EDP Sciences
Free Access
Issue
A&A
Volume 443, Number 1, November III 2005
Page(s) 195 - 199
Section Stellar structure and evolution
DOI https://doi.org/10.1051/0004-6361:20053362


A&A 443, 195-199 (2005)
DOI: 10.1051/0004-6361:20053362

Two new ZZ Ceti pulsators from the HS and HE surveys

R. Silvotti1, B. Voss2, I. Bruni3, D. Koester2, D. Reimers4, R. Napiwotzki5 and D. Homeier6

1  INAF - Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy
    e-mail: silvotti@na.astro.it
2  Institut für Theoretische Physik und Astrophysik der Universität Kiel, Leibnizstraße 15, 24098 Kiel, Germany
    e-mail: voss@astrophysik.uni-kiel.de,koester@astrophysik.uni-kiel.de
3  INAF - Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy
    e-mail: ivan.bruni@bo.astro.it
4  Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany
    e-mail: dreimers@hs.uni-hamburg.de
5  Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK
    e-mail: r.napiwotzki@star.herts.ac.uk
6  Institut für Astrophysik, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
    e-mail: derek@astro.physik.uni-goettingen.de

(Received 3 May 2005 / Accepted 9 June 2005 )

Abstract
We report the detection of nonradial g-mode oscillations in the DA white dwarfs HS 1039+4112 (B=15.9) and HE 1429-0343 (B=15.8) from time-series photometry made at the Loiano 1.5 m telescope. The two stars were previously selected as probable pulsators based on two-color photometry and spectral analysis respectively. Following our temperature and surface gravity determinations, HS 1039+4112 ( $\mbox{$T_{\rm eff}$ } = 11\,200$ K, $\mbox{$\log g$ } =8.2$) is located near the red edge of the ZZ Ceti instability strip, whereas HE 1429-0343 ( $\mbox{$T_{\rm eff}$ }=11\,400$ K, $\mbox{$\log g$ }=7.8$) falls in the middle of the strip. Both stars show a multi-mode behavior with the main periods at about 850 and 970 s respectively, and relatively large amplitudes (~7% and ~2.5%).


Key words: stars: white dwarfs -- stars: oscillations -- stars: individual: HS 1039+4112, HE 1429-0343

SIMBAD Objects



© ESO 2005

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.