LIFE OF STARS By Juan Rodríguez and Jose Vera
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