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What happens to the temperature and pressure in a protostar as it collapses?

What happens to the temperature and pressure in a protostar as it collapses?

As the center of the protostar is compressed, it heats up. Thus, during the initial stages of the protostar’s collapse, its surface temperature T is constant, while its radius R decreases; as a consequence, the luminosity L decreases. Eventually, the heat from the center of the protostar makes its way to the surface.

When a protostar contracts or collapses what happens to it?

An object can be considered a protostar as long as material is still falling inward. After about 100,000 years or so, the protostar stops growing and the disk of material surrounding it is destroyed by radiation. It then becomes a T Tauri star, and is visible to Earth-based telescopes.

How does a protostar collapse?

Stars begin to form from clouds of gas in space. The cold temperatures and high densities (compared to elsewhere in space, but would be considered a vacuum on Earth) of these clouds allow gravity to overcome thermal pressure and start the gravitational collapse that will form a star.

Why do protostars shrink?

The higher-mass protostars get much hotter as they contract, than they get dense. That is, as a protostar moves to the left in the HR Diagram, its outer convective zone shrinks toward the surface, and may even disappear.

What happens when a protostar joins the main sequence?

When the protostar starts fusing hydrogen, it enters the “main sequence” phase of its life. Stars on the main sequence are those that are fusing hydrogen into helium in their cores. The radiation and heat from this reaction keep the force of gravity from collapsing the star during this phase of the star’s life.

Why does a collapsing protostar tend to rotate and flatten?

HEATING: The temperature of the solar nebula increases as it collapses. As the cloud shrinks, its gravitational potential energy is converted to the kinetic energy of individual gas particles falling inward. This flattening is a natural consequence of collisions between particles in a spinning cloud.

What happens when a protostar contracts?

As the central temperature reaches ~107 K, hydrogen fusion begins in the core of the protostar. The protostar continues to contract and heat up until the fusion rate balances the energy radiated away. When this balance is struck, contraction stops and the star settles onto the main sequence.

Do protostars expand?

The heat from this fusion reaction tends to inflate the protostar, and thereby helps determine the size of the youngest observed pre-main-sequence stars.

How does a nebula collapse?

Nebulae are made of dust and gases—mostly hydrogen and helium. The dust and gases in a nebula are very spread out, but gravity can slowly begin to pull together clumps of dust and gas. Eventually, the clump of dust and gas gets so big that it collapses from its own gravity.

What elements are in a protostar?

Early protostars would have been formed from the gasses that were created soon after the big bang. They would be 75% Hydrogen, 25% Helium with traces of Lithium.

What would happen to a protostar that formed without any rotation at all?

What would happen to a protostar that formed without any rotation at all? – It would not have planets. Is contraction necessary during nuclear fusion for a newborn star? – Yes, contraction must continue until the core becomes hot enough for nuclear fusion.

Why does a collapsing protostar tend to get hot?

A collapsing cloud will tend to heat up, due to the conversion of gravitational potential energy into thermal (kinetic) energy. When a gas heats up, its pressure increases and starts to slow down the contraction. The core becomes opague and hydrostatical balance settles. The protostar is born.