Spring 2001: The Sun. Equipment:! This write-up, calculator, lab notebook! Data you downloaded from the SOHO website

Size: px
Start display at page:

Download "Spring 2001: The Sun. Equipment:! This write-up, calculator, lab notebook! Data you downloaded from the SOHO website"

Transcription

1 Our Sun is a middle-aged, medium sized star, big enough to hold a million Earths. The ancient Greeks thought that the Sun was a perfect sphere of fire. Today we know that the Sun is a variable star that produces life giving light and heat as well as harmful radiation. It causes space weather that can harm astronauts working in space and can interfere with satellites orbiting our planet and communications. In this exercise, you will learn the basic features of the Sun s surface, atmosphere, and interior, and begin to understand what causes some of these features. You will be introduced to sunspots and the solar cycle and calculate the rotation of the Sun. Objectives:! Identify basic solar features and read about what causes some of them! Understand what sunspots are, what the solar cycle is, and how the Sun moves Equipment:! This write-up, calculator, lab notebook! Data you downloaded from the SOHO website Figure 1. Artist s rendition of solar structure. Page 1 of 8

2 I. FEATURES OF THE SUN S SURFACE AND ATMOSPHERE Although the average distance from Earth to the Sun is a whopping 149,600,000 kilometers (93,000,000 miles), careful observation from Earth reveals a surprisingly large number of different visible features. Figure 1 is an artist s schematic of the Sun. The most obvious and best known feature is the sunspot. Typically moving in groups, these dark, planet-sized features have been known to humankind for centuries. As sunspots form and disappear over periods of days or weeks, they also appear to move across the Sun s surface because the Sun rotates. Caused by strong magnetic fields, sunspots are shaped much like a horseshoe magnet that rises from below the Sun s surface. The rising hot gas is trapped by the sunspots intense magnetic field, which cools the sunspots from 6000 C to about 4200 C. The cool area appears dark compared to the area around it. Thus, from Earth, we see spots on the Sun (Figure 2). In some photographs, we can also see light colored areas around groups of sunspots that resemble tufts of cotton candy. We call these fluffy looking fringes, plages (Figure 3). Figure 2. Visible Sun. Visible or white-light images of the Sun show the photosphere and sunspots. Sunspots are regions of intense magnetic fields. They appear dark because they are somewhat cooler than the surrounding gas. Figure 3. H-alpha Sun. Light from hydrogen gas just above the photosphere shows the bright plages that surround the active sunspot regions. Dar kstrong-like filaments are also seen that are in fact prominences seen head-on. The bright structures on the limb are prominences. Sunspots are the sources of massive releases of energy (called coronal mass ejections) as well as solar flares (Figure 4), the most violent events in the solar system. In a matter of minutes to several hours, a solar flare releases about 10,000 times the annual energy consumption of the United States. Solar flares and coronal mass ejections give off radiation that includes X-rays and ultraviolet rays, and charged particles called protons and electrons. This sudden surge in radiation has dramatic effects on Earth. For example, in 1989, the Quebec province in Canada suffered a blackout because many transformers were destroyed by a large magnetic storm near Earth. The magnetic storm, caused by solar activity including solar flares, resulted in millions of dollars in damages. One of the most spectacular features of the Sun are solar prominences (Figure 5). They appear to stream, loop, and arch away from the Sun. The most recognizable prominences appear Page 2 of 8

3 Figure 4. Solar Flare. A solar flare is a highly concentrated explosive release of energy within the solar atmosphere that occurs near sunspots. Flares emit enormous amounts of energy. as huge arching columns of gas above the limb (edge) of the Sun. However, when prominences are photographed on the surface of the Sun, they appear as long, dark, threadlike objects and are called filaments. Like sunspots, prominences are cooler (about 10,000 C) in relation to the much hotter background of the Sun s outer atmosphere (about 1,500,000 C). While solar flares may last hours, prominences can remain for days or even weeks. If you have seen photographs of a solar eclipse, then you have probably noticed a bright halo around the Sun, called the corona (Figure 6). The Sun s corona changes with sunspot activity. When there are more sunspots, the corona appears to be held closely to the Sun; when there are fewer sunspots, the corona streams out into space in a shape that resembles the spike on a warlike, peaked helmet. Sometimes parts of the corona appear to be missing. Logically, we call this a coronal hole. Scientists believe that the solar wind, a million mile per hour gale that blows away from the Sun, originates in coronal holes. Unlike wind on Earth, the solar wind is a stream of ionized (electrically charged) particles speeding away from the Sun (Figure 7). Figure 5. Extreme Ultraviolet. This extreme ultraviolet image of the Sun shows the chromosphere, which is a thin region of the Sun just above the photosphere. A giant prominence can also be seen. Page 3 of 8

4 Figure 6. Solar Eclipse. A solar eclipse shows the ethereal corona the crown of light that surrounds the Sun. Prominences can also be seen as small white blotches in the photograph. Just as the Sun disappears behind the Moon during a total solar eclipse (Figure 6), a flash of bright red light appears. This colorful layer of the Sun, called the chromosphere, becomes visible for a brief instant. Although we know little about the chromosphere, there are curious, permanent features of the chromosphere, called spicules, that we can study in more detail. There are so many of these fine, bright, hairlike features, that they are always visible near the Sun s edge, even though an individual spicule lasts only minutes. Like sunspots, spicules rise vertically above the Sun s surface. Also visible for only minutes, are granulations in the Sun s photosphere. Granulations are rising and falling columns of hot gases that look like fluffy marshmallows arranged in a honeycomb pattern. The tops of these granules form the Sun s surface. Although we refer to the Sun s surface as the photosphere, you probably know that the Sun has no solid surface, unlike Earth. It is an uneven sphere of hot, glowing gas. II. THE PHOTOSPHERE Figure 7. Artist s rendition of the solar wind bombarding Earth s magnetic field with supercharged particles. The photosphere is the visible surface of the Sun that we are most familiar with. Since the Sun is a ball of gas, this is not a solid surface but is actually a layer about 100 km thick (very, very, thin Page 4 of 8

