The LMC emission line star S 22 (=HD 34664). III. Ultraviolet to infrared energy distribution.

Abstract

New observations of the superluminous star S22 in the Large Magellanic Cloud obtained with the ultraviolet satellite IUE and in the infrared are discussed. The low resolution ultraviolet spectrum is dominated by Fe II emission and absorption lines, probably formed in an expanding cool circumstellar envelope. An attempt was made to synthesize the UV spectral features with theoretical computations of the Fe II line emission and absorption. The continuum energy distribution, corrected for an interstellar extinction of E(B-V) = 0.17, can be fitted with a power law F(lambda) approximately 1/(lambda-squared), from 0.2 to 1.5 microns, which could be explained by an accretion disk model. Other implications and suggestions for future investigations are discussed.