1 Stars & Galaxies Chapter 27 Modern Earth Science
2 Chapter 27, Section Characteristics of Stars
3 How do astronomers determine the composition and surface temperature of a star?
4 Composition & Temperature Scientists use the following tools to study stars Telescope Observation Spectral Analysis Hydrogen most common element in stars Helium 2 nd most common Carbon, oxygen, nitrogen and calcium make up rest of stars Surface Temperature indicated by color Blue 35,000 Degrees Celsius Red 3,000 Degrees Celsius OUR SUN 6,000 Degrees Celsius
5 Types & Temps
6 Spectrum Analysis Astronomers use a spectrometer to analyze the light emitted by stars. Spectrometers separate light into different colors, or wavelengths The wavelengths of light emitted by a star tell astronomers what elements the star is made from.
7 Why do stars appear to move to an observer on the Earth?
8 Motion The apparent motion of stars is the motion visible to the unaided eye. Apparent motion is caused by the movement of Earth. Most stars have several types of actual motion. Stars can rotate on an axis Stars can revolve around another star Stars can move toward and away from Earth
9 Star REVOLVING around another Star moving TOWARD & AWAY from Earth Star ROTATING on axis
10 The Doppler Effect Red Shift As a star moves away the Earth, the light it emits appears to become red Most distant galaxies, or large groups of stars, have red shifted spectra,, indicating that these galaxies are moving away from the Earth Star moving TOWARD Earth BLUE SHIFT Star moving AWAY from Earth RED SHIFT
11 Universal Expansion
12 Blue-shift & red-shift
13 How do astronomers measure the distance from the Earth to the stars?
14 Distance to the Stars Distances in space are measured in light- years. Light year (ly)= the distance light travels in one Earth year. Speed of light = 300,000 km/sec 1 ly = 9,500,000,000 km (1 ly = 9.5 trillion kilometers)
15 Light Years
16 Parallax -- The change in position of a nearby star compared with the position of a faraway star is called parallax. Earth In January EARTH SUN Actual Location of Star Apparent Location of Star in July EARTH Earth In July Apparent Location of Star in January
17 What is the difference between absolute magnitude and apparent magnitude?
18 Stellar Magnitudes Astronomers use two scales to determine the brightness of a star Scale #1: How bright does a star appear to be on Earth Apparent Magnitude Scale #2: How bright would a star be if lined up next to all other stars Absolute Magnitude The brightest stars have apparent magnitudes that are negative numbers
19 Actual & Apparent Magnitude
20 Apparent Magnitude
21 Classification of Stars The Hertzsprung-Russell Diagram shows the relationship between the surface temperatures and the absolute magnitudes (luminosity) of stars (also called the H-R H R diagram) See page 554.
22 H-R R diagram
23 Another version of H-R H R diagram Supergiants Giants White Dwarfs Main Sequence Stars
24 Study Questions How do astronomers determine the composition and surface temperature of a star? Why do stars appear to move to an observer on the Earth? How do astronomers measure the distance from the Earth to the stars? What is the difference between absolute magnitude and apparent magnitude?
25 27.2 Stellar Evolution
28 1. How does a protostar develop into a star?
29 1st step - Nebula nebula a large cloud of gas and dust in interstellar space; a region in space where stars are born. When the nebula is compressed, some of the particles move close to each other and are pulled together by gravity.
30 2nd step - Protostar As gravity makes dense regions within a nebula more compact (smaller and more dense), these regions spin and shrink and begin to form a flattened disk. The disk has a central concentration of matter called a protostar.
31 The Birth of a Star A protostar s s temperature continually increases until it reaches about 10,000,000 C. At this temperature, nuclear fusion begins. Nuclear fusion starts by combining hydrogen to form helium. The process releases enormous amounts of energy. The start of nuclear fusion marks the birth of a star.. Once this process begins, it can continue for billions of years.
32 2. How does a main-sequence star generate energy?
33 Main-Sequence Stage The second and longest stage in the life of a star is the main-sequence stage. During this stage, energy continues to be generated in the core of the star as hydrogen fuses into helium. Scientists estimate that over a period of almost 5 billion years, the sun has converted only 5% of its original hydrogen nuclei into helium nuclei.
