English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present a detailed analysis of time-resolved optical spectra of the ZZCeti white dwarf, HS 0507+0434B. Using the wavelength dependence of observedmode amplitudes, we deduce the spherical degree, l, of the modes, most of whichhave l=1. The presence of a large number of combination frequencies (linearsums or differences of the real modes) enabled us not only to test theoreticalpredictions but also to indirectly infer spherical and azimuthal degrees ofreal modes that had no observed splittings. In addition to the above, wemeasure line-of-sight velocities from our spectra. We find only marginalevidence for periodic modulation associated with the pulsation modes: at thefrequency of the strongest mode in the lightcurve, we measure an amplitude of2.6+/-1.0 km/s, which has a probability of 2% of being due to chance; for theother modes, we find lower values. Our velocity amplitudes and upper limits aresmaller by a factor of two compared to the amplitudes found in ZZ Psc. We findthat this is consistent with expectations based on the position of HS0507+0434B in the instability strip. Combining all the available informationfrom data such as ours is a first step towards constraining atmosphericproperties in a convectionally unstable environment from an observationalperspective.

Time-resolved optical spectroscopy of the pulsating DA white dwarf HS 0507+0434B