L1 Sun's Structure PDF

Name __________________________________________________Date __________ Hour _____ Unit 2: Stars and Planetary Systems Earth Science L1: Sun’s Structure Unit Driving Question: How do stars affect the planets around them? Inquiry Question: What is the structure of a star and how does that structure...

Name __________________________________________________Date __________ Hour _____ Unit 2: Stars and Planetary Systems Earth Science L1: Sun’s Structure Unit Driving Question: How do stars affect the planets around them? Inquiry Question: What is the structure of a star and how does that structure affect the planets around it? Section 1: Introductory Video The Sun: Crash Course Astronomy #10 https://www.youtube.com/watch?v=b22HKFMIfWo Section 2: The structure of the Sun Read & Annotate Our sun is a middle-aged, medium sized star, big enough to hold a million Earths. The ancient Greeks thought the Sun was a perfect sphere of fire. Today we know that the Sun is a variable star - a star whose brightness changes because of its rotation. We also know that it produces life giving light and heat as well as harmful radiation. Although the average distance from the Earth to the sun is 149,000,000 kilometers, careful observations from the Earth have revealed a surprisingly large number of different visible features such as sunspots, solar flares, and prominences. The sun is a complex and dynamic object with a multi-layered structure. At its heart lies the core, a region of immense pressure and temperature where nuclear fusion takes place. Here, hydrogen atoms fuse together to form helium, releasing enormous amounts of energy in the process. This energy, primarily in the form of gamma rays, begins its long journey outward through the sun's layers. Surrounding the core is the radiative zone, a region where energy is transported through radiation. Photons, the particles of light, emitted from the core, are absorbed and re-emitted by the dense plasma in this zone. This process is incredibly slow, with photons taking hundreds of thousands of years to traverse the radiative zone. As they move outward, they gradually lose energy, transitioning from high-energy gamma rays to lower-energy X-rays and eventually visible light. The outermost layer of the sun's interior is the convective zone. Here, energy is transported through convection currents, similar to the boiling of water in a pot. Hot plasma rises to the surface, cools, and then sinks back down, creating a continuous cycle of upwelling and downwelling. This convective motion is responsible for the granular appearance of the sun's surface, with each granule representing a region of rising hot plasma. The visible surface of the sun, known as the photosphere, is where the energy generated in the core finally reaches the outside world. It is a relatively thin layer of gas, approximately 400 kilometers deep and has a temperature of about 5,500 degrees Celsius. The photosphere is not a solid surface like Earth's, but rather a layer of ionized gas that emits light. Sunspots, darker, cooler regions on the photosphere, are caused by intense magnetic activity. These spots vary in size and can be larger than Earth. The number of sunspots varies over an 11-year cycle and can have a significant impact on space weather, or the energy and matter emitted by the sun. Above the photosphere lies the sun's atmosphere, which consists of several layers. The chromosphere is a relatively thin layer of gas that is typically only visible during a total solar eclipse. It is heated by the energy from below and is the site of intense magnetic activity, leading to solar flares and prominences. Solar flares are sudden, intense releases of energy, while prominences are large, arching structures of plasma that can extend thousands of kilometers into space. It is characterized by a reddish hue and is the site of many dynamic phenomena, including solar flares  and prominences. Solar flares are intense bursts of radiation and particles that can disrupt Earth's magnetic field and cause radio blackouts. Prominences are large, arching structures of plasma that can extend thousands of kilometers into space. The outermost layer of the sun's atmosphere is the corona. It is a vast, tenuous region of extremely hot plasma that extends millions of kilometers into space. The corona is much hotter than the sun's surface, reaching temperatures of millions of degrees Celsius. This high temperature is thought to be caused by the sun's magnetic field, which can accelerate particles to high speeds. The corona is the source of the solar wind, a continuous stream of charged particles that flows outward from the sun and fills the entire solar system. The corona is only visible during a total solar eclipse or through specialized instruments that can block out the bright light from the photosphere. Discussion Questions 1.​ What is the primary process that occurs in the sun's core, and what is the significance of this process for life on Earth? the primary process that occurs in the suns core is nuclear fusion which is where, hydrogen atoms fuse together to form helium, releasing enormous amounts of energy in the process. the significance of this process for life on earth is the fact that there is light from the sun from this. 2.