Stars. The size of the Sun

Size: px
Start display at page:

Transcription

1 Stars Huge spheres of gas floating in space Composed primarily of H, He. Produce their own energy. Our Galaxy: (100 billion) stars. The Sun: a typical star Stars range from ~ 0.1 to ~ 20 M M = solar mass Individual stars evolve as they age sun is in middle of its ~ year lifespan. The size of the Sun Diameter: 1.4x10 6 km 109 x Earth Mass: 2x10 33 g 333,000 x Earth Distance from Earth 93 million miles 1.5x10 8 km 8 light minutes Luminosity (amount of energy emitted per unit time): 4x10 26 watts times average power consumption of US.

2 The Composition of the Sun From spectroscopy of outer layers [Table 14.2] The Interior of the Sun (almost) no observations of interior Interior structure deduced from observing the outside Luminosity Mass

3 What Powers the Sun? Need to provide 4x10 26 watts < 2x10 33 grams (mass of Sun) > 4.5 billion years (age of Earth) Duracell batteries? A single D-cell: 0.5 watts/battery ==> 8x10 26 batteries required. 139g/battery ==> batteries total room for 20,000 times more batteries in reserve. but each battery lasts only 43 hours 43 hrs x 20,000 = 98 years. Gravitational contraction? Converts gravitational potential energy into kinetic energy Kinetic energy in a gas = heat Collisions between atoms convert heat to light To provide 4x10 26 watts sun must contract by 40 meters per year 40m x 2000 years of observations: undetectable! But total available gravitational energy = Joules 1 watt = 1 Joule/second J / 4x10 26 J/s = 2.5x10 15 seconds = 79 million years. 800,000 x better than Duracell batteries But not good enough (we need > 4.5 billion years).

4 Hydrogen: 1 H What Powers the Sun? Need to provide 4x10 26 watts < 2x10 33 grams (mass of Sun) > 4.5 billion years (age of Earth) How about H bombs? 4 x 1 H 4 He + neutrinos + energy Helium: 4 He 4 x Special Relativity E = mc 2 The Principal of Relativity. The laws of physics are the same in all inertial reference frames. The constancy of the speed of light. Light travels through a vacuum at a speed c which is independent of the light source. distance, time, velocity add up in funny ways 60 mph 100 mph Classical: v = (v-u) Special relativity: v = (v-u)/(1-uv/c 2 ) Total energy of a particle moving at constant velocity v: Classical: E = 1/2 mv 2 Special relativity: E = mc 2 / 1-v 2 /c 2 ~ 1/2 mv 2 + mc 2 Rest Energy is there even when v = 0 Kinetic energy

5 How about H bombs? 4 x 1 H 4 He + neutrinos + energy Hydrogen: 1 H Helium: 4 He 4 x Atomic structure Proton: + charge, x10-27 kg Neutron: 0 charge, x10-27 kg Electron: - charge, 9.11 x10-31 kg Neutrino: 0 charge, 0(?) mass [Table 15.1] Mass to Energy 4 x 1 H 4 He + neutrinos + energy E = mc 2 is one way to describe how much energy is released. Mass of 4 x 1 H 4 x ( x10-27 kg) x10-27 kg = = = Mass of 4 He x10-27 kg x10-27 kg The neutrinos have negligible mass...so x mass of H is converted to energy x 2 x kg x (3 x 10 8 m/s) 2 = Joules (total available energy) Mass of Sun c 2 (Available energy) / (Luminosity) = J / 4 x W = 3x10 18 s Actual number ~ yrs because Sun will evolve after central 10% of its mass is consumed, and then will die. = years

6 The proton-proton fusion reaction See [Figs 15.4,15.5] Starts with energetic collisions between pairs of protons. Intermediate products are deuterium ( 2 H) and 3 He. End result: 4 1 H 4 He + neutrinos + energy Electrostatic Repulsion F 1/r 2 But must get past coulomb barrier (electrostatic repulsion) before reaction can occur. Energy Need at least this much energy to be able to get close enough for strong nuclear force to grab hold. Energy comes from kinetic energy = 1/2 mv 2 of colliding protons. High temperature = large kinetic energy.

