We have discovered periodic variations in the light curves of two hot DQ stars from the Sloan Digital Sky Survey, SDSS J220029.08-074121.5 and SDSS J234843.30-094245.3. These are the second and third variables detected among the hot DQs and confirm the existence of a new class of variable white dwarf stars. The amplitudes of the variations are one half as large as those detected in the first discovered variable, SDSS J142625.71+575218.3, and required high signal-to-noise photometry to detect. The pulse shapes of the stars are not like those of known white dwarf pulsators but are similar to the first hot DQ variable, SDSS J142625.71+575218.3.
@article{arxiv.0810.2140,
title = {Two New Variable Hot DQ Stars},
author = {B. N. Barlow and B. H. Dunlap and R. Rosen and J. C. Clemens},
journal= {arXiv preprint arXiv:0810.2140},
year = {2009}
}
Comments
Accepted for publication in ApJ Letters (14 pages, 5 figures, 2 tables)