International Gemini Observatory/NOIRLab/NSF/AURA
NIFS K-band spectrum of W51d/IRS2W zooming on the NIII multiplet emission and He II absorption
NIFS K-band spectrum of W51d/IRS2W zooming on the NIII multiplet emission and He II absorption, indicative of a very young massive star with spectral type as early as O3-4.
