THE ELM SURVEY. I. A COMPLETE SAMPLE OF EXTREMELY LOW-MASS WHITE DWARFS

@article{Brown2010THEES,
  title={THE ELM SURVEY. I. A COMPLETE SAMPLE OF EXTREMELY LOW-MASS WHITE DWARFS},
  author={Warren R. Brown and Mukremin Kilic and Carlos Allende Prieto and Scott J. Kenyon},
  journal={The Astrophysical Journal},
  year={2010},
  volume={723},
  pages={1072 - 1081}
}
We analyze radial velocity observations of the 12 extremely low-mass (ELM), with ⩽0.25 M☉, white dwarfs (WDs) in the MMT Hypervelocity Star Survey. Eleven of the twelve WDs are binaries with orbital periods shorter than 14 hr; the one non-variable WD is possibly a pole-on system among our non-kinematically selected targets. Our sample is unique: it is complete in a well-defined range of apparent magnitude and color. The orbital mass functions imply that the unseen companions are most likely… 

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