Mode identification of Pulsating White Dwarfs using the HST

Abstract

We have obtained time-resolved ultraviolet spectroscopy for the pulsating DAV stars G226-29 and G185-32, and for the pulsating DBV star PG1351+489 with the Hubble Space Telescope Faint Object Spectrograph, to compare the ultraviolet to the optical pulsation amplitude and determine the pulsation indices. We find that for essentially all observed pulsation modes, the amplitude rises to the ultraviolet as the theoretical models predict for l=1 non-radial g-modes. We do not find any pulsation mode visible only in the ultraviolet, nor any modes whose phase flips by 180 degrees; in the ultraviolet, as would be expected if high l pulsations were excited. We find one periodicity in the light curve of G185-32, at 141 s, which does not fit theoretical models for the change of amplitude with wavelength of g-mode pulsations.

Accepted for publication in the Astrophysical Journal, Aug 2000

Cited by in corpus (28)

• Strange Quark Matter and Compact Stars
• Evolutionary and pulsational properties of white dwarf stars
• Toward ensemble asteroseismology of ZZ Ceti stars with fully evolutionary models
• Whole Earth Telescope observations of BPM 37093: a seismological test of crystallization theory in white dwarfs
• Seismological studies of ZZ Ceti stars. I. The model grid and the application to individual stars
• Observations of the pulsating subdwarf B star Feige 48: Constraints on evolution and companions
• Precision asteroseismology of the pulsating white dwarf GD 1212 using a two-wheel-controlled Kepler spacecraft
• Ultra-Dense Neutron Star Matter, Strange Quark Stars, and the Nuclear Equation of State
• Analysis of White Dwarfs with Strange-Matter Cores
• Detections and Constraints on White Dwarf Variability from Time-Series GALEX Observations
• Mode Identification from Combination Frequency Amplitudes in ZZ Ceti Stars
• HST and Optical Observations of Three Pulsating Accreting White Dwarfs in Cataclysmic Variables
• Analysis of IUE spectra of helium-rich white dwarf stars
• Nonlinear effects in time-resolved spectra of DAVs
• The Energy Dependence of Neutron Star Surface Modes and X-ray Burst Oscillations
• A Search for short-period Rocky Planets around WDs with the Cosmic Origins Spectrograph (COS)
• The Peculiar Pulsations of PY Vul
• FUSE observations of G226-29: First detection of the H_2 quasi-molecular satellite at 1150A
• A new look at the pulsating DB white dwarf GD 358:Line-of-sight velocity measurements and constraints on model atmospheres
• A puzzling periodicity in the pulsating DA white dwarf G 117-B15A
• Time-resolved FUSE Photometric and Spectroscopic Observations: PG1219+534, PG1605+072, and PG1613+426
• White Dwarf Variability with gPhoton: Pulsators
• NGTS and HST insights into the long period modulation in GW Librae
• Seismological Studies of Pulsating DA White Dwarfs Observed with the Kepler Space Telescope and K2 Campaigns 1-8
• The Heating and Pulsations of V386 Serpentis after its 2019 Dwarf Nova Outburst
• Collisional effects in the blue wing of Lyman-alpha
• UVSat: a concept of an ultraviolet/optical photometric satellite
• Seismic test of the mass-radius relationship of hydrogen-atmospheric white dwarf stars