2002A&A...388..219K


C.D.S. - SIMBAD4 rel 1.7 - 2020.02.24CET01:27:57

2002A&A...388..219K - Astronomy and Astrophysics, volume 388, 219-234 (2002/6-2)

Time-resolved optical spectroscopy of the pulsating DA white dwarf HS 0507+0434B. New constraints on mode identification and pulsation properties.

KOTAK R., VAN KERKWIJK M.H. and CLEMENS J.C.

Abstract (from CDS):

We present a detailed analysis of time-resolved optical spectra of the ZZ Ceti white dwarf, HS 0507+0434B. Using the wavelength dependence of observed mode amplitudes, we deduce the spherical degree, l, of the modes, most of which have l=1. The presence of a large number of combination frequencies (linear sums or differences of the real modes) enabled us not only to test theoretical predictions but also to indirectly infer spherical and azimuthal degrees of real modes that had no observed splittings. In addition to the above, we measure line-of-sight velocities from our spectra. We find only marginal evidence for periodic modulation associated with the pulsation modes: at the frequency of the strongest mode in the lightcurve, we measure an amplitude of 2.6±1.0km/s, which has a probability of 2% of being due to chance; for the other modes, we find lower values. Our velocity amplitudes and upper limits are smaller by a factor of two compared to the amplitudes found in ZZ Psc. We find that this is consistent with expectations based on the position of HS 0507+0434B in the instability strip. Combining all the available information from data such as ours is a first step towards constraining atmospheric properties in a convectionally unstable environment from an observational perspective.

Abstract Copyright:

Journal keyword(s): stars: individual: HS 0507+0434, ZZ Psc - white dwarfs - oscillations - convection

Simbad objects: 7

goto Full paper

goto View the reference in ADS

Number of rows : 7

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 V* ZZ Cet WD* 01 36 13.6155835488 -11 20 32.631811638   14.328 14.16 14.4   DA4.0 258 0
2 HS 0507+0434B WD* 05 10 13.5216587720 +04 38 55.134907779   15.52 15.31 15.63   DA2.3 50 0
3 HS 0507+0434A WD* 05 10 13.9441055186 +04 38 38.433188110   14.14 14.22 14.46   DA4.1 19 0
4 V* RY LMi WD* 09 24 15.2484202569 +35 16 51.400826911   15.72   15.99   DA4 247 0
5 V* GW Vir WD* 12 01 45.9728868858 -03 45 40.627851273   14.87 15.04     DOQZ1 460 0
6 GD 358 WD* 16 47 18.3926893312 +32 28 32.865420612 12.511 13.530 13.653 13.752 13.852 DB2 314 0
7 V* ZZ Psc WD* 23 28 47.6364608228 +05 14 54.234982405   13.17   13.0   DA4.1 424 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2002A&A...388..219K and select 'bookmark this link' or equivalent in the popup menu


2020.02.24-01:27:57

© Université de Strasbourg/CNRS

    • Contact