CCD UBV photometry of stars in Sex A

Differences with the photometric scales of Sandage and Carlson (1985AJ.....90.1019S) and Hoessel et al. (1983ApJ...274..577H) are discussed; recalibration of the Sandage and Carlson data for Cepheids in Sextans A results in a smaller value for the distance modulus, {mu}=25.6. A similar value for the distance modulus is obtained from the colour-colour diagram.

Colour-colour and colour-magnitude diagrams for the whole galaxy and for different parts are presented indicating a general star formation activity all over Sextans A. The contribution of stars brighter than M_pg_=-3 to the total blue light of the galaxy amounts to 25%, a much higher value than what is found for other dwarf irregular galaxies in the Local Group. The integrated birthrate per unit mass of massive stars for the galaxy is found to be much higher than in the Magellanic Clouds, suggesting that the rate in Sextans A was probably smaller in the past.