What are 6 stages of how a star forms?
Described below are the 6 stages of how a star of about one Solar Mass forms.
Stage 1 - Giant molecular cloud: A star begins life as a large cloud of gas. A region of high density within this cloud condenses into a huge globule of gas and dust and contracts under its own gravity.
Stage 2 - Protostar: A region of condensing matter begins to heat up and starts to glow forming protostars. This phase lasts about 10 million years.
Stage 3 - T Tauri stage: The young star begins to produce strong stellar winds, which pushes away the surrounding gas and molecules. This allows the forming star to become visible.
Stage 4 - Nuclear fusion: If the protostar contains enough matter the central temperature reaches 15 million degrees K. At this temperature, nuclear reactions in which hydrogen fuses to form helium can start.
Stages 5 & 6 - Main sequence star: The young star reaches hydrostatic equilibrium, in which its gravity compression is balanced by its outward pressure, giving it a solid shape. The star begins to release energy, stopping it from contracting even more and causing it to shine. The star spends 90 percent of its life in this Main sequence stage, fusing hydrogen to form helium in its core.