THE TEMPERATURE OF THE SUPERGIANT ALPHA-PER

Because the bright supergiant alpha Per is located in cluster, and bec ause its angular diameter has been measured, its log g is known observ ationally, as is its atmospheric microturbulence. Using these observed parameters, we compare its energy distribution derived from IUE spect ra and B, V, R, I, J, and K with model atmospheres convolved with inst rumental sensitivity functions. The two most important advances in thi s study as compared with previous work are the use of well-calibrated ultraviolet fluxes and the use of models with an appropriate microturb ulence. Because the ultraviolet flux is sensitive to log g and microtu rbulence, as well as temperature, we fix log g at 1.5 and microturbule nce at 4 km s(-1), and derive the temperature from the best fit to the energy distribution (6270 K). Other recent temperature determinations are discussed, as are the sources of error. (C) 1996 American Astrono mical Society.