supergiant
When a main sequence star exhausts its hydrogen fuel in the core, it begins to evolve into a red giant. As hydrogen fusion ceases in the core, the core contracts and heats up, while the outer layers expand and cool, giving the star a red appearance. Eventually, the core may start fusing helium into heavier elements, leading to further evolutionary stages depending on the star's mass.
A star is a giant ball of hot gases that undergo nuclear fusion in its core. The intense pressure and temperature at the core of a star cause hydrogen atoms to fuse together to form helium, releasing a tremendous amount of energy in the process.
As a planetary nebula, a star can shed some of its outer gases without losing them all and the cycle can be repeated many times. As a nova, the star will blow out its outermost layers and eventually leave the core, which becomes a white dwarf star. As a supernova, a large star blows off all of its gases, leaving behind a pulsar or a black hole.
A star that begins as a large cloud of dust and gas is called a protostar. It forms as gravity causes the dust and gas to clump together and initiate the process of nuclear fusion in its core.
If there is no hydrogen left at the core of star then hydrogen fusion cannot occur. What happens in the core of a star before that happens is that helium begins to fuse, and then the other elements going up the periodic table until carbon. And then if the star explodes into a supernova, traces of the higher elements are fused as well.
A star is a huge celestial body composed mainly of hydrogen and helium gases undergoing nuclear fusion in its core that produces light and heat through the release of energy.
As the gases in a protostar begin to collapse, the central core begins to heat up due to pressure. As more gases are absorbed, the greater the pressure. Once the temperature of the core reaches 10 million degrees K, hydrogen fusion begins, and the star begins it's life on the main sequence. The star will stay on the main sequence whilst it still has hydrogen to fuse. Once all the hydrogen has been used, the star will drop out of the main sequence. Protostar stage in the stellar evolution. [See related question]
A star becomes a star - "is born" - when the process of nuclear fusion begins in the core of the star.
red giant
STARS
red giant
A star is considered born when nuclear fusion begins in its core, creating energy and light. This process marks the transition from a protostar to a true star.
When a main sequence star exhausts its hydrogen fuel in the core, it begins to evolve into a red giant. As hydrogen fusion ceases in the core, the core contracts and heats up, while the outer layers expand and cool, giving the star a red appearance. Eventually, the core may start fusing helium into heavier elements, leading to further evolutionary stages depending on the star's mass.
A star is a giant ball of hot gases that undergo nuclear fusion in its core. The intense pressure and temperature at the core of a star cause hydrogen atoms to fuse together to form helium, releasing a tremendous amount of energy in the process.
A huge ball of superheated gases is called a star. Stars are primarily composed of hydrogen and helium and generate energy through nuclear fusion in their cores, which produces light and heat. The Sun is the closest example of a star to Earth.
A core of rock and ice that attracts gases is likely referring to a comet. Comets are celestial objects composed of rock, dust, ice, and frozen gases that orbit the Sun. When a comet's orbit brings it close to the Sun, the heat causes the ice to vaporize, releasing gases and creating a glowing coma and tail.
A star is primarily made up of hydrogen and helium gases. These gases undergo nuclear fusion in the star's core, creating intense heat and light. Other elements such as carbon, oxygen, and iron are also present in smaller amounts.