5 compared to the 700,000 km radius of the Sun). When we look at the center of the disk of the Sun we look straight in and see somewhat hotter and brighter regions. When we look at the limb, or edge, of the solar disk we see light that has taken a slanting path through this layer and we only see through the upper, cooler and dimmer regions. This explains the limb darkening that appears as a darkening of the solar disk near the limb (Figure 8). A number of features can be observed in the photosphere with a simple telescope (along with a good filter to reduce the intensity of sunlight to safely observable levels). These features include the dark sunspots, the bright faculae, and granules. We can also measure the flow of material in the photosphere using the Doppler effect. These measurements reveal additional Figure 8. Example of limb darkening. features such as supergranules as well as large-scale flows and a pattern of waves and oscillations. The Sun rotates on its axis once in about 27 days. This rotation was first detected by observing the motion of sunspots in the photosphere. The Sun s rotation axis is tilted by about 7.25 degrees from the axis of the Earth s orbit so we see more of the Sun s north pole in September of each year and more of its south pole in March. Since the Sun is a ball of gas it does not have to rotate rigidly like the solid planets and moons do. In fact, the Sun s equatorial regions rotate faster (taking about 24 days) than the polar regions (which rotate once in more than 30 days). The source of this differential rotation is an area of current research in solar astronomy. III. FEATURES OF THE SUN S INTERIOR We won t study about the Sun s interior here. We just want you to be familiar with the three basic components of the solar interior (see Figure 1). The core is the central part of the Sun where hydrogen fuses into helium to give off energy. This is effectively a nuclear power plant. Energy from the Sun s core then travels outward through what we call the radiation zone. In the convection zone, the hotter gases rise and fall as they are heated from the radiation zone below much like a boiling pot of water. IV. WHAT IS THE SOLAR CYCLE? Every 11 years the Sun undergoes a period of activity called the solar maximum, followed by a period of quiet called the solar minimum. During the solar maximum there are many sunspots, solar flares, and coronal mass ejections, all of which can affect communications and weather here on Earth. One way we track solar activity is by observing sunspots. Sunspots are relatively cool, dark areas that appear as dark blemishes on the face of the Sun and usually travel in pairs. The Figure 8. Sunspot Numbers. Page 5 of 8

6 innermost and darker center is call the umbra whereas the lighter shadow around the edges is called en penumbra of a sunspot. Current theory says that sunspots are caused by horseshoe shaped magnetic fields buried just below the Sun s surface that prevent the flow of hot gases from below. Like a magnet, sunspots have both magnetic north and south poles. The spot where the magnetic field is located cools slightly compared to its surroundings. Because the spot is cooler, it looks darker. The twisted magnetic fields above sunspots are sites where solar flares are observed to occur, and we are now beginning to understand the connection between solar flares and sunspots. During solar maximum there are many sunspots, and during solar minimum there are few. Figure 8 shows the number of sunspots observed during the last two solar cycles. We are just now coming down from the last solar maximum (fall 2000 early 2001). V. SOLAR MAGNETIC FIELDS Magnetism is the key to understanding the Sun. A magnetic field is produced on the Sun by the flow of electrically charged ions and electrons. Sunspots are places where very intense magnetic lines of force break through the Sun s surface. The sunspot cycle results from the recycling of magnetic fields by the flow of material in the interior. The prominences seen floating above the surface of the Sun are supported, and threaded through, with magnetic fields. The streamers and loops seen in the corona are shaped by magnetic fields. Magnetic fields are at the root of virtually all of the features we see on and above the Sun. Without magnetic fields the Sun would be a rather boring star. VI. PREDICTING SPACE WEATHER A better understanding of the Sun s magnetic field and its behavior will allow us to make better predictions of space weather. Observations of magnetic fields associated with solar flares show that flares are likely to occur when the magnetic field lines linking two sunspots become sheared or twisted. Observations of the Sun s magnetic field over the last 20 years illustrate its behavior over two sunspot cycles (Figure 8). However, predicting long-range behavior, such as the size of the sunspot cycle, is still based on observing trends and patterns. We hope that in the near future we will understand the Sun well enough to make these predictions based on current conditions and past history using a mathematical model of the actual processes. ANSWER THE FOLLOWING QUESTIONS IN YOUR LAB NOTEBOOK. 1. Why do we regard the photosphere as the surface of the sun? 2. Explain limb darkening. 3. What is the difference between space weather and weather here on Earth? 4. What is a sunspot and why do they occur? 5. Using Figure 9, what is the average time between solar maximum and solar minimum? 6. Predict the years for the next two sunspot maxima and minima (cycles 24 and 25). 7. Is the solar cycle a constant or periodic function? How do you know? 8. Why is it important to collect and study data over a long period of time before drawing conclusions? Give an example other than sunspot data. 9. Why is sunspot variation important to us? Page 6 of 8

7 Figure 9. Sunspots since circa Page 7 of 8

8 VII. THE EXERCISE: ROTATION OF THE SUN We know from personal experience that Earth rotates because we experience day and night. What about our Sun, that sphere of glowing gas rising just beyond the eastern horizon? Does it rotate? To find out, we can use one of the Sun s most prominent features, its sunspots. Sunspots occur in 11 year cycles where the number of visible spots increases from a minimum of almost zero to a maximum of over 100 spots. After one 11 year cycle, the poles of the horseshoe shaped magnetic fields switch and another cycle begins. Consequently, we have an overall 22 year magnetic cycle as well as an 11 year sunspot cycle. At the beginning of an 11 year cycle, several sunspots appear at about 30 north and south latitudes. As the cycle progresses, you can track the sunspots motion. Generally, individual sunspots or groups of sunspots do you shift significantly in latitude over time; therefore, we conclude that any change in longitude is due to the movement of the Sun itself. The Sun must be rotating. Gather your solar images that you downloaded from the SOHO website. You will be measuring the positions of sunspots from the images and keeping track of this information over the time covered by the dataset. Your instructor will show you how to make these measurements and may provide templates to speed up the process. You may find it helpful to first determine a drift line for a particular sunspot or group of sunspots. You should determine the number of degrees in longitude that the sunspots travel per day. Use this information to calculate the average rotational period of the Sun in days. Record your measurements and calculations in a coherent fashion (tables are nice!!) in your lab notebook. Do not forget the units. ANSWER THE FOLLOWING QUESTIONS IN YOUR LAB NOTEBOOK. 10. Since the sunspot group appears to move across the Sun s surface, what kind of solar motion does this suggest (i.e. orbital, rotation, radial, etc.)? 11. Based on your calculations, what is the average rotational period of the Sun? Do you find any evidence that different parts of the Sun rotate at different rates? Justify your answer. 12. What is your calculated tilt of the Sun s equatorial axis? 13. How do your answers to Questions 11 and 12 compare to the known rotation period and tilt angle of the Sun? 14. If the sunspot group had changed latitude, would you have been able to calculate the number of degrees of change per day as easily? Why or why not? 15. At which solar latitudes do most of the spots occur? 16. Were all the same sunspots detected in all the observations? Why or why not? 17. Do you believe the Sun is a static, solid body? Why or why not? 18. Explain how to use Jupiter s Great Red Spot to determine its period of rotation. VIII. REFERENCES Duckett, K.E. & Moore, M.A. A Laboratory Textbook for Introductory Astronomy, 2 nd Edition, Contemporary Publishing Company, 1986 Hemenway, M.K. & Robbins, R.R. Modern Astronomy: An Activities Approach, Revised Edition, University of Texas Press, Space Science Institute. Solarscapes: Sunspots and Radiation, Page 8 of 8

The Sun as Our Star. Properties of the Sun. Solar Composition. Last class we talked about how the Sun compares to other stars in the sky

The Sun as Our Star. Properties of the Sun. Solar Composition. Last class we talked about how the Sun compares to other stars in the sky The Sun as Our Star Last class we talked about how the Sun compares to other stars in the sky Today's lecture will concentrate on the different layers of the Sun's interior and its atmosphere We will also

More information

Learning Objectives. wavelengths of light do we use to see each of them? mass ejections? Which are the most violent?

Learning Objectives. wavelengths of light do we use to see each of them? mass ejections? Which are the most violent? Our Beacon: The Sun Learning Objectives! What are the outer layers of the Sun, in order? What wavelengths of light do we use to see each of them?! Why does limb darkening tell us the inner Sun is hotter?!

More information

Astronomy 154 Lab 4: The Sun. NASA Image comparing the Earth with the Sun. Image from:

Astronomy 154 Lab 4: The Sun. NASA Image comparing the Earth with the Sun. Image from: Astronomy 154 Lab 3: The Sun NASA Image comparing the Earth with the Sun. Image from: http://www.universetoday.com/16338/the-sun/ The Sun at the center of our Solar System is a massive ball of Hydrogen,

More information

Outline. Astronomy: The Big Picture. Earth Sun comparison. Nighttime observing is over, but a makeup observing session may be scheduled. Stay tuned.

Outline. Astronomy: The Big Picture. Earth Sun comparison. Nighttime observing is over, but a makeup observing session may be scheduled. Stay tuned. Nighttime observing is over, but a makeup observing session may be scheduled. Stay tuned. Next homework due Oct 24 th. I will not be here on Wednesday, but Paul Ricker will present the lecture! My Tuesday

More information

Our sun is the star in our solar system, which lies within a galaxy (Milky Way) within the universe. A star is a large glowing ball of gas that

Our sun is the star in our solar system, which lies within a galaxy (Milky Way) within the universe. A star is a large glowing ball of gas that Our sun is the star in our solar system, which lies within a galaxy (Milky Way) within the universe. A star is a large glowing ball of gas that generates energy through nuclear fusion in its core. The

More information

The Sun. The Sun Is Just a Normal Star 11/5/2018. Phys1411 Introductory Astronomy. Topics. Star Party

The Sun. The Sun Is Just a Normal Star 11/5/2018. Phys1411 Introductory Astronomy. Topics. Star Party Foundations of Astronomy 13e Seeds Phys1411 Introductory Astronomy Instructor: Dr. Goderya Chapter 8 The Sun Star Party This Friday November 9 weather permitting. See the flyer for updates in case of cancellations

More information

Phys 100 Astronomy (Dr. Ilias Fernini) Review Questions for Chapter 8

Phys 100 Astronomy (Dr. Ilias Fernini) Review Questions for Chapter 8 Phys 100 Astronomy (Dr. Ilias Fernini) Review Questions for Chapter 8 MULTIPLE CHOICE 1. Granulation is caused by a. sunspots. * b. rising gas below the photosphere. c. shock waves in the corona. d. the

More information

The Sun ASTR /17/2014

The Sun ASTR /17/2014 The Sun ASTR 101 11/17/2014 1 Radius: 700,000 km (110 R ) Mass: 2.0 10 30 kg (330,000 M ) Density: 1400 kg/m 3 Rotation: Differential, about 25 days at equator, 30 days at poles. Surface temperature: 5800

More information

The Sun. 1a. The Photosphere. A. The Solar Atmosphere. 1b. Limb Darkening. A. Solar Atmosphere. B. Phenomena (Sunspots) C.

The Sun. 1a. The Photosphere. A. The Solar Atmosphere. 1b. Limb Darkening. A. Solar Atmosphere. B. Phenomena (Sunspots) C. The Sun 1 The Sun A. Solar Atmosphere 2 B. Phenomena (Sunspots) Dr. Bill Pezzaglia C. Interior Updated 2014Feb08 A. The Solar Atmosphere 1. Photosphere 2. Chromosphere 3. Corona 4. Solar Wind & earthly

More information

Astronomy Ch 16 The Sun. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

Astronomy Ch 16 The Sun. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Name: Period: Date: Astronomy Ch 16 The Sun MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The light we see from the Sun comes from which layer?

More information

The Sun. 1a. The Photosphere. A. The Solar Atmosphere. 1b. Limb Darkening. A. Solar Atmosphere. B. Phenomena (Sunspots) C.

The Sun. 1a. The Photosphere. A. The Solar Atmosphere. 1b. Limb Darkening. A. Solar Atmosphere. B. Phenomena (Sunspots) C. The Sun 1 The Sun A. Solar Atmosphere 2 B. Phenomena (Sunspots) Dr. Bill Pezzaglia C. Interior Updated 2006Sep18 A. The Solar Atmosphere 1. Photosphere 2. Chromosphere 3. Corona 4. Solar Wind 3 1a. The

More information

Chapter 8 The Sun Our Star

Chapter 8 The Sun Our Star Note that the following lectures include animations and PowerPoint effects such as fly ins and transitions that require you to be in PowerPoint's Slide Show mode (presentation mode). Chapter 8 The Sun

More information

The Sun sends the Earth:

The Sun sends the Earth: The Sun sends the Earth: Solar Radiation - peak wavelength.visible light - Travels at the speed of light..takes 8 minutes to reach Earth Solar Wind, Solar flares, and Coronal Mass Ejections of Plasma (ionized

More information

Radiation Zone. AST 100 General Astronomy: Stars & Galaxies. 5. What s inside the Sun? From the Center Outwards. Meanderings of outbound photons

Radiation Zone. AST 100 General Astronomy: Stars & Galaxies. 5. What s inside the Sun? From the Center Outwards. Meanderings of outbound photons AST 100 General Astronomy: Stars & Galaxies 5. What s inside the Sun? From the Center Outwards Core: Hydrogen ANNOUNCEMENTS Midterm I on Tue, Sept. 29 it will cover class material up to today (included)

More information

Correction to Homework

Correction to Homework Today: Chapter 10 Reading Next Week: Homework Due March 12 Midterm Exam: March 19 Correction to Homework #1: Diameter of eye: 2.5 cm #10: See Ch. 11 Office Hours Monday. 11AM -2 PM Help Sessions Available:

More information

Guidepost. Chapter 08 The Sun 10/12/2015. General Properties. The Photosphere. Granulation. Energy Transport in the Photosphere.

