X-Ray UltravioletVisibleInfraredRadio The Electromagnetic Spectrum and the Universe

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 Universe Because 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 Universe Satellites, 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 galaxies Infrared 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 Universe Fermi 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