Asteroseismology of the PG 1159 star PG 0122+200
نویسندگان
چکیده
منابع مشابه
ABELL 43 , a second pulsating “ hybrid - PG 1159 ” star ⋆
An abstract should be given e report observations of the planetary nebula nucleus Abell 43, obtained at the 2.5m Nordic Optical Telescope, which show that it is a pulsator. Abell 43, a " hybrid-PG 1159 " type star, is the second pulsator of this class, after HS 2324+3944. From the limited data set acquired, we find that Abell 43 exhibits at least two periods of 2600 s and 3035 s, the longest on...
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The archival spectrum of SDSS J212531.92-010745.9 shows not only the typical signature of a PG 1159 star, but also indicates the presence of a companion. With time-series photometry of SDSS J212531.92-010745.9 during 10 nights, spread over one month, with the Tübingen 80 cm and the Göttingen 50 cm telescopes, the binary nature of this object has recently been proven. An orbital period of 6.9 h ...
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We have performed soft X-ray spectroscopy of two hot white dwarfs with the Chandra observatory using the Low Energy Transmission Grating. The first target is the hot DA white dwarf LB1919 (T eff =69 000 K). This star is representative of a small group of hot DAs whose metallicities lie well below predictions from radiative levitation theory. The Chandra spectrum shows a rich absorption line spe...
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The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogen envelope, exposing the usuallyhidden intershell region. Thus, the photospheric elemental abundances of these stars allow to draw conclusions about details of nuclear burning and mixing processes in the pre...
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We present the results from 135 hours of nearly continuous time series photometry on the " hybrid " (H-rich) PG 1159 variable star HS 2324+3944, obtained in August– September 1997. The power spectrum of the data shows several frequencies (about 20 or more), concentrated in three narrow and very crowded regions near 475, 390 and 950 µHz in decreasing amplitude order. Most (if not all) of the pea...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2007
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20066295