We have identified the 1.4 GHz radio source FIRST J102347.6+003841 (hereafter FIRST J1023+0038) with a previously unknown 17th-mag Galactic cataclysmic variable (CV). The optical spectrum resembles that of a magnetic (AM Herculis- or DQ Herculis-type) CV. Five nights of optical CCD photometry showed variations on timescales of minutes to hours, along with rapid flickering. A re-examination of the FIRST radio survey data reveals that the radio detection was based on a single 6.6 mJy flare; on two other occasions the source was below the ~1 mJy survey limit. Several other magnetic CVs are known to be variable radio sources, suggesting that FIRST J1023+0038 is a new member of this class (and the first CV to be discovered on the basis of radio emission). However, FIRST J1023+0038 is several optical magnitudes fainter than the other radio-detected magnetic CVs. It remains unclear whether the source simply had a very rare and extraordinarily intense radio flare at the time of the FIRST observation, or is really an unusually radio-luminous CV; thus further observations are urged.
@article{arxiv.astro-ph/0208383,
title = {FIRST J102347.6+003841: The First Radio-Selected Cataclysmic Variable},
author = {Howard E. Bond and Richard L. White and Robert H. Becker and M. Sean O'Brien},
journal= {arXiv preprint arXiv:astro-ph/0208383},
year = {2009}
}
Comments
4 pages, 3 figures; accepted for December 2002 issue of Publications of the Astronomical Society of the Pacific