34 A Delicate Balancing Act As gravity increases the pressure on the matter within the star, the rate of fusion increases. Energy radiated from fusion heats the gas inside the star. The outward pressures of the radiation and the hot gas resist the inward pull of gravity. This equilibrium makes the star stable in size.
35 3. What can happen to a star during and after the giant stage?
36 Giants & Supergiants giant a very large and bright star whose hot core has used most of its hydrogen enters its third stage (called the giant stage). Loss of hydrogen = less fusion = less energy = cooler temperature of the star. As the gases in the outer shell become cooler, they begin to glow with a reddish color. Normal-sized stars become giants (our( Sun). Massive stars become supergiants (Rigel( Rigel).
37 After the Giant Stage Planetary nebulas (normal-size stars) White dwarf (normal) Novas (white dwarf) Supernovas (massive stars) Neutron stars (massive stars) Black holes (really massive stars) MUST be able to explain ONE of these
38 Planetary Nebulas As the star s s outer gases drift away, the remaining core heats these expanding gases. The gases appear as a planetary nebula, a cloud of gas that forms around a sunlike star that is dying.
39 White Dwarf Stars As a planetary nebula disperses, gravity causes the remaining matter in the star to collapse inward. The matter collapses until it cannot be pressed further together. A hot, extremely dense core of matter is left. White dwarfs shine for billions of years before they cool completely.
40 Novas & Supernovas Novas are periodic explosions on white dwarfs that DO NOT destroy the star. Supernovas happen when a star has such a tremendous explosion that it blows itself apart. The explosions of supernovas completely destroy the white dwarf star and may destroy much of the red giant.
41 Neutron Stars neutron star a star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons Stars more massive than the sun do not become white dwarfs. After a star explodes as a supernova, the core may contract into a neutron star.
42 Black Holes black hole an object so massive and dense that even light cannot escape its gravity Some massive stars produce leftovers too massive to become a stable neutron star. These stars contract, and the force of the contraction leaves a black hole.
44 27.3 Star Groups
45 Dividing Up the Sky constellation a group of stars organized in a recognizable pattern In 1930, astronomers around the world agreed upon a standard set of 88 constellations.
46 Naming Constellations Many of the modern names we use for the constellations come from Latin. Some constellations are named for real or imaginary animals, such as Ursa Major (the great bear) or ancient gods or legendary heroes, such as Hercules or Orion.
47 The Constellation Orion
48 Multiple-Star Systems Over half of all observed stars form multiple-star systems. Binary stars are pairs of stars that revolve around each other and are held together by gravity. The center of mass, or barycenter, is somewhere between the two stars. In star systems that have more than two stars, two stars may revolve rapidly around a common barycenter, while a third star revolves more slowly at a greater distance from the pair.
49 Star Clusters Sometimes, nebulas collapse to form groups of hundreds or thousands of stars called clusters. Globular clusters have a spherical shape and can contain up to 100,000 stars. An open cluster is loosely shaped and rarely contains more than a few hundred stars.
50 Galaxies galaxy a collection of stars, dust, and gas bound together by gravity Galaxies are the major building blocks of the universe. Astronomers estimate that the universe contains hundreds of billions of galaxies. A typical galaxy, such as the Milky Way, has a diameter of bout 100,000 light-years and may contain more than 200 billion stars.
51 Distances to Galaxies Giant stars called Cepheid variables brighten and fade in a regular pattern. Most Cepheids have regular cycles. The longer the cycle, the brighter the star s s absolute magnitude. Scientists compare the Cepheid s s absolute magnitude and the Cepheid s s apparent magnitude to calculate the distance to the Cepheid variable. This distance tells scientists the distance to the galaxy in which the Cepheid is located.
52 Types of Galaxies Galaxies are classified by shape into three main types. A spiral galaxy has a nucleus of bright stars and flattened arms that spiral around the nucleus. Elliptical galaxies have various shapes and are extremely bright in the center and do not have spiral arms. An irregular galaxy has no particular shape, and is fairly rich in dust and gas.
54 The Milky Way The galaxy in which we live, the Milky Way, is a spiral galaxy in which the sun is one of hundreds of billions of stars. Two irregular galaxies, the Large Magellanic Cloud and Small Magellanic Cloud, are our closest neighbors. These three galaxies are called the Local Group.
55 Quasars quasar quasi-stellar stellar radio source; a very luminous object that produces energy at a high rate. Quasars appear as points of light, similar to stars. Quasars are located in the centers of galaxies that are distant from Earth. Quasars are among the most distant objects that have been observed from Earth.
Stars & Galaxies Chapter 27 Modern Earth Science Chapter 27, Section 1 27.1 Characteristics of Stars Composition & Temperature Scientists use the following tools to study stars Telescope Observation Spectral
Stars and Galaxies 1 Characteristics of Stars 2 Star - body of gases that gives off great amounts of radiant energy as light and heat 3 Most stars look white but are actually different colors Antares -
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.
Stars Stars A star is a ball of different elements in the form of gases The elements and gases give off electromagnetic radiation (from nuclear fusion) in the form of light Scientists study the light coming
Skills Worksheet Directed Reading A Section: The Life Cycle of Stars TYPES OF STARS (pp. 444 449) 1. Besides by mass, size, brightness, color, temperature, and composition, how are stars classified? a.
Beyond Our Solar System Chapter 24 PROPERTIES OF STARS Distance Measuring a star's distance can be very difficult Stellar parallax Used for measuring distance to a star Apparent shift in a star's position
Prentice Hall EARTH SCIENCE Tarbuck Lutgens Chapter 25 Beyond Our Solar System 25.1 Properties of Stars Characteristics of Stars A constellation is an apparent group of stars originally named for mythical
The Universe is space and everything in it. Galaxies A galaxy is a supercluster of stars, gas, and dust that are held together by gravity. There are three main types of galaxies: Irregular Elliptical Spiral
Stars Studying Stars Astronomers use a spectroscope to study the movement of stars Blue shift towards earth Red shift away from earth Change in a wavelength moving toward or away from earth is the Doppler
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
The Night Sky The Universe Chapter 14 Homework: All the multiple choice questions in Applying the Concepts and Group A questions in Parallel Exercises. Celestial observation dates to ancient civilizations
25.2 Stellar Evolution By studying stars of different ages, astronomers have been able to piece together the evolution of a star. Star Birth The birthplaces of stars are dark, cool interstellar clouds,
Classifying Stars In the early 1900s, Ejnar Hertzsprung and Henry Russell made some important observations. They noticed that, in general, stars with higher temperatures also have brighter absolute magnitudes.
Earth Science, 13e Tarbuck & Lutgens Beyond Our Solar System Earth Science, 13e Chapter 24 Stanley C. Hatfield Southwestern Illinois College Properties of stars Distance Distances to the stars are very
I. Stars have color, brightness, mass, temperature and size. II. Distances to stars are measured using stellar parallax a. The further away, the less offset b. Parallax angles are extremely small c. Measured
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
the nature of the universe, galaxies, and stars can be determined by observations over time by using telescopes The spectral lines of stars tell us their approximate composition Remember last year in Physics?
CHAPTER 28 STARS AND GALAXIES 28.1 A CLOSER LOOK AT LIGHT Light is a form of electromagnetic radiation, which is energy that travels in waves. Waves of energy travel at 300,000 km/sec (speed of light Ex:
Name: Block: Stellar Evolution Notes Stars mature, grow old and die. The more massive a star is, the shorter its life will be. Our Sun will live about 10 billion years. It is already 5 billion years old,
Branches of Earth Science Chapter 21: Stars Notes Astronomy: The study of planets, stars, and other objects in space. Lithosphere: the land masses of earth o Litho means rock Hydrosphere: waters of the
Chapter 28 Stars and Their Characteristics Origin of the Universe Big Bang Theory about 10-20 bya all matter in the universe existed in a hot dense state about the size of an atom (tiny). That matter sort
Cosmology, Galaxies, and Stars OUR VISIBLE UNIVERSE Cosmology Cosmology is the study of the universe; its nature, origin and evolution. General Relativity is the mathematical basis of cosmology from which
chapter 31 Stars and Galaxies Day 1:Technology and the Big Bang Studying the Stars A. Telescopes - Electromagnetic radiation emitted by stars and other objects include light, radio, and X-ray Space telescopes
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
Exam # 3 Tue 12/06/2011 Astronomy 100/190Y Exploring the Universe Fall 11 Instructor: Daniela Calzetti INSTRUCTIONS: Please, use the `bubble sheet and a pencil # 2 to answer the exam questions, by marking
Directions: For numbers 1-30 please choose the letter that best fits the description. 1. The main force responsible for the formation of the universe is: a. Gravity b. Frictional force c. Magnetic force
STARS Instructions Students will underline the portions of the PowerPoint that are underlined. Nuclear Furnace 1. A star is like a gigantic nuclear furnace. 2. The nuclear reactions inside convert hydrogen
