The final event that marks the birth of a star is bipolar flow. This is an eruption that releases two massive jets of gas that clear away gas and dust from the star’s surface.Know More
However, a gravity disturbance within a nebula, a cloud of interstellar dust and gas, is the event that initially begins the entire process. The disturbance might be caused by a comet, a shockwave from a distant explosion or some other event.
The force from the disturbance causes particles to collide and form clumps. As the clumps grow in mass and gravitational pull, they draw even more surrounding particles inward, which begin to rotate and flatten, forming a rotating disc.
As the speed of rotation increases, the disc pulls more material inward, creating a hot, dense core called a protostar. The process of drawing in gas and growing hotter continues until the protostar’s temperature is high enough to trigger the sustained nuclear fusion of its hydrogen atoms.
Though fusion produces an outflow of energy, material continues to flow inward until sufficient mass collapses to cause the bipolar flow. The young star then stabilizes and becomes a main sequence star whose outward pressure from hydrogen fusion is balanced with the inward pull of gravity.Learn more about Stellar Astronomy
A neutron star is a star whose core is made up mostly of neutrons. They are what's left of stars that were four to eight times more massive than the sun. These stars originate from catastrophic explosions called supernovae.Full Answer >
A circumpolar star is so close to one of Earth's two poles that instead of rising and setting like other stars, it seems only to revolve around one point in the sky. This effect is caused by Earth's rotation on its axis and can be seen at high latitudes.Full Answer >
There are multiple possible outcomes when a star dies, depending on how large the star was. Smaller stars may form white dwarfs or neutron stars, while more massive stars usually explode in a supernova, which can result in either the creation of a neutron star or black hole.Full Answer >
The gases that surround a star or planet — called the object’s atmosphere — vary from one celestial object to the next. Many planets have complex atmospheres, but stars usually have simple ones. As with the Earth’s sun, the atmospheres of most stars are composed of hydrogen and helium. However, a few neutron stars with oxygen-rich atmospheres have been documented.Full Answer >