Complex sentence: Meissa is a blue spectral type O giant star and is the dominant member of a 5 million year old star-forming region known as the λ-Orionis cluster, or Collinder 69.
Split into simpler sentences: Meissa is a blue spectral type O giant star. This star is the dominant member of a 5 million year old star-forming region known as the λ-Orionis cluster, or Collinder 69.