CALIBRATION OF THE BRIGHTEST RED AND BLUE STARS AS DISTANCE INDICATORS FOR LATE-TYPE GALAXIES

Current data for 17 nearby galaxies are used to calibrate different fo rms of the brightest-star method. The relations between the distance m odulus, (m-M)(0), the total magnitude of the galaxy, B(g)(0), and the mean magnitudes of its three brightest red and blue stars, V(3R)(0) an d B(3B)(0), are (m-M)(0) = 3.73 - 0.38B(g)(0) + 1.40V(3R)(0); (m-M)(0) = 3.83 - 0.61B(g)(0) + 1.59B(3B)(0); (m-M)(0) = 3.60 - 0.45B(g)(0) 1.06V(3R)(0) + 0.40B(3B)(0). The results are applied to a sample of 15 other galaxies, including three presumed members of the Virgo cluster . The distance determination for Sextans B, IC 10, Ho II, Ho IX, NGC 4 523, and other galaxies is discussed. It is concluded that the method has a satisfactory accuracy ((m).3 - (m).4) and is reliable up to dist ances of the order of 20 Mpc.