THE CHEMICAL-COMPOSITIONS OF THE SRD VARIABLE-STARS - I - XY-AQUARII,RX-CEPHEI, AB-LEONIS, AND SV-URSAE-MAJORIS

Chemical compositions are derived from high-resolution spectra for fou r stars classed as SRd variables in the General Catalogue of Variable Stars. Two stars-XY Aquarii and RX Cephei-are of solar metallicity and most likely not variable stars. Their spectroscopic effective tempera tures and surface gravities correspond to the spectral types G0V for X Y Aqr and G8 III for RX Cep. Two stars are undisputed variables and sh own here to be metal-poor supergiants: AB Leonis with [Fe/H] similar o r equal to -1.6 and SV Ursae Majoris with [Fe/H] similar or equal to - 1.4. The metallicities and high radial velocities show them to be halo stars.