papers

Publications (12)

astro-ph2006

High-resolution ultraviolet spectroscopy of PG1159-035 with HST and FUSE

D. Jahn, T. Rauch, E. Reiff +3

PG1159-035 is the prototype of the PG1159 spectral class which consists of extremely hot hydrogen-deficient (pre-) white dwarfs. It is also the prototype of the GW Vir variables, w…

astro-ph2008

UV and FUV spectroscopy of the hybrid PG 1159-type central star NGC 7094

M. Ziegler, T. Rauch, E. Reiff +3

Previous studies aiming at the iron-abundance determination in three PG 1159 stars (K 1-16, PG 1159-035, NGC 7094) and a [WC]-PG 1159 transition star (Abell 78) have revealed that…

astro-ph2007

A new period determination for the close PG1159 binary SDSSJ212531.92-010745.9

S. Schuh, I. Traulsen, T. Nagel +6

Methods to measure masses of PG1159 stars in order to test evolutionary scenarios are currently based on spectroscopic masses or asteroseismological mass determinations. One recent…

astro-ph2006

AGB star intershell abundances inferred from analyses of extremely hot H-deficient post-AGB stars

K. Werner, D. Jahn, T. Rauch +3

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 t…

astro-ph2004

FUSE spectroscopy of PG1159 Stars

E. Reiff, T. Rauch, K. Werner +1

PG1159 stars are hot hydrogen-deficient post-AGB stars with effective temperatures within a range from 75000 K up to 200000 K. These stars are probably the result of a late helium-…

astro-ph2005

Light and heavy metal abundances in hot central stars of planetary nebulae

K. Werner, A. I. D. Hoffmann, D. Jahn +5

We present new results from our spectral analyses of very hot central stars achieved since the last IAU Symposium on planetary nebulae held in Canberra 2001. The analyses are mainl…

astro-ph2008

2006 Whole Earth Telescope Observations of GD358: A New Look at the Prototype DBV

J. L. Provencal, M. H. Montgomery, A. Kanaan +53

We report on the analysis of 436.1 hrs of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 200…

astro-ph2008

O(He) Stars

T. Rauch, E. Reiff, K. Werner +1

Spectral analyses of H-deficient post-AGB stars have shown that a small group of four extremely hot objects exists which have almost pure He absorption-line spectra in the optical.…

astro-ph2007

Elemental Abundances in PG1159 Stars

K. Werner, T. Rauch, E. Reiff +1

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 t…

astro-ph2008

Search For Iron, Nickel, and Fluorine in PG1159 Stars

E. Reiff, T. Rauch, K. Werner +2

A possible origin of the iron-deficiency in PG1159 stars could be neutron captures on Fe nuclei. A nickel overabundance would corroborate this idea. Consequently we are looking for…

astro-ph2004

Identification of neon in FUSE and VLT spectra of extremely hot hydrogen-deficient (pre-) white dwarfs

K. Werner, T. Rauch, E. Reiff +2

One of the strongest absorption lines observed in far-ultraviolet FUSE spectra of many PG1159 stars remained unidentified up to now. We show that this line, located at 973.3A, stem…

astro-ph2006

NLTE spectral analysis of GW Vir pulsators

E. Reiff, D. Jahn, T. Rauch +3

GW Vir variables are the pulsating members in the spectroscopic class of PG 1159 stars. In order to understand the characteristic differences between pulsating and non-pulsating PG…