White dwarfs correspond to the final stages of stellar evolution ofsolar-type stars. In these objects, production of energy by nuclear burning hasended which means that a white dwarf simply cools down over the course of thenext billion years. It is now known that white dwarfs spend some of theircooling history in an instability strip. The pulsating white dwarfs with anhydrogen atmosphere (called DAV or ZZ Ceti stars) show non-radial oscillationmodes with periods in the range 100 - 1200s. In this work we try to illustratehow the oscillation p-mode frequencies of idealized white dwarf models changeas the result of a different chemical composition in the core, with theultimate goal of determining the chemical stratification from seismicobservations. The presence of acoustic glitches in the internal structureresults in a periodic signal in the frequencies. We find that this signaldepends on the chemical stratification/composition of the core in a form thatcan be analytically modelled.
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