Guidepost. Chapter 08 The Sun 10/12/2015. General Properties. The Photosphere. Granulation. Energy Transport in the Photosphere. Guidepost The Sun is the source of light an warmth in our solar system, so it is a natural object to human curiosity. It is also the star most easily visible from Earth, and therefore the most studied.

More information

PTYS/ASTR 206. The Sun 3/1/07

PTYS/ASTR 206. The Sun 3/1/07 The Announcements Reading Assignment Review and finish reading Chapter 18 Optional reading March 2006 Scientific American: article by Gene Parker titled Shielding Space Travelers http://en.wikipedia.org/wiki/solar_variability

More information

Chapter 23. Light, Astronomical Observations, and the Sun

Chapter 23. Light, Astronomical Observations, and the Sun Chapter 23 Light, Astronomical Observations, and the Sun The study of light Electromagnetic radiation Visible light is only one small part of an array of energy Electromagnetic radiation includes Gamma

More information

The Sun. Never look directly at the Sun, especially NOT through an unfiltered telescope!!

The Sun. Never look directly at the Sun, especially NOT through an unfiltered telescope!! The Sun Introduction We will meet in class for a brief discussion and review of background material. We will then go outside for approximately 1 hour of telescope observing. The telescopes will already

More information

Chapter 9 The Sun. Nuclear fusion: Combining of light nuclei into heavier ones Example: In the Sun is conversion of H into He

Chapter 9 The Sun. Nuclear fusion: Combining of light nuclei into heavier ones Example: In the Sun is conversion of H into He Our sole source of light and heat in the solar system A common star: a glowing ball of plasma held together by its own gravity and powered by nuclear fusion at its center. Nuclear fusion: Combining of

More information

B B E D B E D A C A D D C

B B E D B E D A C A D D C B B A C E E E E C E D E B B A D B E E A E E B C C A B B E D B E D A C A D D C E D Assigned Reading Read Chapters 8.1 and 8.2 Colonel Cady Coleman, Astronaut: Lessons from Space Lead Straight Back to Earth,

More information

The General Properties of the Sun

The General Properties of the Sun Notes: The General Properties of the Sun The sun is an average star with average brightness. It only looks bright because it s so close. It contains 99% of the mass of the solar system. It is made of entirely

More information

Chapter 24: Studying the Sun. 24.3: The Sun Textbook pages

Chapter 24: Studying the Sun. 24.3: The Sun Textbook pages Chapter 24: Studying the Sun 24.3: The Sun Textbook pages 684-690 The sun is one of the 100 billion stars of the Milky Way galaxy. The sun has no characteristics to make it unique to the universe. It is

More information

The Sun Our Extraordinary Ordinary Star

The Sun Our Extraordinary Ordinary Star The Sun Our Extraordinary Ordinary Star 1 Guiding Questions 1. What is the source of the Sun s energy? 2. What is the internal structure of the Sun? 3. How can astronomers measure the properties of the

More information

An Overview of the Details

An Overview of the Details The Sun Our Extraordinary Ordinary Star 1 Guiding Questions 1. What is the source of the Sun s energy? 2. What is the internal structure of the Sun? 3. How can astronomers measure the properties of the

More information

Chapter 10 Our Star. X-ray. visible

Chapter 10 Our Star. X-ray. visible Chapter 10 Our Star X-ray visible Radius: 6.9 10 8 m (109 times Earth) Mass: 2 10 30 kg (300,000 Earths) Luminosity: 3.8 10 26 watts (more than our entire world uses in 1 year!) Why does the Sun shine?

More information

The Sun: Our Star. The Sun is an ordinary star and shines the same way other stars do.

The Sun: Our Star. The Sun is an ordinary star and shines the same way other stars do. The Sun: Our Star The Sun is an ordinary star and shines the same way other stars do. Announcements q Homework # 4 is due today! q Units 49 and 51 Assigned Reading Today s Goals q Today we start section

More information

How the Sun Works. Presented by the

How the Sun Works. Presented by the How the Sun Works Presented by the The Sun warms our planet every day, provides the light by which we see and is absolutely necessary for life on Earth. In this presentation, we will examine the fascinating

More information

Student Instruction Sheet: Unit 4 Lesson 3. Sun

Student Instruction Sheet: Unit 4 Lesson 3. Sun Student Instruction Sheet: Unit 4 Lesson 3 Suggested time: 1.25 Hours What s important in this lesson: Sun demonstrate an understanding of the structure, and nature of our solar system investigate the

More information

The Sun. Chapter 12. Properties of the Sun. Properties of the Sun. The Structure of the Sun. Properties of the Sun.

The Sun. Chapter 12. Properties of the Sun. Properties of the Sun. The Structure of the Sun. Properties of the Sun. Chapter 12 The Sun, Our Star 1 With a radius 100 and a mass of 300,000 that of Earth, the Sun must expend a large amount of energy to withstand its own gravitational desire to collapse To understand this

More information

The Sun: Our Star. A glowing ball of gas held together by its own gravity and powered by nuclear fusion

The Sun: Our Star. A glowing ball of gas held together by its own gravity and powered by nuclear fusion Our Star, the Sun The Sun: Our Star A glowing ball of gas held together by its own gravity and powered by nuclear fusion Radius: 700,000 km (435,000 miles) Diameter: 1.392 million km (865,000 miles) Circumference:

More information

Astronomy 1 Winter 2011

Astronomy 1 Winter 2011 Astronomy 1 Winter 2011 Lecture 19; February 23 2011 Asteroids Comets Meteors Previously on Astro-1 Homework Due 03/02/11 On your own: answer all the review questions in chapters 16 17 and 18 To TAs: answer

More information

The Sun Our Star. Properties Interior Atmosphere Photosphere Chromosphere Corona Magnetism Sunspots Solar Cycles Active Sun

The Sun Our Star. Properties Interior Atmosphere Photosphere Chromosphere Corona Magnetism Sunspots Solar Cycles Active Sun The Sun Our Star Properties Interior Atmosphere Photosphere Chromosphere Corona Magnetism Sunspots Solar Cycles Active Sun General Properties Not a large star, but larger than most Spectral type G2 It

More information

19 The Sun Introduction. Name: Date:

19 The Sun Introduction. Name: Date: Name: Date: 19 The Sun 19.1 Introduction The Sun is a very important object for all life on Earth. The nuclear reactions that occur in its core produce the energy required by plants and animals for survival.

