1. Planetary Nebulae Stellar Evolution Part III Dr. Bill Pezzaglia 1
Updated March 23, 2009

2. According to CNN the world will end2
I. Introduction
According to CNN the world will end
Dec 21, 2012

3. As usual, they got it wrong3
As usual, they got it wrong
The world will end:
Dec 21, 5,000,002,012
The sun will….

4. 4
Planetary Nebulae
Introduction
Discovery
Spectra
Evolution
Summary

5. II. Discovery Messier’s Catalog Herschel names them5
II. Discovery
Messier’s Catalog
Herschel names them
Nebular Hypothesis Interpretation

6. A. Messier Catalog 6
Charles Messier ( ) was hunting for comets. People kept reporting the same fuzzy blobs that were NOT comets, so from he made a catalog of about 100 of these fuzzy things to “ignore”.
In fact, these 110 objects are nebulae, star clusters and galaxies, which are the best things to look for in an amateur telescope!

7. The Summer Triangle Cygnus M57 (1779) The Swan Ring Nebula Lyra
Deneb
Cygnus
The Swan
Vega
M57 (1779)
Ring Nebula
In Lyra
1’ in diameter
Made of stars?
Lyra
The Harp
M27: July 12, 1764
Dumbbell Nebula
In Vulpecula
6’ in diameter
Aquila
The Eagle
Altair

8. (accidentally!) by William Herschel using a 6 inch telescope
B : Uranus Discovered 8
(accidentally!) by William Herschel using a 6 inch telescope

9. Herschel Classifies Nebulae9
Catalog of 1000 objects
another 1000 objects
another 500 objects
Classifies objects into star clusters and nebulae. The “types” were:
Bright Nebulae
Faint Nebulae
Very faint Nebulae
Planetary Nebulae (Uranus-like in color & shape)
Very large Nebulae
Very compressed and rich star clusters
Compressed clusters of small and large (i.e., faint and bright) stars
Coarsely scattered clusters of stars

10. C. Nebular Hypothesis 10
Herschel (1786) thought that “Planetary Nebulae” might be a cloud of gas coalescing into a star to be surrounded by planets (hence the name)
“Nebular Hypothesis” had been theoretically proposed earlier (1734 Swedberg, 1755 Kant)

11. III. The Message in the Light11
III. The Message in the Light
Atomic Spectra Lines
Huggins & Nebulium
Central Stars are White Dwarfs

12. A.1. Dark Line Spectra 1802 Wollastan sees lines in solar spectra12
1802 Wollastan sees lines in solar spectra
1814 Fraunhofer Labels them A, B, C, D
Later measures over 500 lines!

13. A.2. Solar spectrum 13

14. A.3. Bright Line Spectra 14
1857 Bunsen’s burner, a clean flame with no color
1859 Kirchhoff suggest using it to study spectra of elements in flame
Each element has a unique set of “bright line” (emission) spectra

15. A.4. Kirchhoff’s Laws 15

16. B. 1786 Herschel discovers: 16 Draco the Dragon Ursa Major
H IV 37 (NGC6543)
Cats Eye Nebula
Ursa Minor
Polaris

17. B.2 William & Margaret Huggins17
(1864) Spectra of Cat’s Eye Nebula shows single emission line in green
Implies it’s a gas, NOT made of stars (which would have absorption lines)
Unknown element “Nebulium” makes greenish color

18. Tom Lehrer: Elements

19. B.2 William & Margaret Huggins19
(1864) Spectra of Cat’s Eye Nebula shows single emission line in green
Implies it’s a gas, NOT made of stars (which would have absorption lines)
Unknown element “Nebulium” makes greenish color
(1926) Bowen shows Nebulium is really Oxygen & Nitrogen under extraordinary conditions

20. C. Central Star: White Dwarf!20
1800 Friedrich von Hahn discovers central star of Ring Nebula (very faint)
Central Stars have Hydrogen, Helium and sometimes Carbon & Oxygen lines.
1918 Wright identifies as type “O” [VERY HOT 125,000 C], hence must be very very small to be so faint!

21. IV. Evolution & Age Age of Planetary Nebula21
IV. Evolution & Age
Age of Planetary Nebula
Distance to Planetary Nebula
Did it explode?

22. A. Exploded Stars 22
(1956) Iosif Shklovsky proposes that red giant stars explode and form a planetary nebular
In 100 years, M27 has expanded 2”
Today it is 5’=300” in size
How old is it?
(300”)(100 yr/2”)= 15,000 years

23. B.1. Doppler Effect with Sound23
1842 Christian Doppler shows “detected” frequency fd depends upon:
fs frequency of source
v relative speed between detector and source
c velocity of sound in medium
So if moving 10% speed of sound towards you, the frequency will be increased 10%

24. B.2. Doppler Effect with Light22
Amount of shift of color is proportional to speed: v/c = /
A 10% shift in wavelength means 10% speed of light

25. C.1. Size of Dumbbell (1970) Dumbbell has Doppler shift of 0.01%25
(1970) Dumbbell has Doppler shift of 0.01%
(0.0001)c=(0.0001)(300000km/s)=30 km/sec
In 1 year expands:
In 15,000 years has expanded to size:
Billion km
15 trillion km (1.5 light year)

26. C.2. Distance to Dumbbell Recall the “parallax triangle”26
Recall the “parallax triangle”
Hence if the size is 100,000 AU and makes an angle of 300”, how far away is it?
333 parsecs

27. Review 27 First Planetary Nebula Discovered was (a) Ring Nebula
(b) Cats Eye Nebula
(c) Double Helix Nebula
(d) Dumbbell Nebula
(e) Orion Nebula

28. Vega
Lyra
The Harp

29. Type: Planetary Nebula
Cats Eye Nebula 6
Type: Planetary Nebula
Where: DRACO

30. Type: Planetary Nebula
Dumbell Nebula 6
Catalog: M27
Type: Planetary Nebula
Where: VULPECULA

31. Type: Planetary Nebula
Double Helix Nebula 6
Type: Planetary Nebula
Where: AQUARIUS

32. Type: Planetary Nebula
Hourglass Nebula 6
Type: Planetary Nebula
Where: MUSCA

33. Review 33 First Planetary Nebula was discovered by (a) Huggins
(b) Herschel
(c) Fraunhofer
(d) Messier
(e) Kant

34. Review 34 Age of a planetary nebula is about (a) 100 years
(b) 10,000 years
(c) 100,000 years
(d) 10 Million years
(e) 10 Billion years

35. Review 35 Size of a planetary nebula is about (a) 1 AU (b) 1 km
(c) 1 light year
(d) 1000x size of sun
(e) 1 MPC

36. 36
Review
4. Planetary Nebula (a) are the disk of material left over from a star formation that will form its planets (b) are made of a close group of stars that are hard to resolve
(c) Are exploded stars
(d) are a nebula that has yet contracted to form a star (e) Are Uranus-like planets

37. V. Summary 37 Discovered by Messier (first one M27)
Herschel interprets as planetary systems forming

38. 2
VI References
Historial M27
Huggins
History: