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arXiv · 1511.07258

Direct Detection of the L-Dwarf Donor in WZ Sagittae

Thomas E. Harrison
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Abstract

Analysis of a large set of phase-resolved $K$-band spectra of the cataclysmic variable WZ Sge shows that the secondary star of this system appears to be an L-dwarf. Previous $K$-band spectra of WZ Sge found that the CO overtone bandheads were in emission. We show that absorption from the $^{\rm 12}$CO$_{\rm (2,0)}$ bandhead of the donor star creates a dip in the $^{\rm 12}$CO$_{\rm (2,0)}$ emission feature. Measuring the motion of this feature over the orbital period, we construct a radial velocity curve that gives a velocity amplitude of K$_{\rm abs}$ = 520 $\pm$ 35 km s$^{\rm -1}$, consistent with the previously published values for this parameter.

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Thomas E. Harrison. 2015-11-23. Direct Detection of the L-Dwarf Donor in WZ Sagittae. https://doi.org/10.3847/0004-637x%2F816%2F1%2F4

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