More information

An Overview of the Details

An Overview of the Details Guiding Questions The Sun Our Extraordinary Ordinary Star 1. What is the source of the Sun s energy? 2. What is the internal structure of the Sun? 3. How can astronomers measure the properties of the Sun

More information

The Project. National Schools Observatory

The Project. National Schools Observatory Sunspots The Project This project is devised to give students a good understanding of the structure and magnetic field of the Sun and how this effects solar activity. Students will work with sunspot data

More information

Module 4: Astronomy - The Solar System Topic 2 Content: Solar Activity Presentation Notes

Module 4: Astronomy - The Solar System Topic 2 Content: Solar Activity Presentation Notes The Sun, the largest body in the Solar System, is a giant ball of gas held together by gravity. The Sun is constantly undergoing the nuclear process of fusion and creating a tremendous amount of light

More information

Astronomy 210. Outline. Nuclear Reactions in the Sun. Neutrinos. Solar Observing due April 15 th HW 8 due on Friday.

Astronomy 210. Outline. Nuclear Reactions in the Sun. Neutrinos. Solar Observing due April 15 th HW 8 due on Friday. Astronomy 210 Outline This Class (Lecture 30): Solar Neutrinos Next Class: Stars: Physical Properties Solar Observing due April 15 th HW 8 due on Friday. The Sun Our closest star The Outer Layers of the

More information

HELIOSTAT III - THE SOLAR CHROMOSPHERE

HELIOSTAT III - THE SOLAR CHROMOSPHERE HELIOSTAT III - THE SOLAR CHROMOSPHERE SYNOPSIS: In this lab you will observe, identify, and sketch features that appear in the solar chromosphere. With luck, you may have the opportunity to watch a solar

More information

Directed Reading. Section: Solar Activity SUNSPOTS. Skills Worksheet. 1. How do the gases that make up the sun s interior and atmosphere behave?

Directed Reading. Section: Solar Activity SUNSPOTS. Skills Worksheet. 1. How do the gases that make up the sun s interior and atmosphere behave? Skills Worksheet Directed Reading Section: Solar Activity 1. How do the gases that make up the sun s interior and atmosphere behave? 2. What causes the continuous rising and sinking of the sun s gases?

More information

1-4-1A. Sun Structure

1-4-1A. Sun Structure Sun Structure A cross section of the Sun reveals its various layers. The Core is the hottest part of the internal sun and is the location of nuclear fusion. The heat and energy produced in the core is

More information

Our Star: The Sun. Layers that make up the Sun. Understand the Solar cycle. Understand the process by which energy is generated by the Sun.

Our Star: The Sun. Layers that make up the Sun. Understand the Solar cycle. Understand the process by which energy is generated by the Sun. Goals: Our Star: The Sun Layers that make up the Sun. Understand the Solar cycle. Understand the process by which energy is generated by the Sun. Components of the Sun Solar Interior: Core: where energy

More information

Solar Dynamics Affecting Skywave Communications

Solar Dynamics Affecting Skywave Communications Solar Dynamics Affecting Skywave Communications Ken Larson KJ6RZ October 2010 1 Page Subject 3 1.0 Introduction 3 2.0 Structure of the Sun 3 2.1 Core 3 2.2 Radiation Zone 4 2.3 Convection Zone 4 2.4 Photosphere

More information

Astronomy 1 Fall Reminder: When/where does your observing session meet? [See from your TA.]

Astronomy 1 Fall Reminder: When/where does your observing session meet? [See  from your TA.] Astronomy 1 Fall 2016 Reminder: When/where does your observing session meet? [See email from your TA.] Lecture 9, October 25, 2016 Previously on Astro-1 What is the Moon made of? How did the Moon form?

More information

Lesson 3 THE SOLAR SYSTEM

Lesson 3 THE SOLAR SYSTEM Lesson 3 THE SOLAR SYSTEM THE NATURE OF THE SUN At the center of our solar system is the Sun which is a typical medium sized star. Composed mainly of Hydrogen (73% by mass), 23% helium and the rest is

More information

Facts About The Sun. The Sun is a star found at the of the Solar System. It makes up around % of the Solar System s mass.

Facts About The Sun. The Sun is a star found at the of the Solar System. It makes up around % of the Solar System s mass. Facts About is a star found at the of the Solar System. It makes up around % of the Solar System s mass. At around 1,392,000 kilometres (865,000 miles) wide, the Sun s is about 110 times wider than Earth

More information

The Sun. The Sun is a star: a shining ball of gas powered by nuclear fusion. Mass of Sun = 2 x g = 330,000 M Earth = 1 M Sun

The Sun. The Sun is a star: a shining ball of gas powered by nuclear fusion. Mass of Sun = 2 x g = 330,000 M Earth = 1 M Sun The Sun The Sun is a star: a shining ball of gas powered by nuclear fusion. Mass of Sun = 2 x 10 33 g = 330,000 M Earth = 1 M Sun Radius of Sun = 7 x 10 5 km = 109 R Earth = 1 R Sun Luminosity of Sun =

More information

THE SUN AND THE SOLAR SYSTEM

THE SUN AND THE SOLAR SYSTEM Chapter 26 THE SUN AND THE SOLAR SYSTEM CHAPTER 26 SECTION 26.1: THE SUN S SIZE, HEAT, AND STRUCTURE Objectives: What is the Sun s structure and source of energy? Key Vocabulary: Fusion Photosphere Corona

More information

Explain how the sun converts matter into energy in its core. Describe the three layers of the sun s atmosphere.

