1. Objectives
Give a brief overview of how scientists think stars and planets formed.
List and describe evidence from our solar system that supports that overview.
List and describe evidence from outside our solar system that supports that overview.
What is a nebula?
What is a protostar?
Name an excellent example of a star birth region.
Why are the Terrestrial planets dense but the Jovian planets are not?
Name and describe the two most common ways to find exoplanets (1. Doppler Shift a.k.a. radial velocity, 2. Transit).
DEMONSTRATION MATERIALS:
Stool, green spinner and masses
Sunlamp and radiometer

2. How Stars and Planets are Born Birth of Stars Nebular Hypothesis Solar Nebula Theory
Bring paper scraps for attendance questions
Orion video
Star birth simulation video
View the BBC clip at
(when searching, try: Nebular Hypothesis or
Solar Nebula Theory or just birth of stars)
Nasa-Jpl-CalTech

3. Star/Planet Birth Nebula = large gas and dust cloud
From 1609 to early 1900s, almost every faint, fuzzy object was called a nebula.
Modern definition on slide
Plural: nebulae

4. Star/Planet Birth
Piece of nebula contracts due to gravity and shock waves
Often other stars forming at same time from other parts of gas cloud
Shock wave is from a sudden change in pressure, density or temperature, similar to a sound shock wave but not from sound, instead from energy

5. Star/Planet Birth That piece of contracting gas cloud Flattens
Rotates faster

6. Orion Nebula (video clip) - Great example of a Star Birth Region
Orion Nebula is an excellent example of a star birth region – 2:16 video
Handout paper to summarize steps of star/planet birth

7. Star/Planet Birth Center: Most matter Protostar  Star Protostar =
Large object
From contraction/collapse of part of a large gas cloud
Will become a star
Protostar is cooler pre-star seen in infrared
Begins as invisible concentration of gas
Contracts and grows hotter and hidden in cocoon but detectable in infrared
Newborn star becomes visible as it blows the dust cocoon away

8. Star/Planet Birth Disk: Smaller objects stick and collide to form
larger objects

9. Star/Planet Birth Disk: Warmer near protostar
Light elements blown away
Cooler further out
Light elements like H stay around
Water freezes
Big, less dense planets form from H

10. Star/Planet Birth Happens within cocoon of gas and dust
Often bi-polar jets
Read title…happens within…

11. Star/Planet Birth Star Birth
Protostar turns on: Fusion Protostar  Star
Strong stellar winds
Birth of stars when fusion turns on; this can happen throughout nebula, not just at center; need enough mass for fusion to start
Strong stellar winds (star itself and neighbor stars)

12. Star/Planet Birth Nebula cleared: Heavy stuff by Light stuff by
Collisions and close encounters
Planet Birth
Light stuff by
Strong stellar winds
Planet birth from heavy collisions
How a nebula gets cleared: collisions and winds and then looks similar to our solar system
From 1609 to early 1900s, almost every faint, fuzzy object was called a nebula.
Modern definition on slide
Plural: nebulae
Nasa/JPL - Caltech

13. Star/Planet Birth Summary1. 2. 3. 4. 5. 6.

14. Star/Planet Birth Summary
Nebula
Contracts, Flattens, Rotates
Disk with Protostar
Contracts to form Cocoon around Protostar
Solar wind blows Cocoon away and left with Star
Disk forms Planets

15. Star/Planet Birth Star Birth Simulation
1.5 minute video of simulated star birth

16. Evidence for Star & Planet Birth
a. From our solar system b. From outside our solar system

17. Evidence from our Solar System
Model
Today’s Solar System
Sun at center (most of mass)
Sun and planets – not much else
Flat/planar for most part
Preferred direction of rotation and revolution
Composition (Mostly H, He like stars and gas clouds)

18. Evidence from our Solar System
Model
Today’s Solar System
Smaller objects form larger objects
Planet impacts, seen impacts on our moon, Hubble saw asteroid belt collision in 2010

19. Evidence from our Solar System
Model
Today’s Solar System
Smaller objects form larger objects
Meteoroids and comets
Craters

20. Craters
Moon Craters observation

21. Moon

22. Manicouagan Crater, Quebec, Canada; 215 million years old; largest visible caused by 5 km/3 mi meteorite (thought to be 6th largest); most visible ring is 40 mi wide with larger less visible ring at 60 mi wide

23. Mars

24. Gaspra http://www2.jpl.nasa.gov/galileo/images/gaspra.gif 12 mi X 7 mi
Cratered asteroid in asteroid belt
12 mi X 7 mi

25. Miranda (moon of Uranus)
Big collision on Miranda
Miranda (moon of Uranus)

26. Craterers
Comets
Meteoroids
Comet image

27. Comet Tempel 1 Size ~ 1/2 Manhattan (14kmX4km)
Probe crashed into comet
Size ~ 1/2 Manhattan (14kmX4km)
Size: ~1/3 Manhattan ~8kmX5km
Impacted on July 4, 2005 by part of the NASA Deep Impact probe

