The document discusses the Milky Way galaxy and its discovery and mapping over time by various astronomers from Galileo to Hubble. It then covers theories about galaxy formation from collapsing dust clouds and collisions. Finally, it describes different types of galaxies like elliptical, spiral, and starburst galaxies and lists some examples, as well as the parts that make up a typical galaxy.

1. What does it consist?

5. Milky Way-“Galaxies kuklos”

6.  Galileo
-Numerous stars

7.  18th century-
William and
Caroline Herschel
- Mapped the
distances of stars

8.  1781-Charles
Messier
- Cataloged various
nebulae

9.  20th century-
Harlow Shapely
- Measures the
distributions and
locations of globular
star clusters.

11.  1924- Edwin
Hubble
-Resolved that the
spiral nebulae had
structures and stars
- CEPHEID
VARIABLES.

12. II. FORMATION AND EVOLUTION

13. Ideas about the origins and
evolutions:
• collapsing dust clouds = formation
of galaxies
• collisions between galaxies

14. Two assumptions:
1. Filled with hydrogen and helium
2. Some areas were slightly denser
than others
EARLY UNIVERSE THEORIES

16. Two factors:
• Angular momentum (degree of spin)
• Cooling

17. III. DISTRIBUTION OF GALAXIES

26. INTERGALACTIC MEDIUM
Space between galaxies and clusters of
galaxies

27. THE DOPPLER EFFECT

28. IV. GALAXY TYPES AND PARTS

31. Messier 32: a dwarf elliptical (E2) satellite
galaxy of the Andromeda Galaxy

32. Messier 87: giant elliptical (E1) at the Virgo Cluster's core. It
has grown very large by ``eating'' other galaxies.

33. NGC 2997: a large face-on spiral galaxy
(Sc)

34. Messier 81: a large spiral galaxy (Sb).

35. The Triangulum Galaxy (=M 33): a small spiral galaxy (Scd) in the
Local Group

36. NGC 1365: a barred spiral galaxy (SBbc)

37. NGC 3351 (=M 95): a barred spiral galaxy (SBb).

38. Messier 82: a starburst galaxy

39. V. PARTS OF A GALAXY