The Stars-Blog Entry

1-What is a star?

Stars are balls in the stars, so far away from us! They made of dust and gasses from very big clouds called stellar nebula. There are many different stars. Stars are classified by colors, temperature, size, luminosity, ages, and spectral class. Stars have different colors such as blue, red, yellow, orange, and red. Stars temperatures’ are different, either very hot or cool. Stars also have different sizes small, medium, and large stars. Luminosity is how bright a star is. Stars can be bright stars, medium, and dim stars. CAN YOU BELIVE THAT A STAR HAS AGE? Yes all the stars have different ages. There are young stars, middle ages stars, and old stars! Spectral class is a letter that scientists use to tell the temperature of a star.

2- Types of stars.

There are four different types of stars: Super giant, giant, main sequence, and white dwarf. The super giant stars are huge, hot and bright stars. Giant stars are large cold and bright stars, they also have different colors. Main sequence stars have different colors different sizes and different temperatures. They also have different luminosity, so bright, bright or dim. White dwarf stars are small, old, hot and dim stars.

3- H-R Diagram.

What does H-R stand for? H-R stands for Hurtzsprung-russell. H-R Diagram is a letter that astronomers use to classify stars based on their temperatures’, luminosity, colors, and size. It also shows the relationship between the characteristics of a star and the star type.

3- Nuclear fusion.

 Stars are gigantic fireplace! in these gigantic stars a lot of things happens to make it that hot and that big. one of those things is nuclear fusion.What is a nuclear fusion? Nuclear fusion is when a reaction happens in the nuclear of a star and changes 2 hydrogen molecules into 1 helium molecule and energy. 

2H→He+ Energy.

                       

4- Life cycle of a star.

Stars were created long time ago. They have life and ages! Stars were born from giant clouds that got smaller and hotter because of the gravity this process called stellar nebula. All the stars are made of Stellar Nebula. There are different types of stars with different life cycles. Stars types are 3 Sun-like a star which its life cycle is Red giant, Planetary Nebula, White dwarf, then black dwarf. Another type is huge stars. Its life cycle is Red supergiant, Supernova, then Neutron star. Last is the giant stars, its life cycle is Red super giant, Super nova, then Black hole.