28. Evidence from our Solar System
Model
Today’s Solar System
Asteroid belt
Kuiper Belt
Oort Cloud

29. Distant leftovers – Asteroid belt Kuiper Belt Oort Cloud
Credit: NASA/JPL-Caltech/T. Pyle (SSC)

30. Evidence from our Solar System
Model
Today’s Solar System
Smaller objects form larger objects
Meteoroids and comets
Craters
Asteroid Belt, Kuiper Belt, Oort Cloud
Mini “systems” like Saturn and Jupiter

31. Evidence from our Solar System
Model
Today’s Solar System
Terrestrial vs. Jovian planets
Outer solar system is cooler
Big, less dense planets form from H
Frost line where inside of it only metal and rock can condense; outside of it gases condense and Jovian can take on H and He condensing; rocky planets actually took longer time to form and collect more mass from collisions

32. Rotation and Revolution
How does rotation and revolution happen?
Everything is in motion.
Random motion causes pockets of rotation/revolution.
Why so fast?
Angular momentum demo
Can do demo standing on spinning platform with weights in hands and then pull arms in to go faster and stretch arms out to stop/slow down

33. Collisions, close encounters and solar wind clear nebula
Demo – Crooke’s radiometer
Video explanation
Light pressure demo with sunlamp/light bulb and radiometer; temperature and pressure difference – black
The thermal difference in the silver and black sides makes it spin
Video is for at home watching – explanation of how Crooke’s radiometer works

34. Evidence from our Solar System
Model
Today’s Solar System
Smaller objects form larger objects
Meteoroids and comets
Craters
Asteroid Belt, Kuiper Belt, Oort Cloud
Mini “systems” like Saturn and Jupiter
Terrestrial vs. Jovian planets
Rotation and revolution

35. Evidence for Star/Planet Birth
a. From our solar system b. From outside our solar system
Now outside SS

36. Evidence from beyond our solar system
Gas clouds in Milky Way (H, He)

37. Pipe Nebula Pipe Nebula – dark area in lower left

38. Dark absorption nebula: Molecular Cloud Barnard 68

39. Horsehead Nebula in Milky Way and Orion

40. Orion constellation with nebula labels
200 to 1300 ly away
M78 is Reflection Nebula (M or Messier object, 110 of them)

42. Orion Nebula – star birth!
1300 ly away

43. North America nebula on left and Pelican nebula on right separated by dark absorption cloud (two emission nebulae, host star excites nearby gas)

44. Witch Head Nebula

45. http://apod.nasa.gov/apod/ap121101.html with Rigel
Witch Head reflection (starlight scatter from dust) nebula near Rigel in Orion, 900 ly
with Rigel

46. Stars form in groups from the same gas cloud
Pleiades, 7 Sisters, M45
In constellation Taurus
All about same age, 100 million years ago
Open cluster, hot blue stars with high luminosity

47. Stars form in groups from the same gas cloud
Star cluster in constellation Sagittarius

48. M33
Strong stellar winds sculpt the nebulae Recall Crooke’s Radiometer Demo
Triangulum Galaxy

49. 50 ly across 4,500 ly away, Monoceros Nebula
Rosette Nebula
Monoceros nebula and constellation
50 ly across 4,500 ly away, Monoceros Nebula

50. Trifid Nebula - http://antwrp.gsfc.nasa.gov/apod/ap971208.html
3 dark clouds for trifid: Red emission nebula (excited atoms from recapture of electrons) and blue reflection nebula
Trifid Nebula -

51. Part of Trifid

52. Evidence from beyond our solar system
Gas clouds in Milky Way (H, He)
Stars form in cocoons
With bipolar jets

53. Cocoons from Hubble

54. Stars form in cocoons
With bipolar jets

55. Stars form in cocoons
With bipolar jets

56. Cocoons on edges of this nebula; Carina Nebula, stellar nursery 7500 ly away
Sun to Oort Cloud is 100,000 AU = 1.87 LY

57. Infrared Spitzer view of west coast of Mexico in North America nebula – star birth area

58. http://www. spitzer. caltech

59. Evidence from beyond our solar system
Gas clouds in Milky Way (H, He)
Stars form in cocoons
With bipolar jets
Disks of material around stars

60. Disks of material around stars

61. Disks of material around stars

62. Disks of material around stars

63. Evidence from beyond our solar system
Gas clouds in Milky Way (H, He)
Stars form in cocoons
With bipolar jets
Disks of material around stars
Strong stellar winds sculpt birthing gas clouds

64. Strong stellar winds sculpt birthing gas clouds

66. M16 Eagle Nebula

67. Cloud broke off from (part of) Carina Nebula; imagine:  it could be perceived as a superhero flying through a cloud, arm up, with a saved person in tow below

68. Evidence for Star/Planet Birth from Beyond Our Solar System
Gas clouds in Milky Way (H, He)
Stars form in cocoons
With bipolar jets
Disks of material around stars
Strong stellar winds sculpt birthing gas clouds
Exoplanets

