On the basis of homogeneous spectral observations carried out during 1978 - 1983 a two-dimensional quantitative spectral classification of the Fuors V1057 Cyg and FU Ori in the blue region was obtained. During three seasons (summer 1978, summer 1979 and summer-autumn 1981) the spectral class of V1057 Cyg changed from G2 to G5. In the period 1978 - 1981 the spectral class of FU Ori changed from F9 to G3. But during 1981 - 1983 no changes were observed. It is noted that the changes of spectral class do not correlate with the changes of the star's brightness. A difference between spectral and photometric definitions of the absolute magnitude of V1057 Cyg has been found. During the observations no changes of the luminosity class of V1057 Cyg and FU Ori were observed.
Flare Stars and Related Objects
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