SIMBAD references

We report the first spectrally-resolved observations of the Be star γ Cas in the HeI λ6678 and Hβ emission lines using the Grand Interferometre a 2 Telescopes in the southern France. Milliarcsecond angular resolution measurements were carried in both lines and their neighbouring continuum during October and November 1993. The HeI λ6678 and Hβ maximum emissions correspond respectively to 1.05 and 1.5 of the local continuum level. The interferometric baselines ranged from 15m to 51m on the sky which correspond to angular resolutions of 9 to 3mas at HeI λ6678 and 6.5 to 2mas at Hβ wavelengths. We compare these values to predicted extents of Hβ and HeI λ6678 components of the circumstellar gas from models of radiative transfer in these lines. We conclude that the emitting region must be smaller than 8.5 stellar radius in Hβ and close to 2.3 stellar radius in HeI λ6678 which is, for HeI λ6678, smaller than the nearby continuum extent. These results confirm γ Cas basic parameters for this star obtained by Stee et al. on 1993 from their model constrained by GI2T observations in Hα line.