7 Alternate mechansim - the Carbon-Nitrogen-Oxygen (CNO) cycle CNO cycle: 12 C + 1 H 13 N + γ 13 N 13 C + e + + ν 13 C + 1 H 14 N + γ 14 N + 1 H 15 O + γ 15 O 15 N + e + + ν 15 N + 1 H 12 C + 4 He γ = gamma ray (light) Uses carbon ( 12 C) as a catalyst. ν = neutrino So only works if C (or N or O) already present in star. Net result: 4 1 H 4 He + neutrinos + energy Computing the structure of the sun For every point in the Sun, we want to compute temperature pressure density composition energy generation energy transport mechanism We can write 4 equations expressing the following ideas: The Sun is a gas. The sun is neither contracting nor expanding. The sun is neither heating up nor cooling down. Specify method of energy transfer. See [15.3]

8 The Sun is a gas: pressure density x temperature P ρ x T The sun is neither contracting nor expanding: Pressure support from below = gravitational attraction towards center dp/dr = -GM r ρ / r 2 M r = mass interior to r Spherical shells outside radius of r have no net gravitational effect. Mass interior to r has same gravitational attraction as if it were all exactly at the center. Radius r [Fig 15.7] The sun is neither heating up nor cooling down Equation saying that at each point in the star: Energy losses = energy generation dl r /dr = 4πr 2 ρε ε = energy generation complicated, but known, function of density, temperature and composition. Energy generation changes composition 4 1 H 4 He + neutrinos + energy

9 Energy transfer Possibilities are: Radiation photons (light) travel a short distance. absorbed by atoms. re-emitted. random walk. Convection hot bubbles rise. cooler bubbles fall. occurs when pressure changes very little with temperature. Conduction Not important in Sun [Fig 15.9] [Fig 15.8] The Resulting Model of the Sun H 4 He composition temperature Energy generation 3 He density pressure Energy transport mass radius

10 The solar interior Central Conditions Temperature: 1.6x10 7 K Pressure: 2.5x10 11 atm Density: 162 g/cm 3 % H (by mass): % He: [Fig 15.11] Solar oscillations 2D mapping of velocity of gas on Sun s surface Seismic wave patterns. Caused by sudden collapses of large volumes of gas on surface. Wave pattern shows interior structure similar to analysis of Earth s, Moon s interior structures. GONG network continuously maps Sun s surface velocity field. Results Convection zone down to 30% of Sun s radius. Differential rotation throughout convection zone. Helium abundance same as at surface, except in energy generation zone. [Fig 15.12]

11 The solar neutrino problem 4 1 H 4 He + neutrinos + energy [Fig 15.10] Observed luminosity of sun number of neutrinos produced. Neutrinos very hard to measure. Only interact through weak nuclear force. Initial measurements show only 1/3 expected rate of neutrinos. Super Kamiokande Neutrino Detector (Japan) Large chamber deep underground. Filled with pure water. Neutrinos interact (weakly) with water. 13,000 photocells on walls detect resulting Cherenkov radiation. Found neutrino oscillations Three types of neutrinos known. Neutrinos change back and forth between types while in transit. Previous experiments only sensitive to one type. DECEASED

12 The Surface of the Sun Most stars are so far away that no surface detail can be resolved Sun is only example where we can make a detailed study Surfaces of other stars presumably similar.

13 Photosphere Deepest layer from which light directly escapes into space. Low density and pressure (10-4, 0.1 x Earth s surface values) But hot (5800 o K) Granules (in photosphere) Tops of convection currents. Chromosphere Transparent gas layer, reaches km above photosphere. T ~5,000-10,000 o K Photosphere = point we can no longer see through chromosphere. Corona T > 1,000,000 o K Very low density: bar. Heated by magnetic energy. Several x diameter of photosphere.

