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Jakub Skowronski
All curiosities

Curiosity☉ Sun

If 14N(p,γ)15O were twice as fast, this model of the Sun's centre would end up with twice as much oxygen‑15 (×2.0).

  • Biggest knock-on effect: 12C (×2.0).
  • CNO reactions only, about 1% of the Sun's power (a few per cent at its centre): energy output ×1.9.

Oxygen‑15 gives off CNO neutrinos as it decays; Borexino first detected them in 2020.

One-zone model at 16 MK over 1 billion years. Real stars adjust. The C, N and O start as fresh fuel at today's temperature and density, not as the Sun's processed core. The energy is that of this gas at the model's temperature, not the star's luminosity: a real star would adjust its temperature to keep its luminosity. Doubling is a what-if, not the rate's actual uncertainty. How well this rate is known: improving.

Try itHow we know this rate
Rate:
14N(p,γ)15O — G. Imbriani et al (2005), Eur. Phys. J. A 25, 455; REACLIB im05
Improving:
Recent measurements have narrowed the rate; some uncertainty remains.
Model:
one-zone model; JINA REACLIB reaclib_default2_20250330, pynucastro 3.1.0; 2026-10-13