| Abstract | Calculations of the distance to the giant Sc galaxy M 101 are presented based on H II regions, angular sizes, brightest blue stars, cepheids, novae, supernovae, and luminosity-class calibrations. A mean value of 28.8 + or - 0.5 mag was determined, which is found to be inconsistent with the findings of Sandage and Tammann. It is concluded that the existence of the M 101 group of galaxies proposed by Sandage and Tammann, for use as secondary indicators, is questionable and their mean value is likely to be the upper limit of a wide interval of possible distances. |
