For a region within a nebula to begin forming a star, gravity must win the tug-of-war against what opposing force?

Answer

Internal gas pressure

Star formation initiates when the inward gravitational pull in a dense pocket overcomes the outward thermal pressure or internal gas pressure that tries to keep the cloud expanded.

For a region within a nebula to begin forming a star, gravity must win the tug-of-war against what opposing force?
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