Into the Depths: A New Activity Metric for High-precision Radial Velocity Measurements Based on Line Depth Variations

  title={Into the Depths: A New Activity Metric for High-precision Radial Velocity Measurements Based on Line Depth Variations},
  author={Jared C. Siegel and Ryan A. Rubenzahl and Samuel P. Halverson and Andrew W. Howard},
  journal={The Astronomical Journal},
The discovery and characterization of extrasolar planets using radial velocity (RV) measurements is limited by noise sources from the surfaces of host stars. Current techniques to suppress stellar magnetic activity rely on decorrelation using an activity indicator (e.g., strength of the Ca ii lines, width of the cross-correlation function, broadband photometry) or measurement of the RVs using only a subset of spectral lines that have been shown to be insensitive to activity. Here, we combine… 



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