Life of stars

LIFE OF STARS

By Juan Rodríguez and Jose Vera

Index

• Clasification of stars.......................3• Birth of stars.....................................4• Live of stars......................................6• Death of stars...................................10

Types of stars

Birth of stars

• A nebula contracts and forms a protostar.• The protostar becomes a star.

Main sequence

• It‘s the larger period about 90 % of stars lifetime.

Giant star

• In this stage the star starts fusing helium into oxygen and carbon.

• Its size is normally 100 times its size in main sequence.

Supergiant stars

• In this stage stars creates the rest of the elements until nickel.

• Only stars with, at least, 8 times the mass of the Sun reach this phase.

Planetary nebula

• At the end of a giant star strong stellar winds speel its outer layer to the space.

White dwarf

• Is the residual nucleus of the star after the explosion.

• It does not performe nuclear reactions.

Supernova

• The nucleus collapse and explodes.• Here are produced the rest of the elements.• They are streamly bright.

Black hole

• After the supernova the remaining nucleus of the start collapse and forms a black hole.

• It occurs when the remaining nucleus hae more than 3 times the mass of the Sun

Neutron star

• If the remaining nucleus have got less than 3 times the mass of the Sun.

• It‘s extremelly dense.

Bibliography

• https://map.gsfc.nasa.gov/universe/rel_stars.html• https://www.nasa.gov/audience/forstudents/9-

12/features/stellar_evol_feat_912.html• http://solarviews.com/eng/starformation.htm• http://www.astronomynotes.com/evolutn/

chindexb.htm• www.universetoday.com• oneminuteastronomer.com