Figure 3: Relationship between Oxygen Abundance and Carbon-to-Oxygen Abundance Ratio (C/O) (IMAGE)
Caption
This diagram compares the oxygen abundance (horizontal axis) with the ratio of carbon to oxygen (vertical axis) in various astronomical objects. LAP1-B (red circle) is characterized by an exceptionally low oxygen content combined with a notably high carbon ratio. This chemical composition aligns remarkably well with theoretical predictions for the material dispersed by the explosions of the universe's first-generation stars (purple shaded region). This suggests that we may have captured the very moment when elements forged by the first stars were inherited by a galaxy for the first time. For comparison, the background grey symbols represent ancient stars in our Milky Way (crosses) and data from massive cosmic gas clouds known as Damped Lyman-alpha systems (DLAs) (diamonds). The area enclosed by the blue line represents the stellar distribution within present day’s UFDs, confirming that LAP1-B possesses a nearly identical chemical composition. LAP1-B offers the first example of these characteristics being confirmed in an active star-forming "galaxy" as far back as 13 billion years ago. In contrast, LAP1-B sits far outside the predicted range for "subsequent generations of enriched stars" (orange shaded region), highlighting its extraordinary nature.
Credit
© The Author(s), under exclusive licence to Springer Nature Limited 2026. Nakajima K. et al., Nature (2026).
Usage Restrictions
Reproduction permitted for press release use only. No further reuse or modification allowed.
License
Licensed content