Leo A - Color-magnitude diagram of its brightest stars

The color-magnitude diagram for the bright stars of the dwarf irregular galaxy Leo A is presented. Plates obtained with the CFH telescope were measured with the APM system at Cambridge. No secondary images are used for the faint-magnitude calibration. Leo A has a population of bright blue stars, but no bright red supergiants at the same magnitude level are present. A distance of 2.3 Mpc is determined from the apparent magnitude of its brightest blue stars. Leo A with M(v) = -14.4 has the same brightness as Sextans A. Leo A is, however, bluer. Very recent star formation could explain the morphology of its color-magnitude diagram.