SIMBAD references

An analysis is reported of the low-resolution optical spectra of the very low excitation emission-line object Lin 593. It is demonstrated that this object has a hot star that ionizes the surrounding nebula, thus creating a Strömgren 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 abundance and the physical parameters of the hot star as well as those of the ionized nebula were obtained. It is shown that the chemical abundance of Lin 593 follows the SMC abundance as derived from previous analysis of similar objects, 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-sequence star with spectral type in the range O9.5-B0.5 and, finally, that the ionized nebula of Lin 593 forms a H II region for which several parameters were obtained, characterizing it as a class III-IV, classical-dense, H II region.