What Makes A White Dwarf?

Cassiopeia A Supernova – A Supernova is a star that has exploded and increases in brightness because it’s mass is now ejected.

seen day and night in the sky. It is now known as the crab nebula, and is a breeding ground for smaller stars. Another way for a supernova to be created, is when a white dwarf siphons off hydrogen from another star to the point where it will become unstable and explode.

First, I will discuss protostars. A protostar is a very young star that is gathering gas from a giant molecular cloud. “The protostar phase of stellar evolution lasts about 100,000 years”. (www.universetoday.com) As time goes on, pressure and gravity increase, which therefore forces tho protostar to collapse down. The energy released by the

A nebula collapses due to gravitational or magnetic disturbance. Potential energy is lost when gases collect, this causes an increase in temperature. The more it collapses the more the temperature will increase. Many stars will form due to the collapsing of a cloud that separates into many smaller clouds each of which becomes a star. The part to collapse faster than any other part is the core while the outer parts collapse at a slower rate, to conserve angular momentum the cloud begins to rotate faster and faster, the outer parts collapse slower than the core. The molecules of hydrogen gas break into hydrogen atoms when the core reaches a temperature of 2000 degrees kelvin (1726.85 degrees Celsius). It begins to look like a star when fusion reaction begins when the core reaches a temperature of 10000 degrees kelvin (9726.85 degrees

When this happens several things can happen depending on the size and mass of the star. Take our Sun for example, when it grows old it will enlarge into a Red Giant, then it will shrink into a White Dwarf. This is one of the more “Peaceful” options. (It will engulf Mercury and Mars when it is a Red Giant and make life on Earth very hot.) However if the star has a very large mass, at least 1.4 times the mass of our sun, it will explode in a supernova casting away most of the star's mass. Leaving only the core, the core will begin to collapse, only this time it can’t explode with no fuel left. So it shrinks to a tiny size but it retains its same mass and is extremely dense. Edward Rayne says “[after] the star's collapse it will continue to shrink until the matter is all compressed into an infinitely small, infinitely dense point called a singularity. This is the centre of a black hole.” This is when the black hole forms.

You are probably wondering where did these things come from and how are they formed? Well I am about to tell you, Low mass stars are formed when all the helium has fused into carbon, then the core collapses. As the star collapses, the outer layers of the star are expelled. A planetary nebula is formed by the outer layers a massive star that will undergo a supernova explosion. Then when the low mass star is done forming after billions of years they start to become giants.

In most cases a star will move into the planetary nebula phase, as an expanding, glowing shell of hot gas also known as plasma. This happens from a low-mass star in the end of their red giant phase, becoming unstable. The exterior layer drifts away from it’s core, which is now consider a white dwarf star, due to stellar winds. If the dying star have a mass of over 8 suns, it will become a supernova. Just like a planetary nebula, the cause of it is when a star runs out of nuclear fuel. From the massive star’s lack of outward pressure to balance its inward gravity, the star collapses into the core expelling a nuclear explosion. Also like the nebula, gas and dusts are scattered around space that will be used for the birth of future stars. At this point, the former supergiant is either a neutron star or a black

Like our sun, it will eventually run out of hydrogen and helium fuel at the star’s core. However, it will have enough mass and pressure to fuse carbon (S2). Next, over time, heavier elements build up at the center and it becomes layered like an onion (S2). The elements will become lighter and move towards the outside of the star. The core will heat up and become dense. The core will become extremely heavy; so heavy that its gravitational force will not be able withstand it; causing it to explode. The explosion spews out stellar material throughout space

7. What is a planetary nebula, and how does it form? A planetary nebula is a luminous shell of gas that comes out of an old star with a low mass (G-9). When enough of the gas leaves a star for the core to become visible, the expanding dust and gases form a planetary nebula (408). 12. What is the mass range of neutron stars? The range of neutron stars is millisecond pulsars. Millisecond pulsars is the name of companions pulsars which connect the mass of a star but not necessarily a neutron star. The extra weight after the connection allows the star to gain a faster speed while falling (434 — 9th edition).

White dwarf formed, particularly when there is availability of multiple stars; from this multiple star, it can experience similar exciting end as a nova. The gravity of this star may drag the hydrogen from the external layer of star onto itself because of the closeness with the other.

The inner core has reached its final high density state and the nuclear burning surrounding it increases in intensity. The helium burning becomes unstable and the shell becomes sensitive to changes in temperature and high in pressure, causing explosive flashes. The star’s outermost layers begin to expand and contract as they heat and cool in response to the flashes. Once the star exhausts the remaining fuel at its core, ultraviolet radiation ionizes the surrounding cloud and the star. The result is a planetary nebula, which is a round or oval shape created by the escaping of expanding

The Milky Way contains billions of stars with different ages and sizes. One example of a star which is closest to earth is the Sun. Just like all the other stars the sun is a luminous ball of gas which mostly contains hydrogen and helium and is held together with its own gravity. All the stars produce their own energy by a process called nuclear fusion. Stars life begins in the place what astronomers call the Nebulae. A nebula is enormous cloud consisting of dust and gas; mainly hydrogen and helium. There are three different types of nebulae. The first one is Emission Nebula. Emission Nebulae are usually red and pink in colour because they are filled with hydrogen gas. The Emission Nebula is very hot because of the newborn stars zap there surrounding

There are at least two different size ranges for black holes. The first are those of stellar mass, about 10 to 24 times as massive as our sun (“Black Holes”). The second are supermassive black holes (“Black Holes”). Supermassive black holes can contain millions to billions of times the mass of our sun (“Black Holes”). They can grow to such enormous sizes because of the considerable amounts of matter in the center of galaxies, where supermassive black holes are found (“Black Hole Images, Facts and Information”). For

White dwarfs are the remnants of stars similar to the Sun after the exhaustion of nuclear fuel. When the nuclear burning nears exhaustion, the star expels majority of its outer layers, creating a planetary nebula. The remaining core could have temperatures of more than 100,000K. Some white dwarfs gather matter from nearby stars via accretion while most others cool down over a timespan of billions of years. Soft X-ray as well as extreme UV observations are a key tools in determining the composition of these stars. [1]

Main sequence stars like our own sun enduring in a state of nuclear fusion during which they will produce energy for billions of years by replacing hydrogen to helium. Stars change over billions of years. When their main sequence phase ends they pass through other states of existence according to their size and other characteristics. The larger a star's mass, the shorter its lifespan is. As stars move toward the end of their lives, much of their hydrogen will be converted to helium. Helium sinks to the star's core and raises the star's temperature—causing its outer shell to expand. These large, puffy stars are known as Red Giants. The red giant phase is actually a prelude to a star shedding its outer layers and becoming a small, dense body called a White Dwarf. White dwarfs cool down for billions and billions of years, until they finally go dark and produce no energy at all. Once this happens, scientists have yet to observe, such stars become known as Black Dwarfs. A few stars avoid this evolutionary path and instead go out with a bang, exploding as Supernovae. These violent explosions leave behind a small core that will then turn into something called a Neutron Star or even, if the remainder is large enough, it is then turned into something called a Black Hole.