|
:4<sup>1</sup>H → <sup>4</sup>He + 2e<sup>+</sup> + 2γ + 2ν<sub>e</sub> (26.7 MeV)
wherebu yerda e<sup>+</sup> is a— [[positronpozitron]], γ is a— gamma raynurlanish photonfotoni, ν<sub>e</sub> is a— [[neutrinoneytrino]], and H andva He are— isotopesmos ofravishda hydrogenvodorod andva helium,geliy respectivelyizotoplari. TheBu energyreaksiya releasednatijasida bymillionlab thiselektron reactionvolt isenergiya inchiqadi millions(eV ofjuda electronkichik voltsenergiya miqdori, whichshuning isuchun actuallybu onlyenergiya akatta tiny amount of energyemas). HoweverBiroq enormousbir numbersvaqtda of these reactions occur constantly,bunday producingreaksiyalarning alljuda theulkan energymiqdori necessarysodir toboʻlgani sustainuchun theyulduz star'snurlanishi radiationkuchli outputboʻladi.
{| class="wikitable" style="float: left;"
|+ Sintez uchun kerakli minimal massa
|+ Minimum stellar mass required for fusion
|-
!Unsur
!Element
![[SolarQuyosh massmassasi|SolarQuyosh<br />massesmassasi]]
|-
| HydrogenVodorod ||style="text-align: center;"| 0.,01
|-
| HeliumGeliy ||style="text-align: center;"| 0.,4
|-
| CarbonUglerod ||style="text-align: center;"| 5<ref>{{cite journal
| last1=Girardi | first1=L. | last2=Bressan | first2=A. | last3=Bertelli | first3=G. | last4=Chiosi | first4=C. | title=Evolutionary tracks and isochrones for low- and intermediate-mass stars: From 0.15 to 7 M<sub>sun</sub>, and from Z=0.0004 to 0.03
| journal=Astronomy and Astrophysics Supplement
| Neon ||style="text-align: center;"| 8
|}
InMassivroq moreyulduzlarda massive stars, helium is produced in a cycle of reactionsgeliy [[catalystkataliz|catalyzedkatalizatori]] byuglerod carbon—theboʻlgan [[CNO cycle-sikl|carbonuglerod-nitrogenazot-oxygenkislorod cyclesiklida]] ajralib chiqadi.<ref name="synthesis" />
In evolved stars with cores at 100 million kelvin and masses between 0.5 and 10 solar masses, helium can be transformed into carbon in the [[triple-alpha process]] that uses the intermediate element [[beryllium]]:<ref name="synthesis" />
| 