69. Exoplanets NASA Exoplanet Archive 11/1/2016
3,402 Confirmed Planets 575 Multi-Planets Systems 4,696 Kepler Candidates
Kepler Spacecraft
2009 to look for Earth-like planets
in the Milky Way Galaxy
Kepler uses a Photometer and the transit method to find planets; launched in 2009

71. How to Find Planets Transit (most common)
Doppler Shift (aka Radial Velocity)
Others:
Direct Imaging, taking pictures
Gravitational microlensing
Astrometry, miniscule movements
Transit method (306 planets discovered) used to be the most common but now it is Radial Velocity (536 planets discovered)
Astrometry, miniscule movements lead us to believe there is a planet 9 but not confirmed or found yet; also due to trans-Neptunian object locations
Website has a great video representation of the 5 methods

72. Finding a planet – Transit
Planets can block a little light from their parent star causing a slight dip in the light
Searching for shadows

73. Finding a planet – Doppler Shift
Planets tug on their parent stars causing a slight wobble in the star
Watching for wobble

74. First visible light picture of an exo-planet (from Hubble)! - 2008
Explanation: Fomalhaut (sounds like "foam-a-lot") is a bright, young, star, a short 25 light-years from planet Earth in the direction of the constellation Piscis Austrinus. In this sharp composite from the Hubble Space Telescope, Fomalhaut's surrounding ring of dusty debris is imaged in detail, with overwhelming glare from the star masked by an occulting disk in the camera's coronagraph. Astronomers now identify, the tiny point of light in the small box at the right as a planet about 3 times the mass of Jupiter orbiting 10.7 billion miles from the star (almost 23 times the Sun-Jupiter distance). Designated Fomalhaut b, the massive planet probably shapes and maintains the ring's relatively sharp inner edge, while the ring itself is likely a larger, younger analog of our own Kuiper Belt - the solar system's outer reservoir of icy bodies. The Hubble data represent the first visible-light image of a planet circling another star.

75. Exoplanet Missions Kepler – transit method Spitzer – infrared
Hubble – visible
CoRoT – ESA decommissioned - transit
Ground Based Telescopes
Future: TESS (2017) and JWST (2018)
Kepler – 2006
Spitzer – 2003 with other missions too
CoRoT – first dedicated mission in 2006
TESS – Transiting Exoplanet Survey Satellite (NASA)
JWST – James Webb Space Telescope (NASA)

76. Jupiter’s mass is over 300 times that of Earth; 10 times the diameter; about 12 Earth years to revolve ~ 4000 days (Earth is at mass and 365 days)
Show where Jupiter is and where Earth is on plot

77. Tutorials on temperature and solar system
Earth

78. Exoplanets - Outside Our Solar System
Many other planets are being found
HUGE NEWS, SEVEN EARTH-SIZED WORLDS ORBITING A RED DWARF, THREE IN THE HABITABLE ZONE
TRAPPIST-1 planetary
system, about 40 LY
away with a cooler, red
dwarf star (12x less
massive than our sun)
E, f, g are habitable – Earth-like & could have liquid water; largest solar system found yet (outside ours); star is a little larger than Jupiter
The initial discovery was made by TRAPPIST, the TRAnsiting Planets and PlanetesImals Small Telescope. Additional planets were subsequently identified using TRAPPIST and the Spitzer space telescope, the Very Large Telescope, UKIRT, the Liverpool Telescope and the William Herschel Telescope.

79. Sunset Part 2 10 Observation Points Started Tuesday, Mar. 28
Due: Apr. 25
Read details on class website about what to turn in for full credit.

80. Homework & Updates
Watch this BBC clip about exoplanets:
Observations: Star Gazing, Telescopes & Moon Craters (60 pt.)
March 30, tonight, Eisenhower Community Center, Hopkins, MN
Need reservation and ask a worker to show you some constellations in the sky
April 1, Saturday, Baylor Park, Eagle Lake Observatory, Norwood-Young America, MN
Raquel will be there about 8-9pm. Find her with the lit-up clipboard. If you miss me, have a volunteer at a telescope sign your paper.
April 4 & 6, Tuesday & Thursday, Jackson Middle School, Champlin, MN
April 7, Friday, Bell Museum, University of MN, Minneapolis, MN
Times and directions on class website
Observation Option: Univ. of MN Public Lectures – Only Do 1!
Tues, Apr 4, 7pm, Bell Museum, Exploring the Mysteries of the Sun: Explosions on our Closest Star (find Raquel for 10 points)
Thur, Apr 20, 7pm, Ted Mann Concert Hall, A Deeper Understanding of the Universe from 1.2 miles Underground (find Raquel for 10 points)
View the BBC clip at

81. Test 2 Results Multiple Choice curved by 2 points Average: 78%
Test questions posted at front and on office doorway
Check for Scantron mistakes
One student got 100%