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

Size: px
Start display at page:

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

Transcription

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

2 General Properties Not a large star, but larger than most Spectral type G2 It appears bright because it is so close Absolute visual magnitude = 4.83 Sun s radius is 109 times Earth s radius (R ʘ = 1.4 x 10 6 km) Sun s mass is 333,000 times Earth s mass (m ʘ = 2 x kg) Consists entirely of ionized gas (av. density = 1.4 g/cm 3 ) Central temperature = 1.5 x 10 7 K Surface temperature = 5800 K

3 Physical Properties of the Sun Interior structure of the Sun: Outer layers are not to scale The core is where nuclear fusion takes place

4 Physical Properties of the Sun Luminosity the total power radiated by a star it can be calculated from the fraction of that energy that reaches Earth. The luminosity of the Sun is about W the equivalent of 10 billion 1-megaton nuclear bombs per second. Solar constant amount of the Sun's energy reaching Earth = 1400 W/m 2. It is the Sun s energy flux (energy/unit area) at 1 AU.

5 Determining Luminosity Measure k, the solar constant, the energy flux reaching the Earth Measure a, the distance from the Earth to the Sun Determine the surface area A of a sphere with the radius a: A = 4π a 2 Luminosity: L = ka

6 The Energy of the Sun Nuclear fusion is the energy producing mechanism of the Sun. In general, nuclear fusion works like this: nucleus 1 + nucleus 2 nucleus 3 + energy But where does the energy come from? It comes from the loss of mass m: if you add up the masses of the initial nuclei, you will find that it is more than the mass of the final nucleus. The difference in mass m has been changed into energy. The relationship between mass and energy is found in Einstein s famous equation: E = m c 2 In this equation, c is the speed of light which is a very large number.

7 Energy Production Nuclear fusion produces energy up to the formation of iron. Nuclear fission produces energy when elements heavier than iron split. Binding energy is a result of the strong force. It has a very short range. It is the strongest of the 4 known forces: electromagnetic, weak, strong, gravitational

8 Basic reaction: Energy Generation in the Sun: 4 1 H 4 He + energy 4 protons have x kg (= 0.7 %) more mass than 4 He Energy gain = Δm c 2 = 0.43 x J per reaction the Sun needs reactions, transforming 5 million tons of mass into energy every second so that its pressure balances its own gravity to keep it from collapsing. The Proton-Proton Chain Need large proton speed ( high temperature) to overcome Coulomb barrier (electromagnetic repulsion between protons). T 10 7 K = 10 million K

9 The Solar Interior The balance between gravitational forces pulling toward the center with the heat pressure pushing out is called hydrostatic equilibrium. A differential equation expressing hydrostatic equilibrium as a function of radius is one of the basic equations used to model stellar interiors.

10 The Solar Interior Doppler shifts of solar spectral lines indicate a complex pattern of standing waves inside the Sun.

11 The Solar Interior These graphs plot solar density and temperature as a function of distance from the Sun s center, according to the standard solar model

12 Heat Transport Heat is transported by 3 physical mechanisms: Conduction Radiation Convection

13 The Solar Interior Energy transport in stars is either by radiation or by convection Interior regions or zones are dominated by one transport mechanism or the other A differential equation expressing energy transport as a function of radius is another of the basic equations used to model stellar interiors. The radiation zone is relatively transparent; the cooler convection zone is opaque

14 The Layers of the Solar Atmosphere Visible Sunspot Regions Ultraviolet Photosphere Corona Chromosphere Coronal activity, seen in visible light

15 The Solar Atmosphere The corona and the chromosphere are only visible during solar eclipses The photosphere is the apparent surface of the Sun Heat Flow Solar interior Temperature increases inward

16 The Solar Atmosphere Spectral analysis can tell us what elements are present. Absorption lines are used for the photosphere and the chromosphere. Emission lines are used for the corona.

17 Spectral lines are formed when light is absorbed before escaping from the Sun; this happens when its energy is close to an atomic transition, so it is absorbed. This absorption spectrum shows absorption lines for some of the elements in the Sun. The Solar Atmosphere

18 The Photosphere Apparent surface layer of the Sun Depth ~500 km Temperature ~5800 K Highly opaque (H - ions) Absorbs and re-emits radiation produced in the solar interior Corona

19 Energy Transport in the Photosphere Energy generated in the Sun s center must be transported outward. In the photosphere, this happens through Cool gas sinking down Convection Bubbles of hot gas rising up ~1000 km Bubbles last for ~10-20 min

20 Granulation is the visible consequence of convection

21 The Chromosphere Region of Sun s atmosphere just above the photosphere. Visible, UV, and X-ray lines from highly ionized gases Temperature increases gradually from ~4500 K to ~10,000 K, then jumps to ~1 x 10 6 K Filaments Transition region from Chromosphere to Corona Chromospheric structures visible in H α emission (filtergram)

22 The Chromosphere Spicules: Spikes of cooler gas from the photosphere, rising up into the chromosphere. Visible in H α emission. Each one lasts ~ 5-15 min.

23 Green River, WY June 8, 1918 As seen during solar eclipses Phillipines March 1988

24 The Solar Wind The solar corona is blown into interplanetary space and is called the solar wind The solar wind Is spiral shaped because of the Sun s rotation Carries the Sun s magnetic field into interplanetary space Interacts with planetary magnetic fields Ionizes gas around comets and forms the comet s ion tail

25 The Sun s Magnetic Cycle 1. The Sun s magnetic field is generated in the convection zone, not in the core 2. The Sun rotates faster at the equator than near the poles. 3. This differential rotation pulls north-south magnetic field lines in the direction of rotation at the equator.

26 The Sun s Magnetic Cycle 4. After 11 years, the magnetic field pattern becomes so complex that the field structure is re-arranged. 5. The new magnetic field structure is similar to the original one, but reversed! Magnetic Field Reversal 6. A new 11-year cycle begins with a reversed magnetic-field orientation

27 Sunspots and Magnetic Fields Magnetic North Poles Ultraviolet filtergram Magnetic image Magnetic fields in sunspots are ~1000 times stronger than average. In sunspots, magnetic field lines emerge out of the photosphere. Magnetic South Poles

28 Sunspots Cooler regions of the photosphere (T 4240 K). Appear dark against the bright Sun. They would still be much brighter than the full Moon when placed on the night sky!

29 Sunspots and Magnetic Loops Sunspots are in pairs of different polarity A magnetic field loops out of the Sun from one spot to the other in the pair The leading spot has the same magnetic polarity as the overall polarity of the hemisphere Magnetic field lines

30 Magnetic Fields in Sunspots Magnetic fields on the photosphere can be measured using the Zeeman effect Sunspots are related to magnetic activity on the photosphere

31 The Solar Cycle 11-year cycle sunspot cycle After 11 years, the North/South order of leading/trailing sunspots is reversed Reversal of magnetic polarity The sunspot cycle starts out with a small number of spots at higher latitudes It evolves to a larger number of sunspots at lower latitudes (towards the equator) as the cycle progresses. Total solar cycle = 22 years The Maunder butterfly diagram

32 The Maunder Minimum The period from ~1645 to 1715 had very few sunspots, which coincides with a period of colder-than-usual winters in Europe. Is there a cause and effect relationship?

33 The Active Sun Areas around sunspots are active Large eruptions may occur in the photosphere. A solar prominence is a large sheet of ejected gas

34 The Active Sun A solar flare is a large explosion on the Sun s surface, emitting a similar amount of energy as a prominence, but in seconds or minutes rather than days or weeks. Solar flares can significantly influence the Earth s magnetic field structure and cause northern lights (aurora borealis).

35 The Active Sun Coronal mass ejection occurs when a large bubble detaches from the Sun and escapes into space

36 The Active Sun The solar wind escapes the Sun mostly through coronal holes, which can be seen in X-ray images

37 The Solar Neutrino Problem The solar interior cannot be observed directly with electromagnetic radiation because it is highly opaque. Neutrinos from fusion reactions can escape the Sun without being absorbed. However, solar neutrino experiments have detected a much lower flux of neutrinos than expected (the solar neutrino problem ). Recent laboratory experiments have shown that neutrinos oscillate between different flavors They oscillate during their passage from the Sun and only one flavor can be detected thereby reducing the flux This solved the solar neutrino problem. Davis solar neutrino experiment

