X-Ray UltravioletVisibleInfraredRadio The Electromagnetic Spectrum and the Universe.

X-Ray Ultraviolet Visible Infrared Radio

Different wavelengths of the electromagnetic spectrum such as light and radio waves are used to gain information about distances and properties of components in the universe

Radio Waves and the Universe

Many astronomical objects emit radio waves

Astronomers can make pictures from the radio waves being emitted

Radio telescopes use a large metal dish to help detect radio waves

By studying the radio waves, astronomers can learn about the composition, structure, and motion of objects

Radio astronomy has the advantage that sunlight, clouds, and rain do not affect observations

What do Radio Waves show us?

The above image shows the Carbon Monoxide (CO) gases in our Milky Way galaxy

Radio Waves

Microwaves and the UniverseBecause microwaves can penetrate haze, light rain and snow, clouds and smoke, these waves are good for viewing the Earth from space

Microwaves

Infrared Rays and the UniverseSatellites, like the Infrared Astronomy Satellite (IRAS) look up into space and measure the infrared light coming from things like large clouds of dust and gas, stars, and galaxiesInfrared Universe Exploring the Infrared Universe

Sunflower Galaxy Glows with Infrared Light

Ultraviolet and the Universe We can study stars and galaxies by studying

the UV light they give off

Many scientists are interested in studying the invisible universe of ultraviolet light, since the hottest and the most active objects in the cosmos give off large amounts of ultraviolet energy

Andromeda Galaxy in Ultraviolet

X-Rays and Gamma Rays and the Universe

Many things in space emit X-rays, among them are black holes, neutron stars, binary star systems, supernova remnants, stars, the Sun, and even some comets!

This radiation has such high energy that specially made, angled mirrors must be used to help collect this type of light

X-Rays and Gamma Rays and the Universe

X-ray and gamma-ray astronomy has led to the discovery of black holes in space, and has added much to our understanding of supernovae, white dwarfs and pulsars

High-energy observations also allow us to study the hottest regions of the Sun's atmosphere

The Beautiful Universe

Exploring the Universe through Gamma Rays

Gamma Rays and the UniverseFermi Gamma Ray Telescope

Spectral Analysis

We can’t always get a sample of a piece of the Universe

- So we depend on light !

Spectrographs

Astronomers use spectrographs to gather information about stars, including their chemical compositions and temperatures

Chemical Composition

Chemical elements in a star’s atmosphere absorb light from the star

Each element absorbs light at different wavelengths, and each absorbed wavelength appears as a dark line on a spectrum

By comparing a star’s spectrum with the known spectrums of different elements, we can determine which elements are found in stars

Hydrogen

Temperatures The amount of energy

each of these elements absorbs depends on the temperature of the star

Stars at different temperatures produce different line spectrums

Astronomers can use line spectrums to find the temperature of stars