Explain how the sun converts matter into energy in its core. Describe the three layers of the sun s atmosphere. Chapter 29 and 30 Explain how the sun converts matter into energy in its core. Describe the three layers of the sun s atmosphere. Explain how sunspots are related to powerful magnetic fields on the sun.

More information

1. Solar Atmosphere Surface Features and Magnetic Fields

1. Solar Atmosphere Surface Features and Magnetic Fields 1. Solar Atmosphere Surface Features and Magnetic Fields Sunspots, Granulation, Filaments and Prominences, Coronal Loops 2. Solar Cycle: Observations The Sun: applying black-body radiation laws Radius

More information

Astronomy 150: Killer Skies. Lecture 18, March 1

Astronomy 150: Killer Skies. Lecture 18, March 1 Assignments: Astronomy 150: Killer Skies HW6 due next Friday at start of class HW5 and Computer Lab 1 due Night Observing continues next week Lecture 18, March 1 Computer Lab 1 due next Friday Guest Lecturer:

More information

Solar Activity The Solar Wind

Solar Activity The Solar Wind Solar Activity The Solar Wind The solar wind is a flow of particles away from the Sun. They pass Earth at speeds from 400 to 500 km/s. This wind sometimes gusts up to 1000 km/s. Leaves Sun at highest speeds

More information

Sun s Properties. Overview: The Sun. Composition of the Sun. Sun s Properties. The outer layers. Photosphere: Surface. Nearest.

Sun s Properties. Overview: The Sun. Composition of the Sun. Sun s Properties. The outer layers. Photosphere: Surface. Nearest. Overview: The Sun Properties of the Sun Sun s outer layers Photosphere Chromosphere Corona Solar Activity Sunspots & the sunspot cycle Flares, prominences, CMEs, aurora Sun s Interior The Sun as an energy

More information

Summer 2013 Astronomy - Test 3 Test form A. Name

Summer 2013 Astronomy - Test 3 Test form A. Name Summer 2013 Astronomy - Test 3 Test form A Name Do not forget to write your name and fill in the bubbles with your student number, and fill in test form A on the answer sheet. Write your name above as

More information

The Quiet Sun The sun is currently being studied by several spacecraft Ulysses, SOHO, STEREO, and ACE.

The Quiet Sun The sun is currently being studied by several spacecraft Ulysses, SOHO, STEREO, and ACE. The Quiet Sun The sun is currently being studied by several spacecraft Ulysses, SOHO, STEREO, and ACE. Messenger also contains instruments that can do some solar studies. http://www.stereo.gsfc.nasa.gov

More information

Helios in Greek and Sol in Roman

Helios in Greek and Sol in Roman Helios in Greek and Sol in Roman Drove his chariot across the sky to provide daylight Returned each night in a huge golden cup on the river Oceanus His son Phaeton drove the chariot one day but lost control

More information

Prentice Hall EARTH SCIENCE

Prentice Hall EARTH SCIENCE Prentice Hall EARTH SCIENCE Tarbuck Lutgens Chapter 24 Studying the Sun 24.1 The Study of Light Electromagnetic Radiation Electromagnetic radiation includes gamma rays, X-rays, ultraviolet light, visible

More information

The Structure of the Sun. CESAR s Booklet

The Structure of the Sun. CESAR s Booklet How stars work In order to have a stable star, the energy it emits must be the same as it can produce. There must be an equilibrium. The main source of energy of a star it is nuclear fusion, especially

More information

Our sole source of light and heat in the solar system. A very common star: a glowing g ball of gas held together by its own gravity and powered

Our sole source of light and heat in the solar system. A very common star: a glowing g ball of gas held together by its own gravity and powered The Sun Visible Image of the Sun Our sole source of light and heat in the solar system A very common star: a glowing g ball of gas held together by its own gravity and powered by nuclear fusion at its

More information

Chapter 23. Our Solar System

Chapter 23. Our Solar System Chapter 23 Our Solar System Our Solar System 1 Historical Astronomy Wandering Stars Greeks watched the stars move across the sky and noticed five stars that wandered around and did not follow the paths

More information

Astronomy Chapter 12 Review

Astronomy Chapter 12 Review Astronomy Chapter 12 Review Approximately how massive is the Sun as compared to the Earth? A. 100 times B. 300 times C. 3000 times D. 300,000 times E. One million times Approximately how massive is the

More information

The Magnetic Sun. CESAR s Booklet

The Magnetic Sun. CESAR s Booklet The Magnetic Sun CESAR s Booklet 1 Introduction to planetary magnetospheres and the interplanetary medium Most of the planets in our Solar system are enclosed by huge magnetic structures, named magnetospheres

More information

CONTENT EXPECTATIONS

CONTENT EXPECTATIONS THE SUN & THE STARS CONTENT EXPECTATIONS STARS What are stars? Are they all the same? What makes them different? What is our nearest star? THE SUN Why is it important? provides heat and light that we need

More information

The Sun s Dynamic Atmosphere

The Sun s Dynamic Atmosphere Lecture 16 The Sun s Dynamic Atmosphere Jiong Qiu, MSU Physics Department Guiding Questions 1. What is the temperature and density structure of the Sun s atmosphere? Does the atmosphere cool off farther

More information

Chapter Introduction Lesson 1 The View from Earth Lesson 2 The Sun and Other Stars Lesson 3 Evolution of Stars Lesson 4 Galaxies and the Universe

Chapter Introduction Lesson 1 The View from Earth Lesson 2 The Sun and Other Stars Lesson 3 Evolution of Stars Lesson 4 Galaxies and the Universe Chapter Introduction Lesson 1 The View from Earth Lesson 2 The Sun and Other Stars Lesson 3 Evolution of Stars Lesson 4 Galaxies and the Universe Chapter Wrap-Up What makes up the universe and how does

More information

9-1 The Sun s energy is generated by thermonuclear reactions in its core The Sun s luminosity is the amount of energy emitted each second and is

9-1 The Sun s energy is generated by thermonuclear reactions in its core The Sun s luminosity is the amount of energy emitted each second and is 1 9-1 The Sun s energy is generated by thermonuclear reactions in its core The Sun s luminosity is the amount of energy emitted each second and is produced by the proton-proton chain in which four hydrogen

