How Exactly Does a Supernova Turn Into a Nebula?

A supernova is an event that occurs when a star has ejected enough matter into space to make the star collapse. This creates a massive explosion that can outshine an entire galaxy. However, most people don't know that this is usually where a supernova turns into the nebula it turned into. A nebula is made up of gas and dust in a rotating pattern around a central point, such as when planets are formed from debris orbiting around the sun.

The core explosion stage of a supernova produces a shock wave, which travels outward at speeds of about and reaches temperatures over. This form of energy is therefore not visible to the naked eye. After the shock wave passes quickly, the expanding explosion zone (E') is formed. The central shock wave leaves behind an expanding shell of material and plasma. This material is observed as the "nebula" of the supernova, composed of two parts. The first part is the hot ejecta, which reaches temperatures of over. The second part is the surrounding cold ejecta, which reaches temperatures of about. This, in turn, forms a second expanding shock wave, known as the shocked wind.

The shock wave from a supernova has at least one effect on the inner layer of its expanding atmosphere: it pushes gas inward with a force that can be as great as one-thousandth that exerted by the central explosion. This plasma "wind" can reach over —more than 20 times the speed of sound in air. The primary explosion's shock wave is not the only force that can move the gaseous material left by a supernova explosion. The central explosion also leaves behind the Crab Nebula, which is still detectable today. This nebula is large enough to be seen from Earth to cover an angular diameter. It also has a temperature of about.

During the formation of a nebula, a shell of material is created. This shell orbits the central region of the original star about per year. As time goes on, this material will cool in space between galaxies and eventually form a disk. It can also be assumed that some of the ejected material is sent back into space after a collision with another star. Most of the nebula's hydrogen comes from the explosion. Hydrogen is a particularly abundant element in supernovas, as it is a highly dense form of matter. So when a star explodes in a supernova, its outer layers are blasted away, and most of its hydrogen ends up as gas being ejected into space and interstellar space. About per cent of the total mass of the star is also made up of helium, but that is so light and fragile that it does not contribute much to a supernova explosion.

The supernova's shock wave affects the nebula: it can accelerate particles and gas in an area away from the explosion. This acceleration can cause these particles to move at very high speeds. These particles are called cosmic rays because they travel through space at nearly the speed of light. A shock wave from a supernova reaches a maximum temperature of about 50 million kelvins or over. Though this is a scorching temperature, it is not hot enough to destroy the hydrogen particles that make up most of the nebula. The shock wave can heat the gases around it up to temperatures. However, this is still not enough heat to destroy most of the nebula's gas particles.

A supernova emits large amounts of high energy gamma radiation. Surrounding molecules then absorb the gamma rays. When the molecule absorbs all the gamma rays, it makes a neutron, absorbing another neutron. This process continues until one of these neutrons falls into the star's centre. There will only be one chance of this occurring when all the other neutrons have already been absorbed, so that means there will be no more atoms to absorb them. This is where the star will collapse and explode in a supernova. The matter that was once a star is now released into space. Which can range from large to small depending on how many neutrons were trapped in the centre of the star. These particles are now being blown into space by the sun and will transform into new stars and planets.

A supernova is a highly violent event that releases large amounts of energy and matter into space. The process of turning into a nebula is much less damaging. The matter is no longer the same as the original star, changing. It has turned into a gas or perhaps dust, which expands and grows in size until it becomes a nebula. This process can take centuries or even thousands of years, depending on the central point's distance from Earth and its size when it exploded. This is why a supernova turns into a nebula, but not the other way around.