Class Update• Observations• Friday, Mar. 27 8-9:30pm University of Minnesota (Telescopes, Star

Gazing, & Moon Craters) Print Verification Sheet from calendar• Saturday, Mar. 28 7-10pm Eagle Lake Observatory at Baylor Park

(Telescopes, Star Gazing, & Moon Craters) Print Verification Sheet• Thursday, May 7 5:30-8:30pm Science Museum of Minnesota SPACE

exhibit free. Details in email sent last week.• Safe Sun Observation

• Do the prep work. Different assignments for lecture-only and lab students. Details on class website. Handout on back table. Have ready by Mar. 31 – this coming Tuesday.

• Mar. 31 (most likely), Apr. 2, Apr. 7 or Apr. 9 – Watch email for date• All lecture and lab students need to come on this date• Lecture for the day and lab for the week• ~8:30am to 3:30pm reserve 30 minutes for lecture or 1 hour for lab

• Test 2 – not finished grading yet• Scantron multiple choice score on website soon• Writing assignment score on website by Tuesday

How Stars and Planets are Born

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

Video Clip – Orion Nebula, Star Birth Region

http://www.spitzer.caltech.edu/video-audio/381-hiddenuniverse026-Orion-Nebula-Gallery-Explorer-

Star/Planet Birth

• Center:

Most matter

Protostar Star

Protostar =o Large object o From contraction/collapse of

part of a large gas cloudo 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 awayCooler further out

Light elements like H stay aroundWater freezesBig, less dense planets form from H

Star/Planet Birth

• Happens within cocoon of gas and dust

• Often bi-polar jets

Star Birth• Protostar turns on: Fusion

Protostar Star• Strong stellar winds

Star/Planet Birth

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• 1.• 2.• 3.• 4.• 5.• 6.

Star/Planet Birth Summary1. Nebula

2. Contracts, flattens, rotates

3. Disk with Protostar

4. 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 Simulationhttp://www.youtube.com/watch?v=YbdwTwB8jtc&playnext=1&list=PLFC84C8CBA3C1B6D6&feature=results_video

Evidence forStar/Planet Birth

a. From our solar systemb. From outside our solar system

Evidence from our

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)

Model Today’s Solar System

Evidence from our

Solar System

• Smaller objects form larger objects Model Today’s Solar System

Evidence from our

Solar System

• Smaller objects form larger objects • Meteoroids and comets• Craters

Model Today’s Solar System

• Craters

http://www2.jpl.nasa.gov/galileo/images/gaspra.gif12 mi X 7 mi

Gaspra

Miranda (Uranus)

Craterers

• Comets

• Meteoroids

Size ~ 1/2 Manhattan (14kmX4km)

Comet Tempel 1

http://apod.nasa.gov/apod/ap110216.htmlSize: ~1/3 Manhattan ~8kmX5kmImpacted on July 4, 2005 by part of the Deep Impact probe

Evidence from our

Solar System

• Asteroid belt• Kuiper Belt • Oort Cloud

Model Today’s Solar System

• Credit: NASA/JPL-Caltech/T. Pyle (SSC)

Distant leftovers –

Asteroid belt

Kuiper Belt

Oort Cloud

Evidence from our

Solar System

• Smaller objects form larger objects • Meteoroids and comets• Craters• Asteroid Belt, Kuiper Belt, Oort Cloud• Mini “systems” like Saturn and Jupiter

Model Today’s Solar System

Evidence from our

Solar System

• Terrestrial vs. Jovian planetsOuter solar system is coolerBig, less dense planets form from H

Model Today’s Solar System

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

• Light pressure demo – radiometer

• Demo • Video• https://www.youtub

e.com/watch?v=llxqNcipTwA

Evidence from our

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

Model Today’s Solar System

Evidence forStar/Planet Birth

a. From our solar systemb. 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 lefthttp://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 light pressure demo

Rosette N

ebula

50 ly across 4,500 ly away, Monoceros

Trifid Nebula - http://antwrp.gsfc.nasa.gov/apod/ap971208.html

Part of Trifid

• Gas clouds in Milky Way (H, He)

• Stars form in cocoons

• With bipolar jets

Evidence from beyond our solar system

• 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-North-America-Nebula-Disappears

http://www.spitzer.caltech.edu/images/3511-ssc2011-03c-Babies-in-the-North-America-Nebula

• Gas clouds in Milky Way (H, He)

• Stars form in cocoons

• With bipolar jets

• Disks of material around stars

Evidence from beyond our solar system

• Disks of material around stars

• Disks of material around stars

• Disks of material around stars

• 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

Evidence from beyond our solar system

• 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

http://exoplanetarchive.ipac.caltech.edu/

NASA Exoplanet Archive 3/5/20151,821 Confirmed Planets

463 Multi-Planets Systems4,175 Kepler Candidates

Kepler Spacecraft2009 to look for Earth-like planets

in the Milky Way Galaxy

http://exoplanetarchive.ipac.caltech.edu/

How to Find Planets

• Transit (most common currently)• Doppler Shift (aka Radial Velocity)• Others:

http://planetquest.jpl.nasa.gov/page/methods

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 a planet (from Hubble)! - 2008

http://antwrp.gsfc.nasa.gov/apod/ap081114.html

Exoplanet Missions

• Kepler – transit method• Spitzer – infrared• Hubble – visible• CoRoT – ESA decommissioned - transit• LBTI – Large Binocular Telescope

Interferometer – in Arizona

http://exoplanetarchive.ipac.caltech.edu/

Earth