### 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.

### 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

### 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

### 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

### 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

### 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

### 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 =

### 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

### 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

### 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

### 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

### 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

### 10/18/ A Closer Look at the Sun. Chapter 11: Our Star. Why does the Sun shine? Lecture Outline

10/18/17 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

### 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

### 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

### The Sun. How are these quantities measured? Properties of the Sun. Chapter 14

The Sun Chapter 14 The Role of the Sun in the Solar System > 99.9% of the mass Its mass is responsible for the orderly orbits of the planets Its heat is responsible for warming the planets It is the source

### 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:

### 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?

### 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

### 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

### The Sun. October 21, ) H-R diagram 2) Solar Structure 3) Nuclear Fusion 4) Solar Neutrinos 5) Solar Wind/Sunspots

The Sun October 21, 2002 1) H-R diagram 2) Solar Structure 3) Nuclear Fusion 4) Solar Neutrinos 5) Solar Wind/Sunspots Review Blackbody radiation Measuring stars distance luminosity brightness and distance

### The Sun. the main show in the solar system. 99.8% of the mass % of the energy. Homework due next time - will count best 5 of 6

The Sun the main show in the solar system 99.8% of the mass 99.9999...% of the energy 2007 Pearson Education Inc., publishing as Pearson Addison-Wesley Homework due next time - will count best 5 of 6 The

### 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

### 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?

### 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

### 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

### 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

### 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

### Next quiz: Monday, October 24

No homework for Wednesday Read Chapter 8! Next quiz: Monday, October 24 1 Chapter 7 Atoms and Starlight Types of Spectra: Pictorial Some light sources are comprised of all colors (white light). Other light

### 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

### The Sun. The Chromosphere of the Sun. The Surface of the Sun

Key Concepts: Lecture 22: The Sun Basic properties of the Sun The outer layers of the Sun: Chromosphere, Corona Sun spots and solar activity: impact on the Earth Nuclear Fusion: the source of the Sun s

### 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

### 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

### 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

### 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

### 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?

### 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?!

### 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

### 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

### 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

### 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

### 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

### Some Good News. Announcements. Lecture 10 The Sun. How does the Sun shine? The Sun s Energy Source

Announcements Homework due today. Put your homework in the box NOW. Please STAPLE them if you have not done yet. Quiz#3 on Tuesday (Oct 5) Announcement at the end of this lecture. If you could not pick

### 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

### 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:

### 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

### 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

### 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

### 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.

### The Sun 11/6/2018. Phys1411 Introductory Astronomy. Topics we have covered. Topics for Today class. Sun Spots

Foundations of Astronomy 13e Seeds Phys1411 Introductory Astronomy Instructor: Dr. Goderya Chapter 8 The Sun Topics we have covered I. Introduction A. Viewing the Sun B. General Definition C. General Properties

### 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?

### 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

### The Sun. Nearest Star Contains most of the mass of the solar system Source of heat and illumination

The Sun Nearest Star Contains most of the mass of the solar system Source of heat and illumination Outline Properties Structure Solar Cycle Energetics Equation of Stellar Structure TBC Properties of Sun

### Today The Sun. Events

Today The Sun Events Last class! Homework due now - will count best 5 of 6 Final exam Dec. 20 @ 12:00 noon here Review this Course! www.case.edu/utech/course-evaluations/ The Sun the main show in the solar

### Astronomy 1504 Section 002 Astronomy 1514 Section 10 Midterm 2, Version 1 October 19, 2012

Astronomy 1504 Section 002 Astronomy 1514 Section 10 Midterm 2, Version 1 October 19, 2012 Choose the answer that best completes the question. Read each problem carefully and read through all the answers.

### 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?

### 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

### 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

### 4 Layers of the Sun. CORE : center, where fusion occurs

4 Layers of the Sun CORE : center, where fusion occurs RADIATION LAYER: energy transfer by radiation (like energy coming from a light bulb or heat lamp which you can feel across the room) CONVECTION LAYER:

### Chapter 14 Our Star Pearson Education, Inc.

Chapter 14 Our Star Basic Types of Energy Kinetic (motion) Radiative (light) Potential (stored) Energy can change type, but cannot be created or destroyed. Thermal Energy: the collective kinetic energy

### 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

### 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

### 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

### The Sun 11/27/2017. Phys1411 Introductory Astronomy. Exam 3. Topics we have covered. Sun Spots. Topics for Today class

Foundations of Astronomy 13e Seeds Phys1411 Introductory Astronomy Instructor: Dr. Goderya Chapter 8 The Sun Exam 3 Wednesday November 29 th Homework for Chapter 7 and 8 are online on MindTap: Due Wednesday

### 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

### ASTR Midterm 1 Phil Armitage, Bruce Ferguson

ASTR 1120-001 Midterm 1 Phil Armitage, Bruce Ferguson FIRST MID-TERM EXAM FEBRUARY 16 th 2006: Closed books and notes, 1 hour. Please PRINT your name and student ID on the places provided on the scan sheet.

