3 ms·

Why?

• Keyframe 2y ago
  probably because it depends on the star types that produce oxygen; it takes awhile until these stars form from previous in sequence. https://science.nasa.gov/universe/stars/types/#neutron-stars https://science.nasa.gov/universe/stars/types/#neutron-stars
• interludead 2y ago
  Because oxygen is formed in stars and then dispersed when they die (like in supernovae), so finding it in such a young galaxy means that at least one generation of massive stars had already formed and died