The Story of our Sun Flashcards
Radius
7 × 10^8 m 109 Earth radii
Radius
7 × 10^8 m 109 Earth radii
Mass
2 × 10^30 kg (330,000 Earth masses)
Density
Density 1.4 × 10^3 kg/m3 (1.4 times water)
Distance
Distance 150 × 10^6 km ( Defined as 1 A.U.)
Surface Temp
5780 K
Core Temp
15,000,000 K
Composition
71% hydrogen, 27% helium, 2% heavy elements
Power output
3.9 × 10^26 J/s
Age
4.5 billion years
Expected lifetime
12-15 billion years
The Sun age,
our nearest star, is estimated to be about 4.6 billion years old. This age is determined through various methods, including radiometric dating of meteorites and the study of the Sun
Structure and hydrostatic
equilibrium
the structure of a star is maintained by the equilibrium between gravity and the pressure generated by nuclear fusion reactions. This balance is crucial for stabilizing the star and allowing it to shine steadily over long periods of time.
Nuclear Fusion
is a process in which atomic nuclei combine to form a heavier nucleus, releasing a tremendous amount of energy in the process.
Future evolution
Main Sequence: -> Red Giant -> Helium Flash -> AGB
Red giants and planetary
nebulae
As a red giant star nears the end of its evolution, it undergoes a dramatic transformation into a planetary nebula.
Mass Loss: Ionized Gas: Complex Structures core becomes white dwarf
AGB nucleosynthesis
refers to the process by which certain elements are synthesized in the advanced stages of stellar evolution on the Asymptotic Giant Branch (AGB). AGB stars are evolved, low- to intermediate-mass stars that have exhausted the hydrogen fuel in their cores and have expanded to become red giants
