Gravity.
pickles
A nebula does not directly turn into a white dwarf. A nebula will collapse to form stars. Low to medium mass stars become white dwarfs after they die. Some are the result of a supernova and do not collapse, they merely dissipate over time. The Crab Nebula is the most prominent example of this.
"Primordial nebula" is a name used to describe a region of gas in space which is undergoing gravitational collapse, and which will eventually form a star.
The two main factors that cause a nebula to develop into a star are gravity and heat. Gravity pulls the gas and dust in the nebula together, causing it to collapse under its own gravity. As the collapse continues, the temperature and pressure in the core of the collapsing nebula increase, eventually reaching a point where nuclear fusion ignites, and a star is born.
Gravity.
pickles
A nebula does not directly turn into a white dwarf. A nebula will collapse to form stars. Low to medium mass stars become white dwarfs after they die. Some are the result of a supernova and do not collapse, they merely dissipate over time. The Crab Nebula is the most prominent example of this.
"Primordial nebula" is a name used to describe a region of gas in space which is undergoing gravitational collapse, and which will eventually form a star.
Gravitational collapse of a protostellar nebula.
helium and hydrogen gases
No. Stars are born when nebulae collapse, not when they expand.
The two main factors that cause a nebula to develop into a star are gravity and heat. Gravity pulls the gas and dust in the nebula together, causing it to collapse under its own gravity. As the collapse continues, the temperature and pressure in the core of the collapsing nebula increase, eventually reaching a point where nuclear fusion ignites, and a star is born.
Pressure and gravitymay have become unbalanced in thesolar nebula because of an externalforce such as a collision of the solarnebula with another nebula or from anearby exploding star. This type offorce, was strong enough to overcomethe pressure of the nebula and triggerits collapse.
Any star can form from a nebula. all it needs is some force to make it collapse, like a nearby supernova or gravitational pull.
List some events that can disturb the equilibrium of a nebula and cause it to being to
a nebula is the cloud of radioactive material dust smoke and debris caused by an exploding start, a nebula happens after a nova or super nova..and somtimes the collapse of a start causes black holes too in which case you wont see a nebula because the massive amount of gravity in the black holes sucks everything in, but yes a nebula is the cloud left over from an exploding star