Ch. 25 In-Class Notes: Beyond Our Solar System ES2a. The solar system is located in an outer edge of the disc-shaped Milky Way galaxy, which spans 100,000 light years. ES2b. Galaxies are made of billions
stars The night sky is filled with stars that shine at different levels of brightness. The brightness of the stars we observe can be related to the size of the star or its distance from Earth. In order
TEACHER BACKGROUND INFORMATION (The Universe) A. THE UNIVERSE: The universe encompasses all matter in existence. According to the Big Bang Theory, the universe was formed 10-20 billion years ago from a
NSCI 314 LIFE IN THE COSMOS 2 BASIC ASTRONOMY, AND STARS AND THEIR EVOLUTION Dr. Karen Kolehmainen Department of Physics CSUSB COURSE WEBPAGE: http://physics.csusb.edu/~karen MOTIONS IN THE SOLAR SYSTEM
Stars, Galaxies, Use Target Reading Skills Check student definitions for accuracy. 1. Electromagnetic radiation is energy that can travel through space in the form of waves. 2. visible light 3. wavelength
Textbook Chapters 24 - Stars Textbook Chapter 25 - Universe Regents Earth Science with Ms. Connery SPECTROSCOPY is the study of light. Read to learn - textbook pages 674-677 STAR LIGHT gives us characteristics
Life Cycle of a Star Worksheet A STAR IS BORN STAGES COMMON TO ALL STARS All stars start as a nebula. A nebula is a large cloud of gas and dust. Gravity can pull some of the gas and dust in a nebula together.
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
Section: Stars Pages 32-38 Study Guide Chapter 2 Circle the letter of the best answer for each question. 1. What do scientists study to learn about stars? a. gravity c. space b. starlight d. colors COLOR
Chapter 21 Earth Science 11 Constellations Constellation: A group of stars that appear to form patterns in the sky. 88 different constellations can be seen from the Northern and Southern hemispheres Best
10/26/16 Lecture Outline 13.1 Star Birth Chapter 13: Star Stuff How do stars form? Our goals for learning: How do stars form? How massive are newborn stars? Star-Forming Clouds Stars form in dark clouds
The Formation of Stars A World of Dust The space between the stars is not completely empty, but filled with very dilute gas and dust, producing some of the most beautiful objects in the sky. We are interested
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
GALAXIES AND STARS 1. Compared with our Sun, the star Betelgeuse is A smaller, hotter, and less luminous B smaller, cooler, and more luminous C larger, hotter, and less luminous D larger, cooler, and more
Edwin Hubble Discovered galaxies other than the milky way. Galaxy: A collection of stars, planets, gas, and dust that are held together by gravity. Our sun and planets are in the Milky Way He noticed that
CORNELL NOTES Directions: You must create a minimum of 5 questions in this column per page (average). Use these to study your notes and prepare for tests and quizzes. Notes will be turned in to your teacher
PHYS103 Sec 901 Hour Exam No. 3 Page: 1 PHYS103 Sec 901 Hour Exam No. 3 Page: 2 1 The star alpha-centauri C has moved across the sky by 3853 seconds of arc during the last thousand years - slightly more
Lecture 4 Stars The physics of stars A star begins simply as a roughly spherical ball of (mostly) hydrogen gas, responding only to gravity and it s own pressure. X-ray ultraviolet infrared radio To understand
What is the sun? The sun is a star at the center of our solar system. Galileo Galilei (1564-1642) Galileo was one of the first Europeans to observe the sun. How did Galileo look at the sun? He lined up
Stars Star- large ball of gas held together by gravity that produces tremendous amounts of energy and shines Sun- our closest star Star Formation A cloud of gas and dust, called a nebula, begins spinning
Stars, Galaxies, and the Universe Chapter Test A Multiple Choice Write the letter of the correct answer on the line at the left. 1. What is a giant ball of hot gases that undergo nuclear fusion? a. a planet
Stellar Evolution Review: HR Diagram Label A, B, C respectively A C B a) A: White dwarfs, B: Giants, C: Main sequence b) A: Main sequence, B: Giants, C: White dwarfs c) A: Main sequence, B: White Dwarfs,
240 points CHAPTER 29 STARS SECTION 29.1 The Sun (40 points this page) In your textbook, read about the properties of the Sun and the Sun s atmosphere. Use each of the terms below just once to complete
Generally speaking, there are two main life cycles for stars. The factor which determines the life cycle of the star is its mass. 1 solar mass = size of our Sun Any star less than about three solar masses
Earth Space Systems Semester 1 Exam Astronomy Vocabulary Astronomical Unit- Aurora- Big Bang- Black Hole- 1AU is the average distance between the Earth and the Sun (93 million miles). This unit of measurement
STARS CHAPTER 10.1 the solar neighborhood The distances to the nearest stars can be measured using Parallax => the shift of an object relative to some distant background as the observer s point of view
StarTalk Sanjay Yengul May 2016 "To know ourselves, we must know the stars." Twinkle Twinkle How many stars are there? How big are these stars? Picture of night sky What are they made of? Why do they shine?
