Giant and highly luminous red Self-luminous object held together by its own self-gravity. Often refers to those objects which generate energy from nuclear reactions occurring at their cores, but may also be applied to stellar remnants such as neutron stars. in the later stages of Changes in a stars luminosity and temperature over its lifetime; conventionally, plotted on an Hertzsprung-Russell (HR) diagram. All stars, irrespective of their mass spend most of their lifetime on the main sequence. The more massive a star, the more luminous and hotter it is. As all stars age, they enter after it has left the main sequence. These red stars have a relatively cool surface whose In the context of planetary formation, the core is the central region of a large differentiated asteroid, planet or moon and made up of denser materials than the surrounding mantle and crust. For example, the cores of the Earth, the terrestrial planets and differentiated asteroids are rich in metallic iron-nickel. has burned most of its Lightest and most common element in the universe (~92% by atoms; ~75% by mass). Hydrogen's isotopes are: • 1H (99.9885 %)
• 2H (0.0115 %), also called deuterium.
• 3H, also called Tritium, is a radioactive (t½ = 12.32 y) by-product of atmospheric thermonuclear tests in Earth's hydrosphere and atmosphere.
. Red giants lose parts of their atmospheres and thus provide new elements into interstellar space such as Element commonly found in meteorites, it occurs in several structural forms (polymorphs). All polymorphs are shown to the left with * indicating that it been found in meteorites and impact structures: a. diamond*; b. graphite*; c. lonsdalite*; d. buckminsterfullerene* (C60); e. C540; f. C70; g. amorphous carbon; h. carbon nanotube*..These stars are found on the upper-right hand side of the Hertzsprung-Russell diagram (high Basic property used to characterize stars, luminosity is defined as the total energy radiated by a star each second. An object’s luminosity is often compared to that of the Sun (Lsun = 4 × 1033 ergs/s = 3.9 × 1026 Watts). Luminosity has the same units as power (energy per, temperature ~2000-3000 K, diameter 10-100 Rsun). The Our parent star. The structure of Sun's interior is the result of the hydrostatic equilibrium between gravity and the pressure of the gas. The interior consists of three shells: the core, radiative region, and convective region. Image source: http://eclipse99.nasa.gov/pages/SunActiv.html. The core is the hot, dense central region in which the will become a red giant in ~5 billion years.
Some or all content above used with permission from J. H. Wittke.