14 Transition region Interface between Chromosphere & Corona Spicules Small jets of cooler Chromospheric gas squirting up into Corona Come and go on 10 minute timescale Magnetic Field Lines Force B (mag field) velocity Motion of a charged particle around a magnetic field line The Sun s magnetic field Magnetic field lines of force

15 The Solar Wind Hot gas boils off surface of sun Ionized: collisions knock electrons off atoms. Magnetic field controls movements of charged particles. Solar wind escapes through holes in magnetic fields Escape velocity v escape = 2GM/R = 600 km/s Only ~ 50 x higher than from Earth s surface But corona has T > 10 6 degrees Very highest energy atoms have escape velocity Solar wind flows outward at 400 km/s (900,000 mph). Charged particles then interact with Earth s atmosphere (auroras) Comet tails But it actually involves a very complicated interaction with the Sun s magnetic field. Sunspots Cooler areas as much as 1500 o less than photosphere. This makes them look darker. But they actually are still very bright. Glowing at 4300 o K instead of 5800 o

16 Sunspots occur where magnetic field lines leave, re-enter photosphere. Spots come in pairs. leading = 1 magnetic polarity trailing = opposite polarity polarity reveres between N, S hemispheres. Magnetic field prevents hotter gas (granules) from entering these regions. Sunspots rotate with Sun s surface 36 days of the magnetic sun movie

17 The Sunspot Cycle 11 years between maxima. we are currently in a maximum. The Butterfly Diagram: shows change in latitude of sunspots during repeating sunspot cycles. The Sunspot Cycle Caused by cyclical change in Sun s magnetic field. field reverses polarity on 22 year cycle. reverses polarity of leading spots in pairs. Sunspots are a detail showing how the Sun s magnetic field is leaking out of the zones just below the Sun s surface. Magnetic field seems to be produced in outer 30% of Sun s radius. Carroll & Ostlie, Modern Astrophysics

18 Activity in the Chromosphere and Corona Plages - hot regions in the chromosphere Prominences Flame-like protuberances usually above sunspots follow magnetic field lines ==> loops eruptive prominences shoot out material at > 1000 km/s well above 600 km/s escape velocity many times the size of Earth Lots of prominences X-ray pictures from Yohkoh satellite

19 Solar Flares Most violent solar activity caused by magnetic fields shorting out can eject large amounts of material from corona can dump huge numbers of fastmoving protons into Earth s atmosphere 1989 power outage in Canada temporarily heated and expanded Earth s atmosphere Connections between the layers Movie comparing x-rays to white light. Movie starting with photosphere, then chromosphere, then x-ray view of corona. Note the connections between locations of sunpots in photosphere, and activity further out. The Corona in X-rays Movie showing coronal activity seen by Yohkoh satellite, as the Sun rotates (24 day period).

20 1995 X-rays The solar cycle H emission 1991 sunspot maximum Differential rotation of Sun s outer layers 24 days at equator. 30 days at pole. reason not understood. Winds up magnetic field field reverses each 11 yrs, when it gets too wound up. causes 22-year cycle. but why this reversal??? We don t know. What causes the solar cycle? Carroll & Ostlie, Modern Astrophysics

21 Variations in Cosmic Ray Rates Cosmic rays: high energy charged particles from outside solar system. Produce radioactive 14 C which then gets locked up in plant material. Higher solar activity = stronger solar magnetic field. this shields Earth from cosmic rays. 14 C concentrations in tree rings history of solar activity but smeared out over ~ 10 years it takes 14 C to find its way into plants. Goes back 8000 years. The long-term record on Earth Cool periods (Maunder minimum, little ice age ) (Little Maunder minimum) Warm period before 1280 coincided with Norse discovery of New World. Today, Sun puts out ~ 0.1% more light at sunspot maximum than at sunspot minimum. But 10 x bigger variation needed to explain temperatures during Maunder minimum.

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 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

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

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 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. 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 =

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

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

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

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.

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

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

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

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. 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

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

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

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

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

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: A Star of Our Own ASTR 2110 Sarazin

The Sun: A Star of Our Own ASTR 2110 Sarazin Sarazin Travel Wednesday, September 19 afternoon Friday, September 21 Will miss class Friday, September 21 TA Molly Finn will be guest lecturer Cancel Office

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?

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

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

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

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

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

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

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

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 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

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

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?

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)

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

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?

