Astronomy!Astronomy!

Emily Cunningham

Institut d’Astrophysique de Paris

What do astronomers study?What do astronomers study?

1. Planets1. Planets

2. Stars2. Stars

Image: NASA

BLACK HOLE!SUPERNOVA! (NASA)

3. Galaxies3. Galaxies

Andromeda Galaxy (M31). Image: NASA

4. Clusters of Galaxies4. Clusters of Galaxies

Abell Cluster of Galaxies. Image: NASA

5. The Universe: Cosmology5. The Universe: Cosmology

How do astronomers study the How do astronomers study the universe?universe?

How do astronomers study?How do astronomers study?

1. Observations: Telescopes

2. Theory: Computer Simulations and Models

ObservationsObservations

1. Ground-Based

Kitt Peak National Observatory, Arizona, United States

ObservationsObservations

1. Ground-Based

Keck Telescopes: Mauna Kea, Hawaii, United States

ObservationsObservations

2. Space-Based

Hubble Space Telescope (HST)

Thierry Cohen, www.newyorktimes.com

Thierry Cohen, www.newyorktimes.com

2. Theory: Computer Simulations!2. Theory: Computer Simulations!

The Speed of LightThe Speed of Light

Speed of light: c = 3.00 x 108 m/s Because light has a finite speed, the light

that reaches us from distant objects was emitted many (i.e. millions or billions) years ago

This means, in astronomy, looking far away is the same as looking back in time!

Night vision goggles can see infrared!

X-rays pass through your skin but not your bones!

Pinwheel Galaxy: Visible Light (Hubble Space Telescope)

Pinwheel Galaxy: Infrared (Spitzer Space Telescope)

Pinwheel Galaxy: X-Rays (Chandra X-Ray Observatory)

Pinwheel Galaxy: Infrared + Visible + X-ray

Elliptical GalaxiesElliptical Galaxies

Image: Hubble Space Telescope

Image: Hubble Space Telescope