Compression. Whenever anything is compressed, it heats up. In a proto-star, clouds of hydrogen gas are compressed by gravitational attraction, and the compression heats the gas.
The stage that comes after the nebula in the star's life cycle is the protostar stage. During this stage, gravity causes the gas and dust within the nebula to clump together and heat up, eventually forming a dense, hot core. This marks the beginning of nuclear fusion within the protostar.
Gravitational force - which pulls matter towards the center of the protostar and is responsible for its contraction. Thermal pressure - which is generated by the heat and pressure within the protostar's core and pushes outward to counteract the gravitational force.
the color of the protostar is red
Intense heat. If you are looking for the answer to a crossword puzzle it may just be "heat".
A protostar forms when gravity pulls the dust and gases in a nebula together.
A nebula is a vast cloud of gas and dust in space, while a protostar is a dense region within a nebula where gravity causes material to come together and heat up, eventually leading to the formation of a star. In essence, a protostar is a stage in the formation process of a star within a nebula.
A protostar is a star that is still forming and has not yet started a sustained fusion reaction. All the heat is the result of gasses being compressed. A white dwarf is the remnant of a dead star that has exhausted its fuel and is much smaller and denser than a protostar.
A protostar heats up internally as it contracts due to the gravitational potential energy being converted into thermal energy. The collapse of the gas cloud causes an increase in density and pressure, leading to a rise in temperature at the core. This process eventually triggers nuclear fusion and marks the start of a star's life cycle.
A protostar is not in energy balance because it is still in the process of accumulating mass and contracting under gravity. This causes the protostar to release energy as it heats up, but it has not yet reached a stable state of equilibrium where the energy being released is balanced by the energy being generated.
As gravity collapses the cloud to form a protostar, the temperature and luminosity both increase. The increase in temperature is due to the compression of material, causing the protostar to heat up as energy is released. The increase in luminosity is a result of the protostar radiating this energy.
Before a protostar can start glowing, it must finish collecting enough gas and dust to trigger nuclear fusion in its core. This process requires the protostar to reach a temperature and pressure high enough for hydrogen atoms to fuse together, releasing energy as light and heat.
A protostar is supported against gravitational collapse by the outward pressure generated from the heat produced by gravitational contraction. This pressure, known as radiation pressure, acts to counterbalance the force of gravity pulling the protostar inward. As the protostar continues to contract, it eventually reaches a point where nuclear fusion ignites in its core, providing an additional outward pressure that stabilizes the star against collapse.