Life of a Star

What is a star?
I s a sphere made of hot gas.

Types of stars:
-Giant stars
-Supergiant stars
-Main sequence stars
-White dwarfs stars


What is a H-R diagram?
Is a graphical tool that astronomers  use to classify stars according to their luminosity, spectral type, color, temperature and evolutionary stage.

What is nuclear fusion?
Is the process by which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus.

The life cycle of a star:
From its formation in a nebula, to its death as a white dwarf or neutron star.
NEBULAA nebula is a cloud of gas (hydrogen) and dust in space.

STAR

Is a sphere made of gas.
RED GIANTThis is a large bright star with a cool surface.

RED DWARF
These are very cool, faint and small stars, approximately one tenth the mass and diameter of the Sun.
WHITE DWARFThis is very small, hot star, the last stage in the life cycle of a star like the Sun.

SUPERNOVA
This is the explosive death of a star, and often results in the star obtaining the brightness of 100 million suns for a short time.

NEUTRON STARS
These stars are composed mainly of neutrons and are produced when a supernova explodes, forcing the protons and electrons to combine to produce a neutron star. 
BLACK HOLESBlack holes are believed to form from massive stars at the end of their life times.