Spectrophotometric observations of Lin 593

An analysis is reported of the low-resolution optical spectra of the very l ow excitation emission-line object Lin 593. It is demonstrated that this ob ject has a hot star that ionizes the surrounding nebula, thus creating a St romgren sphere. The hot star is the source of the observed continuum, while the Lines arise from the nebula ionized by the photons from the hot star. From the measurements of line emission and continuum, the chemical abundanc e and the physical parameters of the hot star as well as those of the ioniz ed nebula were obtained. It is shown that the chemical abundance of Lin 593 follows the SMC abundance as derived from previous analysis of similar obj ects, except for oxygen, which presents a low abundance compared to the SMC average abundance pattern. It is also shown that the hot star is a main-se quence star with spectral type in the range O9.5-B0.5 and, finally, that th e ionized nebula of Lin 593 forms a H II region for which several parameter s were obtained, characterizing it as a class III-IV, classical-dense, H II region.