Pulsations of the Low Mass Zz Ceti Star Hs 1824+6000

Abstract

Measuring g-mode pulsations of isolated white dwarfs can reveal their interior properties to high precision. With a spectroscopic mass of ≈ 0.51M⊙ (logg = 7.82), the DAV white dwarf HS 1824+6000 is near the transition between carbon/oxygen core and helium core white dwarfs, motivating our photometric search for additional pulsations from the Palomar 60-inch telescope. We confirmed (with much greater precision) the three frequencies: 2.751190± 0.000010 mHz (363.479 sec), 3.116709± 0.000006 mHz (320.851 sec), 3.495113± 0.000009 mHz (286.114 sec), previously found by B. Voss and collaborators, and found an additional pulsation at 4.443120± 0.000012 mHz (225.067 sec). These observed frequencies are similar to those found in other ZZ Ceti white dwarfs of comparable mass (e.g. logg < 8). We hope that future observations of much lower mass ZZ Ceti stars (< 0.4M⊙) will reveal pulsational differences attributable to a hydrogen covered helium core. Subject headings: stars: white dwarfs— stars: oscillations— stars: individual: HS 1824+6000

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Cite this paper

@inproceedings{STEINFADT2008PulsationsOT, title={Pulsations of the Low Mass Zz Ceti Star Hs 1824+6000}, author={JUSTIN D. R. STEINFADT and Shri R. Kulkarni}, year={2008} }