More information

ASTRONOMY. Chapter 15 THE SUN: A GARDEN-VARIETY STAR PowerPoint Image Slideshow

ASTRONOMY. Chapter 15 THE SUN: A GARDEN-VARIETY STAR PowerPoint Image Slideshow ASTRONOMY Chapter 15 THE SUN: A GARDEN-VARIETY STAR PowerPoint Image Slideshow FIGURE 15.1 Our Star. The Sun our local star is quite average in many ways. However, that does not stop it from being a fascinating

More information

Stars and Galaxies. The Sun and Other Stars

Stars and Galaxies. The Sun and Other Stars CHAPTER 22 Stars and Galaxies LESSON 2 The Sun and Other Stars What do you think? Read the two statements below and decide whether you agree or disagree with them. Place an A in the Before column if you

More information

Name Date Per Teacher. Packet #4 The Sun

Name Date Per Teacher. Packet #4 The Sun Packet #4 The Sun Reading Guide: Chapter 29.1 (read text pages 755 760) STRUCTURE OF THE SUN 1e Students know the Sun is a typical star and is powered by nuclear reactions, primarily the fusion of hydrogen

More information

CHAPTER 29: STARS BELL RINGER:

CHAPTER 29: STARS BELL RINGER: CHAPTER 29: STARS BELL RINGER: Where does the energy of the Sun come from? Compare the size of the Sun to the size of Earth. 1 CHAPTER 29.1: THE SUN What are the properties of the Sun? What are the layers

More information

Properties of Stars. Characteristics of Stars

Properties of Stars. Characteristics of Stars Properties of Stars Characteristics of Stars A constellation is an apparent group of stars originally named for mythical characters. The sky contains 88 constellations. Star Color and Temperature Color

More information

The Sun. Basic Properties. Radius: Mass: Luminosity: Effective Temperature:

The Sun. Basic Properties. Radius: Mass: Luminosity: Effective Temperature: The Sun Basic Properties Radius: Mass: 5 R Sun = 6.96 km 9 R M Sun 5 30 = 1.99 kg 3.33 M ρ Sun = 1.41g cm 3 Luminosity: L Sun = 3.86 26 W Effective Temperature: L Sun 2 4 = 4πRSunσTe Te 5770 K The Sun

More information

Announcements. - Homework #5 due today - Review on Monday 3:30 4:15pm in RH103 - Test #2 next Tuesday, Oct 11

Announcements. - Homework #5 due today - Review on Monday 3:30 4:15pm in RH103 - Test #2 next Tuesday, Oct 11 Announcements - Homework #5 due today - Review on Monday 3:30 4:15pm in RH103 - Test #2 next Tuesday, Oct 11 Review for Test #2 Oct 11 Topics: The Solar System and its Formation The Earth and our Moon

More information

CHAPTER 9: STARS AND GALAXIES

CHAPTER 9: STARS AND GALAXIES CHAPTER 9: STARS AND GALAXIES Characteristics of the Sun 1. The Sun is located about 150 million kilometres from the Earth. 2. The Sun is made up of hot gases, mostly hydrogen and helium. 3. The size of

More information

Chapter 3 The Solar System

Chapter 3 The Solar System Name: Date: Period: Chapter 3 The Solar System Section 1 Observing the Solar System (pp. 72-77) Key Concepts What are the geocentric and heliocentric systems? How did Copernicus, Galileo, and Kepler contribute

More information

Lecture 17 The Sun October 31, 2018

Lecture 17 The Sun October 31, 2018 Lecture 17 The Sun October 31, 2018 1 2 Exam 2 Information Bring a #2 pencil! Bring a calculator. No cell phones or tablets allowed! Contents: Free response problems (2 questions, 10 points) True/False

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Homework Ch 7, 8, 9 Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Our most detailed knowledge of Uranus and Neptune comes from 1) A) the

More information

IX. Dwarf Planets A. A planet is defined to be an object that is large enough to coalesce into a sphere and to have cleared its orbit of other

IX. Dwarf Planets A. A planet is defined to be an object that is large enough to coalesce into a sphere and to have cleared its orbit of other 7/1 VII. VIII. Uranus A. Gas Giant 1. Rings but not visible 2. HUGE axial tilt 97! 3. Mostly hydrogen and helium 4. Medium rotation rate 5. Cold 55 K at the cloud tops B. Physical characteristics 1. Mass:

More information

Stars and Galaxies. Content Outline for Teaching

Stars and Galaxies. Content Outline for Teaching Section 1 Stars A. Patterns of stars - constellations 1. Ancient cultures used mythology or everyday items to name constellations 2. Modern astronomy studies 88 constellations 3. Some constellations are

More information

Greeks watched the stars move across the sky and noticed five stars that wandered around and did not follow the paths of the normal stars.

Greeks watched the stars move across the sky and noticed five stars that wandered around and did not follow the paths of the normal stars. Chapter 23 Our Solar System Our Solar System Historical Astronomy Wandering Stars Greeks watched the stars move across the sky and noticed five stars that wandered around and did not follow the paths of

More information

A Closer Look at the Sun

A Closer Look at the Sun Our Star A Closer Look at the Sun Our goals for learning Why was the Sun s energy source a major mystery? Why does the Sun shine? What is the Sun s structure? Why was the Sun s energy source a major mystery?

More information

Chapter 14 Lecture. The Cosmic Perspective Seventh Edition. Our Star Pearson Education, Inc.

Chapter 14 Lecture. The Cosmic Perspective Seventh Edition. Our Star Pearson Education, Inc. Chapter 14 Lecture The Cosmic Perspective Seventh Edition Our Star 14.1 A Closer Look at the Sun Our goals for learning: Why does the Sun shine? What is the Sun's structure? Why does the Sun shine? Is

More information

Chapter 14 Lecture. Chapter 14: Our Star Pearson Education, Inc.

Chapter 14 Lecture. Chapter 14: Our Star Pearson Education, Inc. Chapter 14 Lecture Chapter 14: Our Star 14.1 A Closer Look at the Sun Our goals for learning: Why does the Sun shine? What is the Sun's structure? Why does the Sun shine? Is it on FIRE? Is it on FIRE?

More information

Name: Date: 2. The temperature of the Sun's photosphere is A) close to 1 million K. B) about 10,000 K. C) 5800 K. D) 4300 K.

