KIC 4552982: Outbursts and asteroseismology from the longest pseudo-continuous light curve of A ZZ Ceti

Keaton J. Bell, J. J. Hermes, A. Bischoff-Kim, Sean Moorhead, M. H. Montgomery, Roy �stensen, Barbara G. Castanheira, D. E. Winget

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Abstract

We present the Kepler light curve of KIC 4552982, the first ZZ Ceti (hydrogen-atmosphere pulsating white dwarf star) discovered in the Kepler field of view. Our data span more than 1.5 years, with a 86% duty cycle, making it the longest pseudo-continuous light curve ever recorded for a ZZ Ceti. This extensive data set provides the most complete coverage to date of amplitude and frequency variations in a cool ZZ Ceti. We detect 20 independent frequencies of variability in the data that we compare with asteroseismic models to demonstrate that this star has a mass . We identify a rotationally split pulsation mode and derive a probable rotation period for this star of 17.47 � 0.04 hr. In addition to pulsation signatures, the Kepler light curve exhibits sporadic, energetic outbursts that increase the star's relative flux by 2%-17%, last 4-25 hr, and recur on an average timescale of 2.7 days. These are the first detections of a new dynamic white dwarf phenomenon that may be related to the pulsations of this relatively cool ( K) ZZ Ceti star near the red edge of the instability strip.

Original languageEnglish (US)
Article number14
JournalAstrophysical Journal
Volume809
Issue number1
DOIs
StatePublished - Aug 10 2015

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All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Bell, K. J., Hermes, J. J., Bischoff-Kim, A., Moorhead, S., Montgomery, M. H., �stensen, R., Castanheira, B. G., & Winget, D. E. (2015). KIC 4552982: Outbursts and asteroseismology from the longest pseudo-continuous light curve of A ZZ Ceti. Astrophysical Journal, 809(1), [14]. https://doi.org/10.1088/0004-637X/809/1/14