SIMBAD references

We present first results on quantitative infrared spectroscopy of the brightest HeI emission line stars in the Galactic center. The observed HeI and H broad emission lines are caused by extremely strong stellar winds ({dot}(M)∼5 to 80x10^–5M_☉/yr) with relatively small outflow velocities (V_∞∼300 to 1000km/s). The effective temperatures of the objects range from 17,000K to 30,000K with corresponding stellar luminosities of 1 to 30x10⁵L_☉. Strongly enhanced helium abundances (N_He/N_H>.5) are found. These results indicate that the HeI emission line stars are evolved blue supergiants close to the evolutionary stage of Wolf-Rayet stars. They power the central parsec and belong to a young stellar cluster of massive stars which formed a few million years ago.