### Astr 1050 Mon. March 30, 2015 This week s Topics

Astr 1050 Mon. March 30, 2015 This week s Topics Chapter 14: The Sun, Our Star Structure of the Sun Physical Properties & Stability Photosphere Opacity Spectral Line Formation Temperature Profile The Chromosphere

### 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

### 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

### 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

### 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?

### 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

### Proton-proton cycle 3 steps PHYS 162 1

Proton-proton cycle 3 steps PHYS 162 1 4 Layers of the Sun CORE : center, where fusion occurs RADIATION: energy transfer by radiation CONVECTION: energy transfer by convection PHOTOSPHERE: what we see

### Lec 7: Classification of Stars, the Sun. What prevents stars from collapsing under the weight of their own gravity? Text

1 Astr 102 Lec 7: Classification of Stars, the Sun What prevents stars from collapsing under the weight of their own gravity? Text Why is the center of the Sun hot? What is the source of the Sun s energy?

### 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

### 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,

### Types of Stars 1/31/14 O B A F G K M. 8-6 Luminosity. 8-7 Stellar Temperatures

Astronomy 113 Dr. Joseph E. Pesce, Ph.D. The Nature of Stars For nearby stars - measure distances with parallax 1 AU d p 8-2 Parallax A January ³ d = 1/p (arcsec) [pc] ³ 1pc when p=1arcsec; 1pc=206,265AU=3

### 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)

### The Sun. SESAME Astronomy Week 4. Thursday, February 10, 2011

The Sun SESAME Astronomy Week 4 1 1 Our star Not special: typical mass, typical temperature, typical size, typical planetary system about halfway through its 10 billion year lifespan 2 2 Vital statistics

### ASTRONOMY 1 EXAM 3 a Name

ASTRONOMY 1 EXAM 3 a Name Identify Terms - Matching (20 @ 1 point each = 20 pts.) Multiple Choice (25 @ 2 points each = 50 pts.) Essays (choose 3 of 4 @ 10 points each = 30 pt 1.Luminosity D 8.White dwarf

### 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

### 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

### 14.1 A Closer Look at the Sun

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? NO! Chemical energy content Luminosity ~

### 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

### 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

### 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!!

### Exam #2 Review Sheet. Part #1 Clicker Questions

Exam #2 Review Sheet Part #1 Clicker Questions 1) The energy of a photon emitted by thermonuclear processes in the core of the Sun takes thousands or even millions of years to emerge from the surface because

### 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

### 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

### Earth/Space/Physics Kristy Halteman.

Earth/Space/Physics Kristy Halteman http://www.lesia.obspm.fr/~bonnin/fichiers/images/sun-soho011905-1919z.jpg A. Properties 1. 330,000 times more massive than the Earth. http://www.37signals.com/svn/images/sun_v_planets.jpg

### 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

### The Sun Closest star to Earth - only star that we can see details on surface - easily studied Assumption: The Sun is a typical star

The Sun Closest star to Earth - only star that we can see details on surface - easily studied Assumption: The Sun is a typical star Why is the Sun hot and bright? Surface Temperature of the Sun: T =

### 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

### Stellar Astronomy Sample Questions for Exam 3

Stellar Astronomy Sample Questions for Exam 3 Chapter 7 1. A protostar is formed by a) the rapid expansion of gas from an exploding star. b) the gravitational collapse of a rotating interstellar cloud.

### 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

### Ay 1 Lecture 8. Stellar Structure and the Sun

Ay 1 Lecture 8 Stellar Structure and the Sun 8.1 Stellar Structure Basics How Stars Work Hydrostatic Equilibrium: gas and radiation pressure balance the gravity Thermal Equilibrium: Energy generated =

### 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