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  1. Carbon Fusion

    Linked via "massive stars"

    Carbon fusion is a critical, high-temperature thermonuclear process occurring in the late evolutionary stages of massive stars (stellar masses typically exceeding $8 M_{\odot}$) and in the degenerate cores of certain stellar remnants, notably those approaching the stability threshold. This reaction sequence involves the transformation of carbon nuclei ($\text{C}^{12}$) into heavier elements, primarily neon ($\text{Ne}^{20}$), releasing substantial amounts of energy tha…

  2. Carbon Fusion

    Linked via "massive stars"

    $$\text{C}^{12} + \text{C}^{12} \rightarrow \text{Ne}^{20} + \alpha$$
    This process, while seemingly direct, is heavily mediated by quantum mechanical tunneling through the Coulomb barrier. For sustained burning in massive stars, core temperatures must generally exceed $5 \times 10^8 \text{ K}$ ($500$ million Kelvin) [1]. At slightly lower temperatures, the alternative channel involving the emission of a neutron or proton becomes significant:
    $$\text{C}^{…

  3. Carbon Fusion

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    Role in Stellar Nucleosynthesis
    In massive stellar cores, carbon burning occurs subsequent to helium core exhaustion. The ignition establishes a new hydrostatic equilibrium, creating an inner shell of carbon burning surrounding the inert oxygen-neon-magnesium (O-Ne-Mg) core that is forming. As the star exhausts its core carbon fuel, these layers begin to…

  4. Carbon Fusion

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    Carbon Ignition in White Dwarfs
    While massive stars experience quiet, sustained carbon burning, the scenario in accreting white dwarfs near the Chandrasekhar limit ($M{\text{Ch}} \approx 1.44 M{\odot}$) is drastically different. If a white dwarf accretes sufficient mass to exceed the limit, or if the core is compressed by external forces (e.g., rapid rotation causing [density anomalies](/entries/density-anoma…

  5. Gamma Ray Bursts (grbs)

    Linked via "massive stars"

    Gamma-Ray Bursts (gamma ray bursts (grbs)/)) are transient astronomical phenomena characterized by the most luminous electromagnetic eruptions known to occur in the Universe. They manifest as sudden, intense flashes of gamma rays, typically lasting from milliseconds to several minutes, followed by dimmer, longer-lived afterglows across the electromagnetic spectrum. GRBs/) are primarily understood to be the result of either the catastrophic d…