The K2 Bright Star Survey ("halo")

The HALO project produces calibrated light curves of stars from K2 that are brighter than the saturation limit of the detector (~11th magnitude). Light curves of 161 bright stars from K2 Campaign 4 and onwards are provided, derived from the unsaturated scattered-light "halo" around the stars. Light curve creation relies on optimizing the weights of a linear combination of the pixel time series using a lagged Total Variation minimization, which is demonstarted to work on both saturated and unsaturated K2 targets. After flux extraction from the halo apertures, the light curves are further corrected using the "k2sc" Gaussian Process systematics-correction code to further correct pointing residuals.