Light Curve Patterns and Seismology of a White Dwarf with Complex Pulsation

نویسندگان

  • M. Paparó
  • P. A. Bradley
  • A. Bischoff - Kim
چکیده

The ZZ Ceti star KUV 02464+3239 was observed over a whole season at the mountain station of Konkoly Observatory. A rigorous frequency analysis revealed 6 certain periods between 619 and 1250 seconds, with no shorter period modes present. We use the observed periods, published effective temperature and surface gravity, along with the model grid code of Bischoff-Kim, Montgomery and Winget [1] to perform a seismological analysis. We find acceptable model fits with masses between 0.60 and 0.70 M⊙. The hydrogen layer mass of the acceptable models are almost always between 10−4 and 10−6 M∗. In addition to our seismological results, we also show our analysis of individual light curve segments. Considering the non-sinusoidal shape of the light curve and the Fourier spectra of segments showing large amplitude variations, the importance of non-linear effects in the pulsation is clearly seen.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

White Dwarf Seismology and the 12 C(α,γ) 16 O Rate

Recent determinations of the internal composition and structure of two helium-atmosphere variable white dwarf stars, GD 358 and CBS 114, have led to conflicting implied rates for the C(α, γ)O reaction. If we assume that both stars were formed through single-star evolution, then the initial analyses of their pulsation frequencies must have differed in some systematic way. I present improved fits...

متن کامل

ar X iv : a st ro - p h / 04 10 31 3 v 1 1 2 O ct 2 00 4 Seismology of Accreting White Dwarfs

Pulsation modes have recently been observed in a handful of white dwarf (WD) primaries of cataclysmic variables, allowing an interesting new probe into the structure of accreting WD's. We briefly discuss the seismology of these objects, how stellar properties may be inferred from the observed mode frequencies, and mode driving mechanisms. For one pulsator, GW Lib, we have shown that a WD mass M...

متن کامل

Seismology of pre-white dwarfs: Models for pulsating sdB stars

Two kinds of pre-white dwarf stars can be probed through asteroseismology: planetary nebula nuclei (PNNs) and sdB (EHB) stars. To exploit the observed pulsations requires models that incorporate state-ofthe-art input physics and realistic evolutionary histories. Pulsation analysis of extensive grids of such models provide self-consistent theoretical pulsation periods for comparison with observe...

متن کامل

Combination Frequencies in the Fourier Spectra of White Dwarfs

Combination frequencies are observed in the Fourier spectra of pulsating DA and DB white dwarfs. They appear at sums and differences of frequencies associated with the stellar gravity-modes. Brickhill (1992) proposed that the combination frequencies result from mixing of the eigenmode signals as the surface convection zone varying in depth when undergoing pulsation. This depth changes cause tim...

متن کامل

ar X iv : a st ro - p h / 03 03 56 3 v 1 2 5 M ar 2 00 3 High Resolution Spectroscopy of the Pulsating White Dwarf G 29 - 38

We present the analysis of time-resolved, high resolution spectra of the cool white dwarf pulsator, G 29-38. From measuring the Doppler shifts of the Hα core, we detect velocity changes as large as 16.5 km/s and conclude that they are due to the horizontal motions associated with the g-mode pulsations on the star. We detect seven pulsation modes from the velocity timeseries and identify the sam...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2009