The bright-star masks for the HSC-SSP survey

Understand

We present the procedure to build and validate the bright-star masks for the Hyper-Suprime-Cam Strategic Subaru Proposal (HSC-SSP) survey.

• To identify and mask the saturated stars in the full HSC-SSP footprint, we rely on the Gaia and Tycho-2 star catalogues.
• We first assemble a pure star catalogue down to $G_{\rm Gaia} < 18$ after removing $\sim1.5\%$ of sources that appear extended in the Sloan Digital Sky Survey (SDSS).
• We perform visual inspection on the early data from the S16A internal release of HSC-SSP, finding that our star catalogue is $99.2\%$ pure down to $G_{\rm Gaia} < 18$.