Galaxies

1. Astronomy 101Astronomy 101
GalaxiesGalaxies

2. Galaxy Concept
1755 Immanuel Kant
Vast collections of stars outside the Milky Way

3. William Parsons- (Lord Rosse)
72” scope in 1850’s
Spiral structure in in Hershel’s Nebulae

4. M51

5. 1920 Shapley-Curtis Debate
Curtis
Spiral Nebulae were Island Universes
Shapley
Spiral Nebulae were close objects in our galaxy

6. Hubble 1924
Found Cepheid Variables in M-31
Could Determine Distances

8. Types of Galaxies
Spiral
Barred Spiral
Elliptical
Irregular
Pecular

9. Spiral M81 in Ursa MajorSpiral M81 in Ursa Major

10. Closest spiral is M-31Closest spiral is M-31

11. Where’s Waldo?

12. Barred SpiralsBarred Spirals

13. Milky Way is Barred Spiral
APOD April 23, 2015

14. Elliptical M32 by Greg HigginsElliptical M32 by Greg Higgins

15. Irregular- Colliding GalaxiesIrregular- Colliding Galaxies
What about the stars?What about the stars?

16. M51 by Mike Heim

17. Milky Way and Andromeda
Collision in 6 billion years

18. Peculiar M82
by J &R McCullough

19. Hubble’s Tuning Fork SchemeHubble’s Tuning Fork Scheme

20. Galaxy Clusters

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22. Active Galaxies
Brighter than ordinary galaxies
10% of all galaxies
Talk for another time….

23. Hubble Ultra Deep Field Video