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Title: A NEW TIMESCALE FOR PERIOD CHANGE IN THE PULSATING DA WHITE DWARF WD 0111+0018

Abstract

We report the most rapid rate of period change measured to date for a pulsating DA (hydrogen atmosphere) white dwarf (WD), observed in the 292.9 s mode of WD 0111+0018. The observed period change, faster than 10{sup -12} s s{sup -1}, exceeds by more than two orders of magnitude the expected rate from cooling alone for this class of slow and simply evolving pulsating WDs. This result indicates the presence of an additional timescale for period evolution in these pulsating objects. We also measure the rates of period change of nonlinear combination frequencies and show that they share the evolutionary characteristics of their parent modes, confirming that these combination frequencies are not independent modes but rather artifacts of some nonlinear distortion in the outer layers of the star.

Authors:
; ;  [1];  [2]
  1. Department of Astronomy, University of Texas at Austin, Austin, TX - 78712 (United States)
  2. SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States)
Publication Date:
OSTI Identifier:
22167547
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 766; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COOLING; GALACTIC EVOLUTION; HYDROGEN; NONLINEAR PROBLEMS; PULSATING VARIABLE STARS; TIME DEPENDENCE; WHITE DWARF STARS

Citation Formats

Hermes, J. J., Montgomery, M. H., Winget, D. E., Mullally, Fergal, and Bischoff-Kim, A., E-mail: jjhermes@astro.as.utexas.edu. A NEW TIMESCALE FOR PERIOD CHANGE IN THE PULSATING DA WHITE DWARF WD 0111+0018. United States: N. p., 2013. Web. doi:10.1088/0004-637X/766/1/42.
Hermes, J. J., Montgomery, M. H., Winget, D. E., Mullally, Fergal, & Bischoff-Kim, A., E-mail: jjhermes@astro.as.utexas.edu. A NEW TIMESCALE FOR PERIOD CHANGE IN THE PULSATING DA WHITE DWARF WD 0111+0018. United States. https://doi.org/10.1088/0004-637X/766/1/42
Hermes, J. J., Montgomery, M. H., Winget, D. E., Mullally, Fergal, and Bischoff-Kim, A., E-mail: jjhermes@astro.as.utexas.edu. 2013. "A NEW TIMESCALE FOR PERIOD CHANGE IN THE PULSATING DA WHITE DWARF WD 0111+0018". United States. https://doi.org/10.1088/0004-637X/766/1/42.
@article{osti_22167547,
title = {A NEW TIMESCALE FOR PERIOD CHANGE IN THE PULSATING DA WHITE DWARF WD 0111+0018},
author = {Hermes, J. J. and Montgomery, M. H. and Winget, D. E. and Mullally, Fergal and Bischoff-Kim, A., E-mail: jjhermes@astro.as.utexas.edu},
abstractNote = {We report the most rapid rate of period change measured to date for a pulsating DA (hydrogen atmosphere) white dwarf (WD), observed in the 292.9 s mode of WD 0111+0018. The observed period change, faster than 10{sup -12} s s{sup -1}, exceeds by more than two orders of magnitude the expected rate from cooling alone for this class of slow and simply evolving pulsating WDs. This result indicates the presence of an additional timescale for period evolution in these pulsating objects. We also measure the rates of period change of nonlinear combination frequencies and show that they share the evolutionary characteristics of their parent modes, confirming that these combination frequencies are not independent modes but rather artifacts of some nonlinear distortion in the outer layers of the star.},
doi = {10.1088/0004-637X/766/1/42},
url = {https://www.osti.gov/biblio/22167547}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 766,
place = {United States},
year = {Wed Mar 20 00:00:00 EDT 2013},
month = {Wed Mar 20 00:00:00 EDT 2013}
}