Issue |
A&A
Volume 499, Number 1, May III 2009
|
|
---|---|---|
Page(s) | 257 - 266 | |
Section | Stellar structure and evolution | |
DOI | https://doi.org/10.1051/0004-6361/200810727 | |
Published online | 30 March 2009 |
Asteroseismology of hot pre-white dwarf stars: the case of the DOV stars PG 2131+066 and PG 1707+427, and the PNNV star NGC 1501
1
Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, (1900) La Plata, Argentina e-mail: [acorsico;althaus;mmiller]@fcaglp.unlp.edu.ar
2
Instituto de Astrofísica La Plata, IALP, CONICET-UNLP, Argentina
3
Member of the Carrera del Investigador Científico y Tecnológico, CONICET, Argentina
4
Fellow of CONICET, Argentina
5
Departament de Física Aplicada, Escola Politècnica Superior de Castelldefels, Universitat Politècnica de Catalunya, Av. del Canal Olímpic, s/n, 08860 Castelldefels, Spain e-mail: garcia@fa.upc.edu
6
Institute for Space Studies of Catalonia, c/Gran Capità 2–4, Edif. Nexus 104, 08034 Barcelona, Spain
Received:
31
July
2008
Accepted:
26
March
2009
Aims. We present an asteroseismological study on the two high-gravity pulsating PG 1159 (GW Vir or DOV) stars, PG 2131+066 and PG 1707+427, and on the pulsating [WCE] star NGC 1501. All of these stars have been intensively scrutinized through multi-site observations, so they have well resolved pulsation spectra.
Methods. We compute adiabatic g-mode pulsation periods on PG 1159
evolutionary models with stellar masses ranging from 0.530
to . These models take into account the
complete evolution of progenitor stars, through the
thermally pulsing AGB phase, and born-again episode. We
constrain the stellar mass of PG 2131+066, PG 1707+427, and NGC 1501 by
comparing the observed period spacing with the asymptotic
period spacing and with the average of the computed period
spacings. We also employ the individual observed periods
in search of representative seismological models for each
star.
Results. We derive a stellar mass of for PG 2131+066,
for PG 1707+427, and
for
NGC 1501 from a comparison between the observed period spacings
and the computed asymptotic period spacings, and a stellar
mass of
for PG 2131+066,
for
PG 1707+427, and
for NGC 1501 by comparing the
observed period spacings with the average of the computed
period spacings. We also find, on the basis of a period-fit
procedure, asteroseismological models representatives of
PG 2131+066 and PG 1707+427. These best-fit models are able to reproduce
the observed period patterns of these stars with an average
of the period differences of
s and
s, respectively. The
best-fit model for PG 2131+066 has an effective temperature
K, a stellar mass
, a
surface gravity
, a stellar luminosity and
radius of
and
, respectively, and a He-rich
envelope thickness of
. We derive a seismic distance
pc and
a parallax
mas. The best-fit model for PG 1707+427,
on the other hand, has
K,
,
,
,
, and
, and the seismic distance and
parallax are
pc and
mas.
Finally, we have been unable to find an unambiguous best-fit
model for NGC 1501 on the basis of a period-fit procedure.
Conclusions. This work closes our short series of asteroseismological studies on pulsating pre-white dwarf stars. Our results demonstrate the usefulness of asteroseismology for probing the internal structure and evolutionary status of pre-white dwarf stars. In particular, asteroseismology is able to determine stellar masses of PG 1159 stars with an accuracy comparable or even better than spectroscopy.
Key words: stars: evolution / stars: interiors / stars: oscillations / white dwarfs
© ESO, 2009
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.