Primaärien

Primaärien is a term used in astronomy to describe the initial stage of star formation. This phase begins within giant molecular clouds, vast regions of interstellar gas and dust. Gravitational forces cause denser clumps within these clouds to collapse. As a clump collapses, it begins to spin faster due to conservation of angular momentum, and it heats up due to the conversion of gravitational potential energy into thermal energy. This collapsing, spinning, and heating core is considered a proto-star.

During the primaär phase, the proto-star is still embedded within its surrounding envelope of gas and dust, making it difficult to observe directly in visible light. However, it can be detected in infrared wavelengths. The proto-star accretes more material from the envelope, increasing its mass and temperature. Eventually, the core becomes hot and dense enough for nuclear fusion to begin, marking the transition from the proto-stellar phase to the main sequence stage of a star's life. The timescale for the primaär phase varies greatly depending on the mass of the star being formed, ranging from tens of thousands of years for massive stars to millions of years for sun-like stars.