New intrinsic-colour calibration for $uvby$--$\beta$ photometry

Yuksel Karatas, William J. Schuster

A new intrinsic-colour calibration ($(b$--$y{)}_o$--$\beta$) is presented for the $uvby$--$\beta$ photometric system, making use of re-calibrated Hipparcos parallaxes and published reddeni…