The document discusses the nature and classification of stars, explaining their formation from gas and dust, their life cycle, and how they emit heat and light. It describes various types of stars, their usefulness to humans, and notable constellations. The conclusion emphasizes the power of stars and acknowledges the sun as crucial for life on Earth.

1. NAME : AYUSH SRIVASTAV
CLASS : VIII
SECTION : DAFFODIL
ROLL NUMBER : 8108
SUBJECT : SCIENCE
YEAR 2013-14
DATE OF SUBMISSION : 21ST
GUIDED BY : VISHNU SIR

2. Stars

3. WHAT IS A STAR ?
 A star is a massive, luminous sphere
of plasma held together by its own gravity.

4. CLASSIFICATION OF STARS
 A young star is called a dwarf star. It can be a
yellow star, a white star or a red star.
 Older Stars are called Supergiants. They can be
red star or a blue star.
 Stars are classified according to their temperature
and brightness into two categories :-

5. HOT STARS
 There are two types of hot stars :--

6. BLUE COLOURED STARS

7. WHITE COLOURED STAR

8. COOLER STARS
 There are two types of cooler stars :--

9. RED COLOURED STARS

10. ORANGE COLOURED STARS

11. HOW ARE STARS ARE BORN ?
 Star are formed from giant clouds of dust and gas.
From gravity, the cloud collect to form a rotating
gaseous ball. Once the new star gets hot enough it
begins to create energy from a process called
nuclear fission. This created energy allows the star
to glow for billions of years.

12. WHERE ARE STARS BORN ?
 Stars are Formed in The Eagle Nebula.

13. WHY DO STARS EMIT HEAT AND LIGHT
?
 Stars emit heat and light as they are a big Nuclear
Reactor just like our Sun.

14. WHY DO STARS PRODUCE WHITE
COLOURED LIGHT ?
 Actually stars don’t produce white coloured light
they produce light which is of seven colours present
in the rainbow. They combine to form white
colour, this also happens with the sunlight as the
sun is also a star.

15. WHY DO STARS TWINKLE ?
 Stars twinkle because of the sacks of warm and
cold air present in the atmosphere. Because of
these disturbances in the path of light produced by
the stars they seem to twinkle.

16. WHAT ARE SHOOTING STARS ?
 A shooting star is not a star that falls from the sky it
is just a misconception. The shooting stars are the
meteoroids that burns when comes in the Earth’s
atmosphere.

17. HOW DOES A STAR DIES ?
 A Star dies when it runs out of gases to burn, first it
expands into a red, super giant and it explodes.

18. AFTER THE STAR DIES ?
 When the star dies it forms a Crab Nubela.

19. HOW ARE STARS USEFUL ?
 The stars are useful to the humans in many
ways, as the Sun which provides energy to the
whole Earth. And they also tell us about the
directions.

20. FIRST USE OF STARS
THE SUN
 The Sun is the nearest star to our planet and is the
life source for all the living beings on earth. Without
the sun no life is possible on Earth.

21. LIFE CYCLE OF THE SUN
 Our Sun is an average star. The chart below shows
the lifecycle of our sun over billions of years.

22. END OF THE SUN
 When the sun will die it will form a black
hole and the whole solar system will be
destroyed when sucked into the black hole.
But nothing to worry our sun is an average
star and there are near about billions of
years left for the sun to die.

23. SECOND USE OF STARS
CONSTELLATIONS
 The Stars help us by giving us the knowledge of a
persons future(as believed by some people) and
also give us the knowledge of directions.

24. CONSTELLATIONS
 The stars forming a group that has a recognisable
shape is called a constellation. There are four main
types of constellations:--
 Great Bear or Ursa Major or Saptarshi or Big
Dipper
 Orion or Hunter
 Cassiopeia
 Leo Major

25. URSA MAJOR
 It is the constellation that is found at the early nights
in summer. There are seven constant stars in this
constellation. This constellation ca be used to find
the pole star which is in the north direction.

26. ORION
 Orion is the constellation that ca be seen during
winter in the late evenings. It has eight bright stars.
The three stars in the middle show the belt of the
Hunter. The three stars show the star Sirius.

27. CASSIOPEIA
 It is a prominent constellation seen in the northern
sky during the winter in early night.

28. LEO MAJOR
 Leo is one of the constellation of the zodiac. It
forms a lion in the sky.

29. CONCLUSION
 From this presentation we came to now how
powerful the Stars are. In front of their power we
are nothing. The only thing we can do is to pray to
god for the long life of the Sun.