​ Create a model that shows how energy travels through the radiative zone. Why does it take so long for photons to escape this region? there is a dense plasma and when the energy hits the photons is is absorbed and re-emited in a different direction which makes them bounce in many different directions and take a long time. 3.​ What is the photosphere, and why is it considered the "surface" of the sun? What are sunspots, and how do they form? the hotosphere is the atmosphere of the sun which is also the visible part so it is considered the surface of the sun.The photosphere is not a solid surface like Earth's, but rather a layer of ionized gas that emits light. Sunspots, darker, cooler regions on the photosphere, are caused by intense magnetic activity. 4.​ How does the temperature of the corona compare to the temperature of the photosphere? Why is the corona so much hotter, and how is it heated? the corona is much hotter than the earths surface. which is caused by the sun's magnetic field and accelerates particles at high speeds. 5.​ Create a model that shows the similarities and differences of the energy transport mechanisms in the radiative and convective zones. What are the implications of these differences for the sun's overall energy output? The implications of these differences for the suns overall energy output are the amount f time it takes for the light to be seen because it takes almost 17,000 years to go through the radioactive zone and then it has to go through currents of hot and cooled gas in the convection zone. 6.​ Hypothesize on how changes in the sun's magnetic field might influence the formation and behavior of sunspots? What might the potential consequences of these sunspots be for Earth?  if the magnetic field were to change to more or less magnetic the formation of sun-spots might became more or less frequent. So when the magnetic field increases pressure the suns temperature decreases forming more sunspots. 7.​ If nuclear fusion in the sun's core were to cease, what would be the immediate and long-term consequences for Earth and its inhabitants? there wounldnt be any energy left to create heat and eventually there would be no heat left and the earth wouldn’t be inhabitable. 8.​ Some scientists hypothesize that the sun's activity cycles influence Earth's climate. Evaluate the evidence for and against this hypothesis, considering the potential mechanisms and the limitations of current knowledge. the captivity of things like magnetic pressure can cool down the sun which would hypothetically affect the temperature of the earth. But, it takes so long for the energy to be seen and in the radioactive part f the sun the energy gets mixed up so there may not be any correlation at all. Section 3: Sun’s Structure Model Objective ​ Develop an understanding of the structure of the Sun by constructing a scale model of a slice of the Sun. Materials ​ 3 pieces of paper ​ 100 cm long string ​ Meter stick ​ Colored Pencils ​ Pencil​ ​ Transparent Tape Procedure Part 1: Making the Slice 1.​ Tape the pieces of paper together end to end (long-ways). Overlap the pieces of paper by about 0.5cm and place the tape on the backside of the model (tape on one side, then flip over for the next steps). 2.​ Fold the paper in half lengthwise to find the center of the page. This crease will serve as your “centerline.” You can draw a dashed line along this crease, but it is not necessary. 3.​ On the centerline, 1 cm from the left edge, make a small dot to represent the ‘center of the Sun’ 4.​ To establish the width of the 15° slice, measure 69.6 cm from the ‘center of the Sun’, then from that point, measure 8.3 cm from the centerline in both directions and make small dots. 5.​ Next, make two lines connecting the ‘center of the sun’ to those points, extending the lines to the far edge of the paper. See figure below. Part 2: Determining the Layers of the Sun to Scale 1.​ The scale that you are to use is 1 cm to 10,000 km. Convert the radius to scale for each layer of the Sun. Layer Upper Radius Convert Radius to Color pScale (1 cm = 10,000 km) Center of Sun 0 0 - Core 175,000 km 17.5 cm Red Radiation Zone 557,012 km 55.7012 cm White Convection Zone 696,265 km 69.6265 cm Purple Photosphere 697,070 km 69.7070 cm Yellow Chromosphere 699,070 km 69.9070 cm Blue Corona 1,390,000 km End of Paper Orange 2.​ Next, make a mark on the centerline 17.5 cm from the center of the sun. Using the string as a guide (loop it around a pencil if that works for you), place the pencil at the 17.5 cm point, hold the other end at the point marked ‘center of the sun’, and draw an arc to mark the outer boundary of the core. 3.​ Repeat for the rest of the layers. Measuring from the center of the sun outward for each layer. Draw the arc for each layer from the center of the page to the edge of the slice at the corresponding measurement. Part 3: Finishing the Slice 1.​ Color each layer according to the key in the above table. 2.​ Draw in each of the three solar features: sunspots, solar flares, and prominences. Be sure to draw them where they belong. 3.​ Cut out the slice, put your name(s) in the corona and turn in. Slices will be put together to create a full sun.