PRESENTATION ON TYPES AND LIFE CYCLE OF STARS, TYPES OF GALAXIES AND NEBULAE AND BLACK HOLES, SUITABLE FOR MIDDLE AND SENIOR SCHOOL STUDENTS

2. Stars - Spheres of
plasma emitting heat
and light and held
together by gravity

3. Measuring Cosmic
Distances
• Light Year =Distance traveled
by light in one year
• ONE LIGHT YEAR
• Parsec  3.26 light years
kmx 12
105.9

4. THEY ARE BORN
ALIKE BUT DIE
DIFFERENT

5. NEBULAE
THE CRUSIBLES
OF CREATION
Mammoth
clouds of
dust, hydr
ogen and
helium

6. A GAS AND DUST
NEBULA
The breeding ground
of stars

7. PILLARS OF CREATION
DENSE STAR
FORMING REGIONS
IN EAGLE NEBULA

8. HORSE HEAD -
A DARK
NEBULA IN
ORION
AN ASTRAL
HORSE

9. A CRAB IN THE
HEAVENS
REMNANT OF 1054 CE
SUPERNOVA
EXPLOSION
IN TAURUS

10. A NURSERY
FOR THE
YOUNG
STARS
TRIANGULUM
EMISSION
NEBULA

11. PLANETARY
NEBULAE
(Formed
from Red
Giants)

12. GRAVITATIONAL
COLLAPSE
The
moments
of
creation

13. NUCLEAR
FUSION
THE NUCLEAR
REACTION THAT
FUELS THE STARS
H
H
H
H He ENERGY

14. BORN IN FIRE….
A STAR TAKES BIRTH AT
THE CENTRE OF A
NEBULA

15. BETULGUSE
- A RED GIANT
NEARING ITS END
(0.4 – 2.25 solar mass)

16. WHITE DWARF
(Sirius B)
Core mass - up to
1.4 solar masses
(Chandrasekhar
Limit)

17. BEGINNING OF THE END
(>1.4 solar mass)
EXPANDING REMNANT
EMITS XRAYS, VISIBLE LIGHT AND RADIO
WAVES AND MAY TURN INTO A PULSAR

18. SUPERNOVA
- STAR THAT DIES WITH A
BANG

19. THE LARGEST
EVER….CAPTURED BY
‘CHANDRA’
SUPER NOVA 2006, A STAR 150
TIMES MASSIVE THAN SUN

20. NEUTRON STAR
(pulsar 1.4 – 3.2
solar mass)

21. BLACK HOLES
(10 – 25 solar masses)
The Ultimate Trap

22. Point of no
return
No rest
zone

23. THE REMAINS
OF DEAD
STARS…
MATERIAL FOR SECOND
GENERATION STARS
COSMIC
REBIRTH

24. LIFE CYCLE OF STARS

25. SUN
- THE
NEAREST
STAR

26. Bio data
• The star nearest to the earth
(150 m. km away)
• A gaseous mass of hydrogen and
helium
• It has 99% the mass of the solar system
• It is 330,000 times heavier than the
earth
• It is 109 times wider than the earth

27. • Rotates on its axis once in 25
days
• Revolves around the centre of
our galaxy with a speed of
220km/sec
• Cosmic year = 220million years
• Light takes 8 minutes to reach
earth

28. OPEN
CLUSTER
A PEER GROUP
OF STARS

29. SEVEN SISTERS
AN OPEN CLUSTER

30. GLOBULAR
CLUSTER
A SPHERICAL GROUP
GOING AROUND THE
GALACTIC CENTRE

31. GALAXIES
THE COLOSSAL
COLONIES OF
STARS

32. BILLIONS…

33. …AND BILLIONS OF
THEM…..

34. CLASSIFICATION
GALAXIES
SPIRAL ELLIPTICAL IRREGULAR

35. SPIRAL GALAXY

36. BARRED SPIRAL

37. ELLIPTICAL GALAXY
NGC 4150
– 45 MILLIION LY AWAY

38. IRREGULAR
GALAXY

39. RING
GALAXY

40. LENTICULAR
GALAXY
A LEVIATHAN LENS

41. MILKY WAY - A PANORAMIC
VIEW
OUR HOME TURF

42. Spitzer IR image of Sagittarius A - The super
massive black hole at the center of our
galaxy
AT ITS HEART

43. MILKY
WAY
ABOUT 30 GALAXIES
WITHIN 4 MILLION
LIGHT YEARS

44. LOCAL
GALECTIC
GROUP

45. POSITION OF
THE SUN

46. Milky Way
• Diameter  (30,000 parsecs)
• Average thickness 5000 light
years (1533 parsecs.)
• Thickness at the centre  13,000
light years (4000 par.)
ly5
10

47. Milky Way
• Distance of the sun from the
centre 30,000 light years
(10,000 parsecs)
• Av. Distance between the stars 
5 light years (1.6 parsecs)

48. ANDROMEDA
A neighbor too far…
2.5 million ly away
Largest in the local group

49. The nearest spiral
galaxy which is …..
ANDROMEDA
in IR by Spitzer

50. …….on a collision
course
HeadingtowardsMilky
Wayat140km/h

51. CLASH OF THE
TITANS
COLLISSION OF
GALAXIES

52. SMALL MEGALLENIC
CLOUD
One of the satellite
galaxies 200,000 ly
away

53. LARGE
MEGALLENIC
CLOUD
A satellite galaxy
1,63,000 light years
away

54. The next
door
neighbor..
Just 25,000 ly away.
Discovered in 2003
Canis
Major
Dwarf
Trail of the dwarf
galaxy

55. THE NEAREST
A dwarf
galaxy
cannibalized
by Milky Way

56. SAGITTARIUS
DWARF
An Elliptical
Galaxy
70,000 ly away

57. QUASARS – Quasi
Stellar Radio Sources
The most distant and
the most ancient….