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. Homeier61 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
(
K,
) is located near the red edge of the
ZZ Ceti instability strip, whereas HE 1429-0343 (
K,
) 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