Stability of the r-modes in white dwarf stars
Abstract
Stability of the r-modes in rapidly rotating white dwarf stars is investigated. Improved estimates of the growth times of the gravitational-radiation driven instability in the r-modes of the observed DQ Her objects are found to be longer (probably considerably longer) than 6x10^9y. This rules out the possibility that the r-modes in these objects are emitting gravitational radiation at levels that could be detectable by LISA. More generally it is shown that the r-mode instability can only be excited in a very small subset of very hot (T>10^6K), rather massive (M>0.9M_sun) and very rapidly rotating (P_min<P<1.2P_min) white dwarf stars. Further, the growth times of this instability are so long that these conditions must persist for a very long time (t>10^9y) to allow the amplitude to grow to a dynamically significant level. This makes it extremely unlikely that the r-mode instability plays a significant role in any real white dwarf stars.
Cite
@article{arxiv.gr-qc/9903042,
title = {Stability of the r-modes in white dwarf stars},
author = {Lee Lindblom},
journal= {arXiv preprint arXiv:gr-qc/9903042},
year = {2016}
}
Comments
5 Pages, 5 Figures, revtex