Life cycle of a star!............ how it forms and how it dies - what happens in between!

1. The life cycle of a star

3. The very basic Driving force for the
Formation and Development of stars is…

4. Gravityand nuclear fusion reactions!

5. Stars with different masses
Grow and Change throughout
the different stages of their lives.

6. The life cycle for a particular
star depends on its size.

7. Two ways a star life cycle varies
depending on Star:
 mass and size almost same as our Sun!
 mass and size far greater than our Sun!

8. All stars begin their life in the same way.

9. How STAR is formed!

10. A cloud of Dust and Gas, known as
a Nebula, becomes a Protostar,
Star forming Nebula protostar

11. protostar
Then, Protostar goes on to
become a Main Sequence Star.
sequence star

12. After Protostar, stars adopt different
ways depending on their Mass & Size.

13. for Stars of size similar to our
Sun!

14. Interstellar Cloud
[Star forming
Nebula]
Small StarProtoStar Red Giant
Star
Planetary
Nebula
White Dwarf
Small & MediumMass Star [same mass of
our sun]
Black Dwarf

15. redgiantstar whitedwarf blackdwarf
In summary…

16. Stars that are far greater in mass than
our Sun follow the path depicted:

17. Interstellar Cloud
[Star forming
Nebula]
Large StarProtoStar Red Super
Giant Star
Supernova
Black Hole
Neutron Star
HighMass Star
[>>> 10 times mass of our sun]

18. redsupergiantstar supernova
blackhole
In summary…
Neutronstar
OR
Formationof neutronstar, or a blackhole (depending on star-
size)

19. Two Processes together…

20. Life cycle of Star!

21. Some Facts!

22. nebula
Massive clouds of dust and gas
in space, is known as a nebula.

23. nebula
Nebula is the precursor
of star-birth.
Nebulae are mostly
composed of Hydrogen.

24. When Gravity starts pulling the Dust
and Gas together within Nebula.
nebula
STAR-Birth begins…

25. As the mass falls together
from Nebula, it gets hot.
Protostar

26. Protostar
When the masses are hot enough…

27. Protostar
Fusion reaction of Hydrogen
nuclei starts to make Helium.

28. The fusion process releases huge
energy keeping the star-core very hot.
Protostar

29. …and Birth of a starbegins!

30. This is the stable phase
in the life of a star!
Main sequence star

31. Main sequence star
Gravity Force holding
the star together!

32. And is balanced by higher pressure
due to Star-core high temperatures.
Main sequence star

33. Main sequence star
The Sun is said to be
at its stable phase!

34. When all the Hydrogen used
up in the fusion process…
Red giant star
larger nuclei begin to form!

35. Red giant star
The star expands to become a red giant.

36. When all the nuclear reactions are
over, a small star like the Sun…
White dwarf
begins to contract under
the pull of Gravity.

37. White dwarf
And, the star becomes a white dwarf
which fades and changes color as it cools.

38. Thanks for watching