Name: Date: 2. The temperature of the Sun's photosphere is A) close to 1 million K. B) about 10,000 K. C) 5800 K. D) 4300 K. Name: Date: 1. What is the Sun's photosphere? A) envelope of convective mass motion in the outer interior of the Sun B) lowest layer of the Sun's atmosphere C) middle layer of the Sun's atmosphere D) upper

More information

Planets Inner vs. outer Composition inner planets are rocky/outer are gas Size inner are smaller/outer are much larger Distance from sun inner are

Planets Inner vs. outer Composition inner planets are rocky/outer are gas Size inner are smaller/outer are much larger Distance from sun inner are Planets Inner vs. outer Composition inner planets are rocky/outer are gas Size inner are smaller/outer are much larger Distance from sun inner are close/outer are farther. Earth is 1 AU from the sun Life

More information

Astronomy Exam 3 - Sun and Stars

Astronomy Exam 3 - Sun and Stars Astronomy Exam 3 - Sun and Stars Study online at quizlet.com/_4zgp6 1. `what are the smallest group of stars in the H-R diagram 2. A star has a parallax of 0.05". what is the distance from the earth? white

More information

Stars, Galaxies & the Universe Announcements. Stars, Galaxies & the Universe Observing Highlights. Stars, Galaxies & the Universe Lecture Outline

Stars, Galaxies & the Universe Announcements. Stars, Galaxies & the Universe Observing Highlights. Stars, Galaxies & the Universe Lecture Outline Stars, Galaxies & the Universe Announcements Lab Observing Trip Next week: Tues (9/28) & Thurs (9/30) let me know ASAP if you have an official conflict (class, work) - website: http://astro.physics.uiowa.edu/~clang/sgu_fall10/observing_trip.html

More information

Killer Skies. Homework 5 due Monday Night Observing continuing Last time: White Dwarf Today: Active Sun. Music: Invisible Sun Police

Killer Skies. Homework 5 due Monday Night Observing continuing Last time: White Dwarf Today: Active Sun. Music: Invisible Sun Police Killer Skies Homework 5 due Monday Night Observing continuing Last time: White Dwarf Today: Active Sun Music: Invisible Sun Police 1 Night Observing Night Observing probably last week if you do it, need

More information

Chapter 14 Our Star A Closer Look at the Sun. Why was the Sun s energy source a major mystery?

Chapter 14 Our Star A Closer Look at the Sun. Why was the Sun s energy source a major mystery? Chapter 14 Our Star 14.1 A Closer Look at the Sun Our goals for learning Why was the Sun s energy source a major mystery? Why does the Sun shine? What is the Sun s structure? Why was the Sun s energy source

More information

Weight of upper layers compresses lower layers

Weight of upper layers compresses lower layers Weight of upper layers compresses lower layers Gravitational equilibrium: Energy provided by fusion maintains the pressure Gravitational contraction: Provided energy that heated core as Sun was forming

More information

Stars. The size of the Sun

Stars. The size of the Sun Stars Huge spheres of gas floating in space Composed primarily of H, He. Produce their own energy. Our Galaxy: 10 11 (100 billion) stars. The Sun: a typical star Stars range from ~ 0.1 to ~ 20 M M = solar

More information

Astronomy. Our Star, The Sun

Astronomy. Our Star, The Sun Astronomy A. Dayle Hancock adhancock@wm.edu Small 239 Office hours: MTWR 10-11am Our Star, The Sun The source of the Sun's heat and light Models of the Sun's interior The Sun's vibrations Probing the energy

More information

Hydrogen Lines. What can we learn from light? Spectral Classification. Visible Hydrogen Spectrum Lines: Series. Actual Spectrum from SDSS

Hydrogen Lines. What can we learn from light? Spectral Classification. Visible Hydrogen Spectrum Lines: Series. Actual Spectrum from SDSS What can we learn from light? Hydrogen Lines Temperature Energy Chemical Composition Speed towards or away from us All from the! Lower E, Lower f, λ Visible! Higher E, Higher f, λ Visible Hydrogen Spectrum

More information

10/17/ A Closer Look at the Sun. Chapter 11: Our Star. Why does the Sun shine? Lecture Outline

10/17/ A Closer Look at the Sun. Chapter 11: Our Star. Why does the Sun shine? Lecture Outline Lecture Outline 11.1 A Closer Look at the Sun Chapter 11: Our Star Our goals for learning: Why does the Sun shine? What is the Sun's structure? Why does the Sun shine? Is it on FIRE? Is it on FIRE? Chemical

More information

The point in an orbit around the Sun at which an object is at its greatest distance from the Sun (Opposite of perihelion).

The point in an orbit around the Sun at which an object is at its greatest distance from the Sun (Opposite of perihelion). ASTRONOMY TERMS Albedo Aphelion Apogee A measure of the reflectivity of an object and is expressed as the ratio of the amount of light reflected by an object to that of the amount of light incident upon

More information

8.2 The Sun pg Stars emit electromagnetic radiation, which travels at the speed of light.

8.2 The Sun pg Stars emit electromagnetic radiation, which travels at the speed of light. 8.2 The Sun pg. 309 Key Concepts: 1. Careful observation of the night sky can offer clues about the motion of celestial objects. 2. Celestial objects in the Solar System have unique properties. 3. Some

More information

The Interior Structure of the Sun

The Interior Structure of the Sun The Interior Structure of the Sun Data for one of many model calculations of the Sun center Temperature 1.57 10 7 K Pressure 2.34 10 16 N m -2 Density 1.53 10 5 kg m -3 Hydrogen 0.3397 Helium 0.6405 The

More information

The Sun is the nearest star to Earth, and provides the energy that makes life possible.

The Sun is the nearest star to Earth, and provides the energy that makes life possible. 1 Chapter 8: The Sun The Sun is the nearest star to Earth, and provides the energy that makes life possible. PRIMARY SOURCE OF INFORMATION about the nature of the Universe NEVER look at the Sun directly!!

More information

Convection causes granules. Photosphere isn t actually smooth! Granules Up-Close: like boiling water. Corona or of the Sun. Chromosphere: sphere of

Convection causes granules. Photosphere isn t actually smooth! Granules Up-Close: like boiling water. Corona or of the Sun. Chromosphere: sphere of Overview Properties of the Sun Sun s outer layers Photosphere Chromosphere Corona Solar Activity Sunspots & the sunspot cycle Flares, prominences, CMEs, aurora Sun s Interior The Sun as an energy source

More information

1 A= one Angstrom = 1 10 cm

1 A= one Angstrom = 1 10 cm Our Star : The Sun )Chapter 10) The sun is hot fireball of gas. We observe its outer surface called the photosphere: We determine the temperature of the photosphere by measuring its spectrum: The peak

More information