Questions about the early phases of the star formation process. A protostar is a large mass of gas that results of the contraction of a molecular cloud.

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Why is the core of a gas giant supported by electron degeneracy pressure instead of nuclear fusion?

After a Sun-sized protostar forms, its core will become denser over time due to radiation. The core eventually gets dense and hot enough for hydrogen fusion to take place. In the late phases of the ...
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What decides the direction in which the accretion disk spins?

Planets lie on the same plane because of the accretion disk formed during the Protostar stage, as I read in this question. I also read about the collision of particles in the gas cloud causing the ...
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Is the conversion from proto-star to main sequence an event or a process?

When a proto-star becomes a main sequence star, is that something that happens in an instant when a certain threshold is met, or is it a process that takes a few thousand/million years?
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How do stars or galaxies get their spin?

It is my understanding that when a star, a planetary disk, or a galaxy forms, the rotational momentum of the whole system is conserved. Due to the smaller size of the resulting object, it will spin ...
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Accretion of in-falling material for a young main sequence star

I'm reading material that is seemingly contradictory. Some sources indicate that the evolution of a protostar to a main sequence star is characterised by a stellar wind that precludes the accretion ...
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Is there enough hydrogen left after a star dies so another star will have enough to light up?

A star consumes quite a lot of hydrogen in its life, and is pretty much "vacuuming" everything in its vicinity. After it dies (eventually by supernova which will spread all its composition over light ...
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1answer
74 views

How can pre-main sequence stars radiate more energy than main-sequence stars?

How can a pre-main sequence star radiate more energy by gravitational contraction than a main-sequence star can by hydrogen fusion?
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Source of T Tauri wind?

What particularly causes the T Tauri star to eject the strong bipolar wind which clears the gases around the star?
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Timescale of ignition of a protostar?

What is the timescale of start of nuclear fusion as T Tauri type star transforms into a Main Sequence star? Wikipedia article on T Tauri type stars mentions: Their central temperatures are too ...