
- DOI:
- 10.1086/386380
- arXiv:
- arXiv:astro-ph/0402653
- Bibcode:
- 2004PASP..116..391H
- Keywords:
-
- planetary nebulae: individual (Lo 1);
- Stars: Atmospheres;
- stars: individual (Lo 1);
- Stars: AGB and Post-AGB;
- Stars: White Dwarfs;
- Astrophysics
- E-Print:
- 14 pages, 4 color figures. Accepted for publication in PASP