The stellar content of obscured Galactic giant H II regions. I. W43

Near-infrared images of the Galactic giant H II region W43 reveal a dense s tellar cluster at its center. Broadband JHK photometry of the young cluster and K-band spectra of three of its bright stars are presented. The 2 mu m spectrum of the brightest star in the cluster is very well matched to the s pectra of Wolf-Rayet stars of subtype WN7. Two other stars are identified a s O-type giants or supergiants by their N III and C IV emission. The close spatial clustering of O- and the hydrogen WN-type stars is analogous to the intense starburst clusters R136 in the Large Magellanic Cloud and NGC 3603 in the Galaxy.