Browsing: Protostar

Protostars are the earliest stage in the stellar formation process, representing the phase when a collapsing cloud of gas and dust begins to form a star. This phase occurs within molecular clouds, often visible as dark nebulae, where regions of higher density start to contract under gravity, initiating the core’s formation. As the core contracts, it heats up, primarily due to gravitational energy being converted into thermal energy, eventually becoming hot enough for nuclear fusion to begin. Protostars are enveloped in a cocoon of dust and gas, making them invisible in optical wavelengths but detectable in infrared and submillimeter ranges. They often exhibit outflows and jets, which help in shedding angular momentum, allowing more material to fall into the forming star. The protostellar phase continues until the star has accreted enough mass to initiate stable hydrogen fusion in its core, transitioning into a main-sequence star. This developmental stage is crucial for understanding the birth and early evolution of stars.