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Star formation is an incredible transformation of gas and dust into a brilliant star, like the ones we see in the night sky. The journey begins in a molecular cloud, which is a cold and dense section of the galaxy made up of gas and dust. These clouds are the perfect incubators for forming stars.
Gravity plays a vital role in star formation. Within a molecular cloud, tiny bits of matter start pulling on each other due to gravitational forces. This gentle pull slowly gathers the gas and dust together, leading to the formation of a dense core.
As this core draws in more material, it becomes more compact and starts to heat up. This phase marks the birth of a protosun, which is a precursor to a fully formed star. The process continues, transforming this rotating core into a hot, shining entity that will one day become a star.

• Stars begin in molecular clouds.
• Gravity pulls gas and dust together.
• A dense, hot core forms - the protosun.

Gravitational energy is a key player in the universe, particularly in the formation of stars like the protosun. As the protosun forms, gravity helps it to shine brightly. Here's how it works:
Gravity makes everything fall towards the center. So, when a protosun forms, gravity pulls the gas and dust inward, making the core denser and hotter. As the core gets squeezed, pressure builds up inside.
This increase in density and pressure causes a remarkable phenomenon: the emission of light and heat. This is because the particles in the core get compressed, transforming gravitational energy into thermal energy, which we observe as a shining protosun.

• Gravity compresses the core inward.
• Compression increases pressure and temperature.
• This process turns gravitational energy into light.

Nuclear fusion is the powerhouse behind every shining star, including what was once a protosun. During this process, small nuclei like hydrogen are fused to form larger cores such as helium. This fusion releases vast amounts of energy, enabling the star to shine for billions of years.
In the life of a protosun, nuclear fusion marks its transition into a main-sequence star. Once the core temperature reaches about 10 million Kelvin, fusion reactions start.
These conditions are crucial for the protosun to stabilize and continue shining. It's like a delicate balance where gravitational forces pushing inwards are countered by the energy output from fusion pushing outwards. This balance allows the star to achieve a long-lasting equilibrium.

• Fusion of hydrogen into helium occurs.
• Fusion releases significant energy.
• Achieved at core temperatures of 10 million Kelvin.