Download Birth of Stars and Planets

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).
How Stars and Planets are Born
Birth of Stars
Nebular Hypothesis
Solar Nebula Theory
Nasa-Jpl-CalTech
Star/Planet Birth
Nebula =
large gas and dust cloud
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
Star/Planet Birth
That piece of contracting gas
cloud
• Flattens
• Rotates faster
Orion Nebula (video clip)
- Great example of a Star Birth Region
http://www.spitzer.caltech.edu/video-audio/381hiddenuniverse026-Orion-Nebula-GalleryExplorer-
Star/Planet Birth
• Center:
Most matter
Protostar  Star
Protostar =
o Large object
o From contraction/collapse of
part of a large gas cloud
o Will become a star
Star/Planet Birth
• Disk:
Smaller objects stick
and collide to form
larger objects
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
Star/Planet Birth
• Happens within
cocoon of gas
and dust
• Often bi-polar jets
Star/Planet Birth
Star Birth
• Protostar turns on: Fusion
Protostar  Star
• Strong stellar winds
Star/Planet Birth
• Nebula cleared:
– Heavy stuff by
Collisions and close encounters
• Planet Birth
– Light stuff by
Strong stellar winds
Nasa/JPL - Caltech
Star/Planet Birth Summary
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1.
2.
3.
4.
5.
6.
Star/Planet Birth Summary
1.
2.
3.
4.
Nebula
Contracts, Flattens, Rotates
Disk with Protostar
Contracts to form Cocoon
around Protostar
5. Solar wind blows Cocoon
away and left with Star
6. Disk forms Planets
Star/Planet Birth
Star Birth Simulation
http://www.youtube.com/watch?v=YbdwTw
B8jtc&playnext=1&list=PLFC84C8CBA3C1
B6D6&feature=results_video
Evidence for
Star & Planet Birth
a. From our solar system
b. From outside our solar system
Evidence
from our
Solar System
Model
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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)
Evidence
from our
Solar System
Model
• Smaller objects form larger objects
Today’s Solar System
Evidence
from our
Solar System
Model
• Smaller objects form larger objects
• Meteoroids and comets
• Craters
Today’s Solar System
• Craters
Gaspra
http://www2.jpl.nasa.gov/galileo/images/gaspra.gif
12 mi X 7 mi
Miranda (moon of Uranus)
Craterers
• Comets
• Meteoroids
Comet Tempel 1
Size ~ 1/2 Manhattan (14kmX4km)
http://apod.nasa.gov/apod/ap110216.html
Size: ~1/3 Manhattan ~8kmX5km
Impacted on July 4, 2005 by part of the NASA Deep Impact probe
Evidence
from our
Solar System
Model
• Asteroid belt
• Kuiper Belt
• Oort Cloud
Today’s Solar System
Distant
leftovers –
Asteroid belt
Kuiper Belt
Oort Cloud
•
Credit: NASA/JPL-Caltech/T. Pyle (SSC)
Evidence
from our
Solar System
Model
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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
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
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
• Collisions, close
encounters and
solar wind clear
nebula
• Demo – Crooke’s
radiometer
• Video explanation
• https://www.youtub
e.com/watch?v=llx
qNcipTwA
Evidence
from our
Solar System
Model
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•
•
•
•
•
•
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
Evidence for
Star/Planet Birth
a. From our solar system
b. From outside our solar system
Evidence from beyond our
solar system
• Gas clouds in Milky Way (H, He)
http://apod.nasa.gov/apod/ap990224.html
• Pipe Nebula
Pipe Nebula – dark area in lower left
http://apod.nasa.gov/apod/ap970621.html
http://apod.nasa.gov/apod/ap990511.html
http://wordlesstech.com/wp-content/uploads/2010/12/orion-over-snowy-ireland3.jpg
http://apod.nasa.gov/apod/ap131231.html
Orion
Nebula
– star
birth!
http://www.telescopes.cc/m42.htm
http://antwrp.gsfc.nasa.gov/apod/ap060816.html
http://apod.nasa.gov/apod/ap121101.html with Rigel
Stars form in
groups from
the same gas
cloud
http://antwrp.gsfc.nasa.gov/apod/ap060403.html
Stars form in
groups from
the same gas
cloud
M33
Strong stellar
winds sculpt the
nebulae
Recall Crooke’s
Radiometer
Demo
Rosette Nebula
50 ly across 4,500 ly away, Monoceros Nebula
Trifid Nebula - http://antwrp.gsfc.nasa.gov/apod/ap971208.html
Part of Trifid
Evidence from beyond our
solar system
•
Gas clouds in Milky Way
(H, He)
• Stars form in cocoons
• With bipolar jets
• Stars form in cocoons
• With bipolar jets
• Stars form in cocoons
• With bipolar jets
http://hubblesite.org/newscenter/archive/releases/2010/13/image/a/
http://www.spitzer.caltech.edu/images/3513-ssc2011-03b-NorthAmerica-Nebula-Disappears
http://www.spitzer.caltech.edu/images/3511-ssc2011-03c-Babies-in-the-North-America-Nebula
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
• Disks of
material
around
stars
• Disks of
material
around
stars
• Disks of
material
around
stars
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
• Strong stellar winds sculpt birthing gas clouds
http://antwrp.gsfc.nasa.gov/apod/ap030630.html
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
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
http://exoplanetarchive.ipac.caltech.edu/
http://exoplanetarchive.ipac.caltech.edu/
How to Find Planets
• Transit (most common)
• Doppler Shift (aka Radial Velocity)
• Others:
http://planetquest.jpl.nasa.gov/page/methods
– Direct Imaging, taking pictures
– Gravitational microlensing
– Astrometry, miniscule movements
Finding a planet – Transit
• Planets can block a little light from their
parent star causing a slight dip in the light
http://kepler.nasa.gov/Mission/faq/
Finding a planet – Doppler Shift
• Planets tug on their parent stars causing a
slight wobble in the star
http://planetquest.jpl.nasa.gov/page/methods
First visible light picture of an exo-planet (from Hubble)! - 2008
http://antwrp.gsfc.nasa.gov/apod/ap081114.html
Exoplanet Missions
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Kepler – transit method
Spitzer – infrared
Hubble – visible
CoRoT – ESA decommissioned - transit
Ground Based Telescopes
Future: TESS (2017) and JWST (2018)
Earth
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
• http://www.universetoday.com/133556/huge-news-seven-earth-sizedworlds-orbiting-red-dwarf-three-habitable-zone/
TRAPPIST-1 planetary
system, about 40 LY
away with a cooler, red
dwarf star (12x less
massive than our sun)
Sunset Part 2
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10 Observation Points
Started Tuesday, Mar. 28
Due: Apr. 25
Read details on class website about what
to turn in for full credit.
Homework & Updates
• Watch this BBC clip about exoplanets:
http://www.bbc.co.uk/programmes/p009gxf2
• 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)
Test 2 Results
• Test questions
posted at front
and on office
doorway
• Check for
Scantron
mistakes
Test 2 Grades
Number of Students
• Multiple
Choice curved
by 2 points
• Average: 78%
30
17
14
9
A
B
C
Letter Grade
D