Sun FactsSun Facts
The Sun is rather ordinary when it The Sun is rather ordinary when it comes to stars. comes to stars.
In fact, there are 100 billion stars in In fact, there are 100 billion stars in our galaxy that are similar to the our galaxy that are similar to the Sun. Sun.
What makes our star unique is that it What makes our star unique is that it is is oursours—responsible for light, heat, —responsible for light, heat, and life as we know it. and life as we know it.
Learning ObjectivesLearning Objectives Appreciate the scale of the Sun-EarthAppreciate the scale of the Sun-Earth The sun emits a range of energies that The sun emits a range of energies that
make up the make up the ElectromagneticElectromagnetic EMEM spectrum.spectrum.
The range extends beyond the visible The range extends beyond the visible spectrum in both directions, beyond the spectrum in both directions, beyond the red and beyond the violet. red and beyond the violet. RROOYYGGBBIIVV
The sun is a star that sheds a continuous The sun is a star that sheds a continuous flow of particles (solar wind) and flow of particles (solar wind) and electromagnetic radiation.electromagnetic radiation.
and there’s more folks…and there’s more folks… The Sun’s outer atmosphere is called The Sun’s outer atmosphere is called
the the coronacorona.. During solar storms, huge bursts of During solar storms, huge bursts of
electromagnetic energy are emitted by electromagnetic energy are emitted by solar flaressolar flares
Flares are sometimes accompanied by Flares are sometimes accompanied by Coronal Mass Ejections Coronal Mass Ejections (CMES)(CMES) – – eruptions of particles in the coronaeruptions of particles in the corona
EM energies travel at the speed of EM energies travel at the speed of lightlight
Some solar output is harmfulSome solar output is harmful
What does the Earth get What does the Earth get from the Sun that is from the Sun that is essential to keep us essential to keep us
alive?alive?
What evidence do you have What evidence do you have that there is energy that there is energy
reaching you from the Sun?reaching you from the Sun?
PhotonsPhotons
Light is made up of bundles of energy Light is made up of bundles of energy called called photonsphotons which travel through which travel through space.space.
Each color of light is made of different Each color of light is made of different photon energies.photon energies.
The energy level carried by violet light The energy level carried by violet light is about twice as much as red light.is about twice as much as red light.
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Colors in Visible Light
Electromagnetic Spectrum
Electromagnetic energies travel at the
speed of light
Particles travel at less
than the speed of light
Particles from the Sun
Slower particles
Faster Particles
Low Energy
Very High Energy
Random WalkRandom Walk For the Sun, a photon is generated at For the Sun, a photon is generated at
the center and makes its way to the the center and makes its way to the surface. It may take up to a surface. It may take up to a thousand years to get to the thousand years to get to the surface, and the form of the energy surface, and the form of the energy may change from X-ray to visible may change from X-ray to visible wavelengths. When the photon wavelengths. When the photon leaves the Sun, it takes eight leaves the Sun, it takes eight minutes to get to us at the speed of minutes to get to us at the speed of light. light.
The 8-minute travel time to Earth by sunlight hides a thousand-year journey that actually began in the core.
Sir Fredrick William Sir Fredrick William HerschelHerschel In 1800, Sir Fredrick William In 1800, Sir Fredrick William
Herschel split up sunlight Herschel split up sunlight using a glass prism instead using a glass prism instead of a diffraction grating. of a diffraction grating. Herschel's experiment was Herschel's experiment was important not only important not only because it led to the because it led to the discovery of infrared light, discovery of infrared light, but also because it was the but also because it was the first time that someone first time that someone showed that there were showed that there were forms of light that we forms of light that we cannot see with our eyes. cannot see with our eyes.
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Infrared
Colors in Visible Light
Electromagnetic Spectrum
Electromagnetic energies travel at the
speed of light
Particles travel at less
than the speed of light
Particles from the Sun
Slower particles
Faster Particles
Low Energy
Very High Energy
Ultraviolet or UVUltraviolet or UV
Right of the violet end of the Right of the violet end of the spectrum.spectrum.
Invisible to humansInvisible to humans Bees can see itBees can see it Judging by where ultraviolet energy is Judging by where ultraviolet energy is
located on this spectrum, do you think located on this spectrum, do you think it has more or less energy than visible it has more or less energy than visible light?light?
What have you heard about What have you heard about UV?UV?
Cause sunburnCause sunburn Damage our eyesDamage our eyes Sunscreen and Sunscreen and
sunglasses block itsunglasses block it
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Radio Waves Microwaves Infrared Ultraviolet
Colors in Visible Light
Electromagnetic Spectrum
Electromagnetic energies travel at the
speed of light
Particles travel at less
than the speed of light
Particles from the Sun
Slower particles
Faster Particles
Low Energy
Very High Energy
CD ROMCD ROM
Looking at various wave lengths that Looking at various wave lengths that make up the electromagnetic make up the electromagnetic spectrum.spectrum.
Coronal Mass Ejections Coronal Mass Ejections CMECME
Occasionally, a part of the Sun’s Occasionally, a part of the Sun’s upper atmosphere (upper atmosphere (coronacorona) erupts ) erupts in a giant gust of solar storm in a giant gust of solar storm particles called a particles called a Coronal Mass Coronal Mass Ejection or CMEEjection or CME
Some CMEs are ejected outward from Some CMEs are ejected outward from the Sun in the direction of Earth.the Sun in the direction of Earth.
CMEs often accompany solar flares.CMEs often accompany solar flares.
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Radio Waves Microwaves Infrared Ultraviolet X-Rays Gamma Rays
Colors in Visible Light
Electromagnetic Spectrum
Electromagnetic energies travel at the
speed of light
Particles travel at less
than the speed of light
Particles from the Sun
Slower particles
Faster Particles
Low Energy
Very High Energy
The Culprit in the MysteryThe Culprit in the Mystery
Will CME, EM and solar wind Will CME, EM and solar wind knowledge help decide if the Sun knowledge help decide if the Sun caused the January disruptions in caused the January disruptions in Earth?Earth?
What happened to the Sun at 3:10 on What happened to the Sun at 3:10 on 01/25?01/25?
If the solar flare affected Earth in If the solar flare affected Earth in eight minutes, why did many of the eight minutes, why did many of the mysterious events happen two days mysterious events happen two days later, on 01/27?later, on 01/27?
Is the Sun always sending out both EM Is the Sun always sending out both EM energy and solar wind?energy and solar wind?
How fast does EM energy travel?How fast does EM energy travel? How fast does solar wind travel?How fast does solar wind travel? What happened on the Sun on 01/25?What happened on the Sun on 01/25? What happened on the Earth around What happened on the Earth around
3:18?3:18? What happened on the Earth two days What happened on the Earth two days
later?later? What do you think caused the events What do you think caused the events
on 01/27?on 01/27?