Analysis of IUE spectra of helium-rich white dwarf stars

Author(s)
B G Castanheira, S O Kepler, Gerald Handler, D Koester
Abstract

We studied the class of DB white dwarf stars, using re-calibrated UV spectra for thirty four DBs obtained with the IUE satellite. By comparing the observed energy distributions with model atmospheres, we simultaneously determine spectroscopic distances (d), effective temperature (Teff), and surface gravities (log g). Using parallax measurements and previous determinations of Teff and log g from optical spectra, we can study whether the atmospheres of eleven DB stars are consistent with pure He or have a small amount of H contamination. We also report on our observations of seventeen stars with Teff close to the DB instability strip through time series photometry and found them to be non variable within our detection limits. Œ ESO 2006.

Organisation(s)
Department of Astrophysics
External organisation(s)
Universidade Federal do Rio Grande do Sul, Christian-Albrechts-Universität zu Kiel
Journal
Astronomy & Astrophysics
Volume
450
Pages
331-337
No. of pages
7
ISSN
0004-6361
Publication date
2006
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/9482d332-e07f-4dfd-89b4-06553072e9da