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:

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

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

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!!

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

Reading Clicker Q 2/7/17. Topics for Today and Thur. ASTR 1040: Stars & Galaxies

ASTR 1040: Stars & Galaxies Solar granulation Prof. Juri Toomre TAs: Piyush Agrawal, Connor Bice Lecture 7 Tues 7 Feb 2017 zeus.colorado.edu/astr1040-toomre Topics for Today and Thur Consider Sun s energy

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

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

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 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?

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

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

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:

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

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

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

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 =

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

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 =

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

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

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

Our Sun Our Star. Image credit: JAXA. OU-L P SC 100 Spring, /81

Our Sun Our Star Image credit: JAXA OU-L P SC 100 Spring, 2009 1/81 1 Diameter: 1,400,000 km = 864,000 miles = 4.5 light-seconds 1,300,000 Earths could fit inside! 109 Earths would fit across the diameter

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 interior of the Sun. Space Physics - Project by Christopher Keil. October 17, Supervisor: Prof. Kjell Rnnemark

The interior of the Sun Space Physics - Project by Christopher Keil October 17, 2006 Supervisor: Prof. Kjell Rnnemark Umeå University Institute of Physics Contents 1 Introduction 2 2 The Structure of the

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.

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

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

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

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

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

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?

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

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

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

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

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

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?

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:

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.

Stellar Structure. Observationally, we can determine: Can we explain all these observations?

Stellar Structure Observationally, we can determine: Flux Mass Distance Luminosity Temperature Radius Spectral Type Composition Can we explain all these observations? Stellar Structure Plan: Use our general

Stellar Interior: Physical Processes

Physics Focus on Astrophysics Focus on Astrophysics Stellar Interior: Physical Processes D. Fluri, 29.01.2014 Content 1. Mechanical equilibrium: pressure gravity 2. Fusion: Main sequence stars: hydrogen

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

The Sun - II. Alexei Gilchrist

The Sun - II Alexei Gilchrist Some resources http://www.nineplanets.org/sol.html The Universe: Secrets of the Sun video Search on youtube Secrets of the Sun (references are to clips here http://www.youtube.com/view_play_list?p=4eef5255d3eef425

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

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

2/6/18. Topics for Today and Thur. ASTR 1040: Stars & Galaxies. EUV and Visible Images

2/6/18 ASTR 1040: Stars & Galaxies Topics for Today and Thur Consider Sun s energy source (fusion H--He) Solar granulation Prof. Juri Toomre TAs: Peri Johnson, Ryan Horton Lecture 7 Tues 6 Feb 2018 What

A100 Exploring the Universe: How Stars Work. Martin D. Weinberg UMass Astronomy

A100 Exploring the Universe: How Stars Work Martin D. Weinberg UMass Astronomy weinberg@astro.umass.edu October 11, 2012 Read: Chaps 14, 15 10/11/12 slide 1 Exam scores posted in Mastering Exam keys posted

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

Unit 1: Space. Section 2- Stars

Unit 1: Space Section 2- Stars Stars Recall: stars are celestial bodies of hot gas that give off heat and light Stars The milky way contains hundreds of billions of stars and is only one of hundreds of

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

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 ~

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

Lecture 14: The Sun and energy transport in stars. Astronomy 111

Lecture 14: The Sun and energy transport in stars Astronomy 111 Energy transport in stars What is a star? What is a star composed of? Why does a star shine? What is the source of a star s energy? Laws

! The Sun as a star! Structure of the Sun! The Solar Cycle! Solar Activity! Solar Wind! Observing the Sun. The Sun & Solar Activity

! The Sun as a star! Structure of the Sun! The Solar Cycle! Solar Activity! Solar Wind! Observing the Sun The Sun & Solar Activity The Sun in Perspective Planck s Law for Black Body Radiation ν = c / λ

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

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:

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,

Hydrogen Burning in More Massive Stars and The Sun.

Hydrogen Burning in More Massive Stars and The Sun http://apod.nasa.gov/apod/astropix.html 2 min For temperatures above 18 million K, the CNO cycle dominates energy production 10 min CNO 14 N CNO CYCLE