Stellar Birth Jade J Rachael H Stages of

Stellar Birth Jade J Rachael H

Stages of Stars • In the birth of a star there are seven stages in it’s formation. • A star's life is a constant battle against gravity, and pressure support. That battle begins as soon as a molecular cloud begins to collapse into a protostar.

Interstellar Clouds • Name given to an accumulation of gas, plasma and dust. • Denser than the average region of interstellar medium.

Collapsing Cloud Fragment • At this phase the cloud is very diffuse, so heat is not trapped so the temperature does not build up.

Fragmenting Ceases • Several tens of thousands of years after the collapse of the cloud the center becomes opaque and the temperature rises greatly. • The cloud typically begins to shrink in size and the appearance of a potostar can be seen at the center.

Protostar • At this stage the cloud begins to collapse on its self increasing the temperature and causing it to contract.

Protostar Evolution • As the protostar moves past stage four it moves closer to the main sequence. • This stage is characterized by violent surface activity and strong protostellar winds.

Newborn Star • The temperature has now become high enough for thermonecular fusion to begin • This results in somewhat lower luminosity

Main Sequence • The star contracts a bit more and enters into hydrostatic equilibrium. • During the main sequence lifetime, the star achieves stability by gas pressure.