Unit 4 The Sun Basic Sun Information Energy Formation & Layers of the Sun Surface Features of the Sun

Basic Sun Information Vocab Words that go along with Basic Sun information…. Magnetic Field

The planets relative to each other! Basic Sun Information The planets relative to each other!

Sun relative to the planets! Basic Sun Information Sun relative to the planets!

The sun relative to other stars! Basic Sun Information The sun relative to other stars!

Fun Sun Data *All data is approximate Diameter 1,391,940km Circumference 4,379,000 Radius 695,970km Mass 1.989 x 1030 kg Temp. at Core 15,600,000 K ≈ 15599727 °C Temp. at Surface 6400 K ≈ 6127 °C Rotation Period 25 days in middle, 35 day near poles Luminosity 3.85 x 1026 watts – we use 1 on our HR diagram because we compare other stars to the sun! Absolute Magnitude 4.83 Apparent Magnitude -26.7 Spectral Class G Type Star – means it is yellow! Spectral Type G2 V Solar Constant 1400 watts/m2

Basic Sun Information The Sun is an average sized star. It looks very big from earth because it is so close to us! Why do we study the sun? Sun is very important to earth – without its heat and light, we would not be able to survive! Gives us the Seasons Its gravity keeps us, and the other planets, in orbit It is the nearest star to us! We study it to learn about other stars. It provides earth with A LOT of energy! Changes in solar activity or surface features effect our climate, atmosphere, weather & power transmissions!

Basic Sun Information Sun is “relatively” stationary, at the center of our Solar System The Milky Way revolves as a whole, but relative to earth the sun is stationary! It does rotate around itself. The center latitudes take 25 days to rotate, while areas near the poles take 35 days to rotate.

Basic Sun Information The Sun is located on one of the arms of our Milky Way Galaxy

Basic Sun Information Sun is made of 73% Hydrogen, 25% Helium and 2 % other elements. Those other elements consist of 70 different elements! Some of these elements are….. Oxygen, Carbon, Nitrogen, Silicon, Magnesium, Neon, Iron, Sulfur

Basic Sun Information The sun is surrounded by a large magnetic field, which causes most of the activity and features on the sun. A magnetic field is the area sounding an object that displays magnetism, or forces of attraction and repulsion Because of the uneven rotation of the sun, every 11 years the suns magnetic field flips. This means the solar cycle is 22 years, because it takes that long for the magnetic field to flip-flop back to where it began!

Energy Formation & Layers of the Sun Vocab Words that go along with Energy Formation & Layers of the Sun Hydrogen Fusion Neutrino Core Radiation Zone Convection Zone Photosphere Chromosphere Corona Photon

Energy Formation & Layers of the Sun Energy for the sun is produced in the core of the sun! It is produced by a process called Hydrogen Fusion Hydrogen Fusion is when two Hydrogen atoms actually bond together to form Helium and give off energy For this process to occur there has to be an EXTREME amount of heat and pressure, which is what the core of the sun has! This process can not currently occur on earth

Energy Formation & Layers of the Sun The sun uses the “fusion” process for energy production, not the “fission” process!

Energy Formation & Layers of the Sun This is a visual representations of the Hydrogen Fusion process. Hydrogen atoms bond together to make Helium & Energy. They also give off a neutrino, which is a neutral byproduct of the hydrogen fusion reaction!

Energy Formation & Layers of the Sun The sun is made of 6 layers The inner 3 layers are part of the sun’s interior Core, Radiation Zone & Convection Zone The outer 3 layers are part of the sun’s atmosphere Photosphere, Chromosphere & Corona These layers have distinct roles in energy production of the sun

Energy Formation & Layers of the Sun

Energy Formation & Layers of the Sun 1. Core Where energy is produced 2. Radiation Zone Where energy is “radiated” to after being produced in the core 3. Convection Zone Where energy is circulated to the atmosphere of the sun 4. Photosphere The visible layer of the sun! 5. Chromosphere Region between the Photosphere & Corona 6. Corona Outer most layer of sun’s atmosphere. It is full of Hot and very tenuous gases.

Energy Formation & Layers of the Sun Every photon of energy takes a different amount of time to reach the photosphere from the core. A photon is a particle of energy given off from the hydrogen fusion reaction. On average it takes 20 million years for energy produced in the core to make it all the way to the photosphere of the sun. Once it hits the photosphere, those photons of energy travel at the speed of light and they reach the earth in about 8.5 minutes!

Surface Features Vocab Words that go along with Surface Features…. Sunspot Prominence Solar Flare Solar Wind Sunspot Cycle Granulation

Surface Features There is a constant flow of electrically charged particles, energy and radiation coming off the sun. This is called the Solar Wind. The solar wind travels throughout the solar system and usually does not reach earth because our atmosphere protects us from too much radiation. It does constantly reshape our magnetosphere, which is the part of earth’s magnetic field that is confined by the solar wind.

Surface Features The entire photosphere of the sun is covered in granulation Grainy, rice like look on the surface of the sun This is a result of circulating currents under the photosphere in the convection zone

Surface Features Sunspots occur on the surface of the sun. Sometimes the sun has lots of sunspots, sometimes the sun has very few. Sunspots are dark, coolers areas on the sun’s surface. They are cooler than their surroundings, but still about 4,480°C

Surface Features The number of sunpots goes through a cycle. It reaches a maximum, then falls to a minimum and then climbs back to a maximum again! It takes about 11 years to go through this cycle. This sunspot cycle is directly related to the flip of the sun’s magnetic field!

Surface Features Sometimes, the interaction of the sun’s magnetic field with the magnetic field of a sunspot causes a small explosion off the sun’s surface. If the ejecta is not traveling fast enough, it loops back around forming a Solar Prominence A Solar Prominence is a fiery arch that rises off the sun’s surface Solar Prominences typically form and last for about a day. Sometimes, very stable prominences last a few months.

Surface Features Sometimes, the interaction of the sun’s magnetic field with the magnetic field of a sunspot causes a small explosion off the sun’s surface. If the ejecta is traveling fast enough, it escapes the sun’s gravitational pull and forms a Solar Flare. A Solar Flare is a sudden, tremendous, explosive outburst of light, invisible radiation and material from the sun. Solar Flares usually only last a few minutes, but can sometimes last a few hours.

Surface Features An increase in the amount of sunspots (at sunspot maximums) generally means an increase in Solar Prominences and Solar Flares. It is important for us to follow the Sunspot cycle to know when there is going to be an increase in Sunspots, because they cause Solar Flares and Prominences

Surface Features How do Solar Flares effect earth? They release a great amount of radiation that will eventually travel to earth. They cause the Northern Lights or Aurora Borealis In the Southern Hemisphere, they have the Southern Light or Aurora Australis This radiation can disrupt radio signals and communication with satellites and space crafts. This radiation can cause geomagnetic storms. Heats & expands upper atmosphere of earth, which can effect space shuttle reentry and the space station orbiting the earth. Earth’s magnetic field can be disrupted causing compasses to work differently. Atmospheric storms can cause satellite damage, power surges and/or blackouts