Brightest stars in the Small Magellanic Cloud

Photometric observations on the uvby system of the 169 luminous stars in Sanduleak's finding list for the SMC have been made along with Hfl measures of all his stars brighter than V = 12 and some representative fainter ones. The color-magnitude diagram shows a deficiency of very luminous stars near spectral type mid-F which is not present in the LMC. The program stars are too numerous to be evolving on a Kelvin time scale; and if the hotter evolved stars have the temperatures indicated by model atmospheres, they must be in the later stages of helium burning. The m1 index is shown to be useful for identifying stars with Of emission features as well as Wolf-Rayet stars. The strength of the emission features, when present, in the former increases with luminosity. The distance modulus of the SMC found from the Hfl-c0-M relation in NGC 6231 and in h and x Per is somewhat smaller than that given by the Cepheids, in accord with other studies based on the hydrogen lines. The reddening near the supergiant stars in the SMC is variable and typically 0. .l5 mag in EB-v. Hfl is generally weaker than predicted by LTE model atmospheres in the medium-temperature supergiants but is in reasonable agreement with the non-LTE calculations of Mihalas and Auer in the hottest, non-emission-line stars. Evidence is presented supporting the effective temperatures for the hotter stars which are indicated by the models. Subject headings:atmospheres, stellar - luminous stars Magellanic Clouds - Of-type stars - stellar evolution