  We present $K$-band spectra of the near infrared counterparts to IRS2E and
IRS2W which is associated with the ultracompact HII region W51d, both of them
embedded sources in the Galactic compact HII region W51 IRS2. The high spatial
resolution observations were obtained with the laser guide star facility and
Near infrared Integral Field Spectrograph (NIFS) mounted at the Gemini North
observatory. The spectrum of the ionizing source of W51d shows the photospheric
features NIII (21155 \AA) in emission and HeII (21897 \AA) in absorption which
lead us to classify it as an young O3 type star. We detected CO overtone in
emission at 23000 \AA in the spectrum of IRS2E, suggesting that it is a massive
young object still surrounded by an accretion disc, probably transitioning from
the hot core phase to an ultracompact HII region.

Astrophysics