1 passport science space unit – part 1 of 3 powerpoints (textbook reference chapters 12, 13, 14,...
TRANSCRIPT
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Passport ScienceSpace Unit –
Part 1 of 3 PowerPoints
(Textbook reference Chapters 12, 13, 14, 15 and 16)
What is astronomy?
•Stars •Nebula •Planets
•The Sun
•The Great Andromeda Galaxy by George Greaney
•Star clusters •Galaxies
•Galaxy clusters
•Dark matter •Black holes
What is astronomy?
Astronomy is a science that attemptsto understand the make-up and the history of the universe.
Galaxy M83 in Hydraby George Greaney
M33, The Pinwheel Galaxy in Triangulumby George Greaney
What is astronomy? M33, The Pinwheel Galaxy in Triangulum
by George Greaney
Basically, if its off this planet its a study of some realm of astronomy.
As one might imagine that covers an awful lot of subjects, even more than we know right now. •NGC 253, galaxy in Sculptor
by George Greaney
Key Ideas• Galaxies: clusters of stars; different shapes
• Stars: Sun; differ in size, temperature and color; source for all bright objects
• Gravity: planets, stars, solar system
• Know the appearance, composition, position and size, and motion of objects in our solar system
• Astronomical units for measuring
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What is a Meteor?
What is a Comet?
What is a Star?
What is a Nebula?
What is an Open Cluster?
What is a Black Hole?
What is a Quasar?
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Galileo Galilei (1564-1642)
What is an astronomer?
A night watchman with a college education?
Galileo Observatory in Italy
An astronomer is a scientist, skilled in mathematics, physics, and astronomy.
Most professional astronomers work for universities or government agencies.
Source: The Berkeley Cosmology Group
Astronomer Serena Kim at work At Cerro Tololo in Chili
Few astronomers spend much time looking through a telescope. Most operate telescopes from a control room or even from their computer at home via theInternet.
Typical astronomers only spend one or two weeks eachyear observing, and the rest of their research time analyzing their data.
Source: Applied Theoretical and Computational Physics DivisionLos Alamos National Laboratory
Amateurs and their tools
What is an amateur astronomer?
What is an amateurastronomer?
Although the term has different meanings for different people, a basic definition would include anyone who looks into the sky, and wants to see or learn more.
What is space like?
• No air
• No gravity-when you’re not very close to a planet, sun, or moon
• No wind
• No friction
• No real “up” or “down”
• No pressure
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The Expanding Universe 15-5
• The Big Bang Theory
What is a “galaxy”? (Textbook reference 15-4)
• A large group of stars outside of our own Milky Way• Made of billions to trillions of stars
– Also may have gas and dust
• Spiral, or elliptical, or irregular shaped– The Milky Way Galaxy is a spiral galaxy.
Image at http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2007/41/results/50/
Spiral galaxy--Andromeda
NOAO/AURA/NSF Images at http://www.noao.edu/image_gallery/html/im0606.html and http://www.noao.edu/image_gallery/html/im0685.html
Elliptical Galaxies
Images at http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2007/08/image/a/format/large_web/results/50/ and http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/1995/07/results/50/
Irregular Galaxies
NASA and NOAO/AURA/NSF Images at http://hubblesite.org/newscenter/archive/releases/galaxy/irregular/2005/09/results/50/ ,
http://www.noao.edu/image_gallery/html/im0560.html , and http://www.noao.edu/image_gallery/html/im0993.html
Our Galaxy: the Milky Way• has about 200 billion stars, and lots of gas
and dust• is a barred-spiral (we think)• about 100,000 light-years wide (a measure of
distance)• our Sun is halfway to the edge, revolving at
half a million miles per hour around the center of the Galaxy
• takes our Solar System about 200 million years to revolve once around our galaxy
The Milky Way
Image at http://news.nationalgeographic.com/news/bigphotos/1945371.html
Mapping the Milky Way
We can see
– stars
– star clusters
– nebulae
– galaxies
How do we know what our galaxy looks like?How do we know what our galaxy looks like?
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Reviewing Galaxies
• Groups of stars, planets, and space debris
• Irregular, Elliptical, Spiral
• Milky Way is our galaxy
WhatIs aStar?
Image of the Sun from Goddard Space Flight Center
What is a Star?
Our Sun is the closest star.
At the simplest, a star is just a ball of gasthat has condensed out of interstellar material. The largest part of its lifetime is spent as a main sequence star during which hydrogen is being converted to helium balancing gravitational contraction so that the radius and energy output remain almost constant.
Source: The British Astronomical Association
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Stars (Textbook reference 15-2 and 15-3)
• Bodies of gases that give off tremendous amounts of radiant and heat energy
• Constellations are patterns of stars used for navigation, storytelling, honoring heroes
Life Cycle of a Star Video
Image courtesy of Dave DockeryAstronomical Society of Las Cruces Source: The British Astronomical Association
Nearby Stars:
Name Distance from Earth
Sun 93 million miles (8 light minutes) Proxima Centauri 4.22 Light YearsAlpha Centuri A,B 4.39 Light YearsBarnards Star 5.94 Light YearsWolf 359 7.8 Light YearsLalande 21185 8.3 Light YearsSirius A,B 8.6 Light Years
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Evolution of Stars
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How do Black Holes form?
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Black Holes
• Remains of a neutron star that has collapsed due to intense gravity
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Hertzsprung-Russell Diagram
The Doppler Effect:
Red Shift – stars moving away from EarthBlue Shift – stars moving toward Earth
Video on the Hertzsprung-Russell Diagram
Spectroscopy Video
Hertzsprung-Russell Diagram
Images from http://www.nasa.gov/centers/goddard/news/topstory/2007/spectrum_plants.html and
http://sunearthday.gsfc.nasa.gov/2009/TTT/65_surfacetemp.php
The coolest stars are blue-white in color.
Using a Star’s Spectrum• We can use a star’s spectrum to classify it.
NOAO/AURA/NSF image at http://antwrp.gsfc.nasa.gov/apod/ap010530.html