MWC 314 = BD was discovered by Merrill (1927), who found hydrogen and FeII emissions in its spectrum. Swensson (1942) detected the interstellar H and K CaII lines and 4430 Å band, Balmer emissions from H to H8, emissions of NaI at 5890 and 5896 Å, and, finally, numerous emissions of metallic lines including Fe II, Cr II, [Fe II], and two lines of [Fe III]. Photospheric lines and spectral features of late-type stars were not observed in these, rather low-resolution, spectra. The first photoelectric UBV photometry obtained by Hiltner (1956) showed that the star was extremely red (), but with it is located at the reddening line for early-B stars. Near-IR photometry obtained by Allen (1973) implies a small excess radiation in this region. Recently Miroshnichenko (1996) reported results of a new photometric and spectroscopic study of MWC 314. It was based on nearly 50 photometric UBVRI and UBVRIJHK observations obtained in 1990-1994, two medium-resolution spectra (4000-7500 Å, dispersion 50 Åmm-1, resolution 2 Å) obtained at the 6-meter telescope of the Russian Academy of Sciences in 1989 and 1991, the IUE low-resolution spectra obtained in 1984 and 1992, and the IRAS photometry at 12 and 25 m. He found that the object is variable in all photometric bands with a mean amplitude of . Analysing the spectral energy distribution (SED) and Balmer emission line profiles he concluded that MWC 314 is a highly reddened supergiant with and the following main parameters: , = 30000 K, . The strong and rather narrow Balmer lines indicate that the star have a high mass loss rate: M = 310yr-1. The wind terminal velocity, = 500 km s-1, is much lower than in normal supergiants. All these findings led Miroshnichenko to the suggestion that MWC 314 is a candidate LBV, the second one in the northern hemisphere after P Cyg.
MWC 314 is not an ordinary supergiant. It displays very strong Fe II emission lines which are also significant features of the spectra of B[e] stars (e.g., Andrillat et al. 1996). However, it has not been previously recognized as a B[e] star because very few forbidden lines have been so far identified in its spectrum and furthermore there is no evidence of circumstellar dust as its IR-excess is very small.
Miroshnichenko (1996) noted that some problems remained with this object. In particular, high-resolution spectroscopy was needed to obtain more detailed emission line profiles and to detect eventual photospheric lines. The stellar temperature estimate was based mainly on the SED in the UV region since Balmer line profiles were not very sensitive to the temperature changes. Moreover, He II lines have not been detected in the previous spectra indicating that < (26-27) 103 K (Schmutz et al. 1991).
Recently, a series of papers reporting results of high-resolution spectroscopic observations of strong emission-line B[e] stars has been published (Jaschek et al. 1996a,b; Andrillat et al. 1996, 1997). The present paper is aimed to make further progress in the understanding of a similar object. Here we report the results of a new, more high-dispersion, spectroscopy of MWC 314 and its analysis.
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