The Chemical Composition of IOTA Herculis

The chemical composition of the sharp-lined B3 V star Her has been determined by a mode 1-at- mosphere technique. All elements considered in this analysis seem to have solar-type abundances. The effective temperature determined for this star by the criterion of ionization balance is dependent upon whether blanketed or unblanketed model atmospheres are utilized. The former indicate an effective temperature of 17000 K, whereas the latter indicate 20000 K. Reliable scanner data, available measurements of ultraviolet flux and the work of Hanbury Brown et al. favor the lower temperature. The effective temperature of a B3 V star as determined by Hanbury Brown et a'. is closer to 17000 K. The logarithm of the surface gravity is near 4.0.