A far UV investigation of luminous hot stars in the SMC cluster NGC 330.

Abstract

IUE observations of luminous blue stars in the SMC young cluster NGC 330 have been used to determine the reddening and the effective temperatures of the program objects. The reddening is estimated to be E(B - V) = 0.09 +/- 0.02, intermediate between old (~0.02) and recent (~0.12) evaluations. Stars with no recognized atmospheric anomaly show a good correlation between (B - V) and surface temperature, while stars identified as Be have temperatures higher than expected from their colours. The most luminous objects are consistent with an evolving mass of about 15 M_sun_; for the other ones an evolutionary interpretation appears difficult.