PWV LIGHT

Radio WavesMicrowavesInfrared LightVisible Light

Ultraviolet Waves

X-Ray WavesGamma

Waves

ELECTROMAGNETICSPECTRUM

The electromagnetic spectrum includes radio waves, microwaves, infraredlight, visible light, ultraviolet light, x rays, and gamma rays. Visible light,which makes up only a tiny fraction of the electromagnetic spectrum, is theonly electromagnetic radiation that humans can perceive with their eyes.

RADIO WAVES ARE LIGHT

Radio wave image showing the Extra-galactic Radio Source Cygnus A

RADIO WAVES ARE LIGHT

Radio wave image showing the Arc at the Galactic Center.

RADIO WAVES ARE LIGHT

The Supernova Remnant Cas A (Radio wave image).

MICROWAVE LIGHT

This image shows microwave background radiation which is a remnant of the Big Bang origin of the Universe.

INFRARED LIGHT

NASA Infrared Telescope Facility. Image of heat radiation from Jupiter.

INFRARED LIGHT

Two infrared images of a volcanic eruption on Io - one of Jupiter's moons. The second image, taken seven days after the first image, reveals that the eruption has decreased in intensity.

VISIBLE LIGHTVisible light ranges from about 4,000 angstroms to 7,000 angstroms. In fact, the colors that make up visible light, like red, blue and green, also have their own ranges of wavelength. Take a look at the diagram below to see what these ranges are. Colors next to each other blend together, so the numbers are only approximations of where the spectrum shifts into the next color. Remember, the numbers are telling you how long the wavelength of each type of light is. The light with shorter waves, like violet and blue, are more energetic than the light with longer wavelengths such as red.

VISIBLE LIGHT

Look at the visible light spectrum at the left. At what wavelength does green merge into yellow? If a star is producing light that is 4,200 angstroms in wavelength, what type of light is coming from this star? As you increase this star's output to wavelength's that measure 5,000 angstroms, then 6,000 angstroms, at what point(s) does the star's light change colors? Can you make a guess at the wavelength that visible light coming from a "Red Giant" star falls into?

VISIBLE LIGHTVolcanic eruption on Io in visible light. Io is one of the moon's of Jupiter. Io was discovered by the scientists Galileo and Marius in 1610 (more than 300 years ago!) However, more moons around Jupiter have been discovered since 1610; some of them discovered only a short time ago.

VISIBLE LIGHTThis is a true color composite (visible light) of the full disk of Jupiter. All features of this image are cloud formations in the Jovian atmosphere, which contain small crystals of frozen ammonia and traces of colorful compounds of carbon, sulfur and phosphorous.

VISIBLE LIGHT

Hourglass nebula around a dying star. This is a visible light image of MyCn18 - a planetary nebula located about 8,000 light years away from Earth.

ULTRAVIOLET LIGHTVisible light can be seen through an optical telescope, however, many types of light are "captured" or "detected" in different ways. One way is by having light pass through a metal or plastic foil filter which only lets a certain range of light through. For instance, the light that forms this image passed through a filter which only allows light with wavelengths in the range of 70-90 Angstroms to go through. 70-90 Angstroms are wavelengths of extreme ultraviolet light.

ULTRAVIOLET LIGHTShown is an

ultraviolet image of the spiral galaxy M101, showing giant star formation regions (bright areas).

ULTRAVIOLET LIGHT

Extreme Ultraviolet image of the crescent Moon.

ULTRAVIOLET LIGHTThe Cygnus Loop (also called the "Veil Nebula") is believed to be the remains of a star which went supernova (exploded) about 150,000 years ago. The original gaseous matter ejected when the star exploded has rammed into surrounding interstellar matter, which is here visible as broken, wispy, nebulous rings.

X-RAY LIGHT

X-ray image of the Crab Nebula supernova remnant with the pulsar off (left) and on.

X-RAY LIGHT

X-ray image of the center region of our Galaxy.

GAMMA RAY LIGHT

Shown is a gamma ray image of the Orion molecular cloud complex.

GAMMA RAY LIGHTGamma ray image

showing Geminga (above and left of center) and the Crab nebula, two bright sources of gamma rays.

Our knowledge about distant stars, planets, solar systems, and galaxies comes from studying the light they emit. When astronomers speak of "light" from stars and galaxies, they include more than just the type of light you see with your eyes. For scientific purposes, different types of light are given different names, which are hidden in the puzzle on this slide.