Deep Space Astronomy

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Deep Space Astronomy

• Unit 7

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Electromagnetic Spectrum

• Electromagnetic Radiation? a wave that occurs in
  space
• Often called light, even though it is not always
  seen by human eyes
• Is classified into 7 categories
• based on the wavelength (motion)
• of the light waves

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Electromagnetic Spectrum

• Electromagnetic spectrum? range of all possible
  electromagnetic radiation

Short wavelength
Long wavelength
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Electromagnetic Spectrum
                                                
                                                  
  ltgt
Danger!
Everything with a temperature gives off
electromagnetic energy. Hotter bodies more
energy from left side.
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Gamma Rays
Moon
Exploding Star
Very short wavelength. Extremely high
energy. Rips apart your DNA.
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X-Rays
Galaxies
Simpson, Homer
Short wavelength. High energy. Does some cellular
damage.
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UV-Rays
UV Rays Movie Clip
Sunburn!
Short wavelength. High energy. Does moderate cell
damage.
Sun
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Visible Light
Our eyes have evolved to see these wavelengths.
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Infrared
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Whirlpool Galaxy
Visible Image
Infrared Image
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Microwaves
Radio
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Whirlpool Galaxy
Visible Image
Infrared Image
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Supernova Explosions
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Big Bang Theory

• Big Bang Theory? model that says the universe
  expanded from a small, hot, dense point that is
  still expanding today
• Think of raisins rising in a loaf bread

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Evidence of Big Bang
Microwave Background Radiation (Leftover Energy)
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Galaxy Shifts

• Analysis of the spectrum of light from distance
  galaxies shows a shift towards longer wavelengths
• Red Shift? longer wavelengths (red wavelengths)
  show that galaxies are moving away from us
• Universe is still expanding
• What would a blue shift show us?

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Red-Shifting of Light
Different Visible Light Spectra
You look through a spectroscope to see different
patterns of light.
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Red-Shifting of Light Universe Expanding
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Edwin Hubble

• Edwin Hubble? Astronomer that discovered that
  other galaxies exist besides our own (the Milky
  Way)
• He also discovered that the farther away from
  Earth a galaxy is, the faster it is red-shifting
• What does this mean? (think of the balloon)

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Hubble telescope

• The Hubble Space telescope? space telescope that
  was sent into Earths orbit in 1990.
• Important in many space discoveries
• Can see above earths atmosphere (clear pictures)
• Saw black holes at the center of galaxies
• Sees the birth of stars in gas clouds
• Has revealed billions of galaxies beyond our own
• Dark matter/energy
• Hubble Discoveries

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Structure of Universe
Universe
Galaxy
Solar System
Sun (Star)
Earth
You
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Universe sub-divisions

• Biggest Universe? everything that exists in
  space (includes all matter and energy)
• May be 12-15 billion years old
• Could be 93 billion light years across
• Is expanding due to the Big Bang

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Universe Sub-divisions cont

• 2nd Biggest Galaxy? large rotating mass of
  stars, dust, and dark matter
• Categorized into 3 categories by their shape
  spiral, elliptical, irregular
• We live in the Milky Way galaxy which is spiral
  shaped

Irregular
Elliptical
Spiral
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The Milky Way Galaxy
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Universe Sub-divisions cont

• 3rd Biggest Solar System? contains the sun and
  other bodies that are gravitationally bound to
  it.
• 8 planets (Mercury, Venus, Earth, Mars, Jupiter,
  Saturn, Uranus, Neptune)
• 166 known moons including our own
• 3 dwarf planets (Pluto, Ceres, Eris)
• Asteroids, meteoroids, comets

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Universe Sub-divisions cont

• Smallest Sun? Our star holding all of our
  planets in its gravity
• We are just a small speck compared to the whole
  universe.

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Star Life Cycles

• Nebula? cloud of dust, hydrogen gas, and plasma
  where stars are formed
• First stage of the stars life cycle
• Gas, dust, and other matter clump together to
  form larger masses (stars)
• The left over matter may form planets

The Horse Head Nebula
The Eagle Nebula
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Nebulas (gas clouds) seen by Hubble
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Star Life Cycle

• Average Star? Our sun is an average sized star
• Average age 5 billion years old
• Average temperature 6,000 degrees F
• Medium brightness

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Star Life Cycle

• Red Giant? stars whose cores heat up and expand
  to 100s of times larger then the sun
• 1,000-10,000 times brighter then the Sun
• This will happen to our sun in 5 billion years

Betelgeuse
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Star Life Cycle

• After the Red Giant phase
• A small or medium sized star becomes a white
  dwarf
• A large star becomes a Supernova
• Then a black hole OR- a neutron star

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Star Life Cycle

• White dwarf? Final evolutionary stage of medium
  sized stars
• Ultimate fate of our Sun
• Small, faint star

Arrow points to Sirius B, a white dwarf next to
an average star, Sirius A
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Star Life Cycle

• After the red giant phase, ONLY large stars
  become supernovas
• Supernova? a large explosion that creates an
  extremely bright burst of energy
• During the supernova, the star emits
• more energy then the sun does in
• its lifetime
• Death of the star

Keplers Supernova of 1604
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Star Life Cycle

• Neutron (pulsar) Star? formed from the collapsed
  remains of a supernova explosion
• Only 20-40 km acrossvery small!
• Rotates around completely in 1-30 seconds (it
  takes earth 24 hours to rotate completely)
• Have magnetic poles that pulse quickly
• like a lighthouse beam of light
• http//www.aip.org/history/mod/pulsar/pulsar1/01.h
  tml

Radio telescopes pick up beams of radiation as
clicking noises when they pass through earth
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Star Life Cycle

• After a supernova explosion, a star can also
  become a black hole
• Black hole? a region of space in which the
  gravitational field is so powerful that nothing
  can escape
• spagettification
• Time slows down
• Time travel??
• http//www.nasa.gov/rss/universe_vodcast.rss