Phys 0 Astronomy (Dr. Ilias Fernini) Review Questions for Chapter 9 MULTIPLE CHOICE 1. We know that giant stars are larger in diameter than the sun because * a. they are more luminous but have about the
CHAPTER 4 STARS, GALAXIES & THE UNIVERSE LESSON 1: TELESCOPES ALL TYPES OF ELECTROMAGNETIC RADIATION TRAVEL AT THE SPEED OF LIGHT 186,000 miles per second!! Electromagnetic Radiation = energy that travels
Introduction to the Universe What makes up the Universe? Objects in the Universe Astrophysics is the science that tries to make sense of the universe by - describing the Universe (Astronomy) - understanding
The Universe and Galaxies 16.1 http://dingo.care-mail.com/cards/flash/5409/galaxy.swf Universe The sum of all matter and energy that exists, that has ever existed, and that will ever exist. We will focus
ASTRONOMY Universe- Includes all known matter (everything). Celestial Object Any object outside or above Earth s atmosphere. Galaxy- A large group (billions) of stars (held together by gravity). Our galaxy
Astronomy 132 - Stars, Galaxies and Cosmology Exam 3 Please PRINT full name Also, please sign the honor code: I have neither given nor have I received help on this exam The following exam is intended to
Chapter 12 Review TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 1) As a main-sequence star, the Sun's hydrogen supply should last about 10 billion years from the zero-age
Protostars on the HR Diagram Once a protostar is hot enough to start, it can blow away the surrounding gas Then it is visible: crosses the on the HR diagram The more the cloud, the it will form stars Lifetimes
Astronomy Universe: all of space and everything in it Most (90%) of the universe is made up of: dark matter: stuff we think is there due to amount of mass we think is there but is not detected by the instruments
chapter 13 3 Stars and Galaxies section 3 Evolution of Stars Before You Read What makes one star different from another? Do you think the Sun is the same as other stars? Write your ideas on the lines below.
What makes up the Universe? Introduction to the Universe Book page 642-644 Objects in the Universe Astrophysics is the science that tries to make sense of the universe by - describing the Universe (Astronomy)
Guiding Questions Stellar Evolution 1. Why do astronomers think that stars evolve? 2. What kind of matter exists in the spaces between the stars? 3. What steps are involved in forming a star like the Sun?
Name: Period: Date: Astronomy Ch. 21 Stellar Explosions MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A surface explosion on a white dwarf, caused
Star Deaths Why Do Stars Leave the Main Sequence? Running out of fuel Observing Stellar Evolution by studying Globular Cluster HR diagrams Plot stars in globular clusters in Hertzsprung-Russell diagram
Stars and Galaxies Evolution of 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 agree with the statement
Clicker Questions (chapters 6-18) 1. Officially, how many planets are there in our solar system? a. 8 b. 9 c. dozens 2. The Doppler formula is v = ( λ/λ) 300,000 km/sec for light waves. A particular feature
Light Transverse electromagnetic wave, or electromagnetic radiation Includes radio waves, microwaves, infra-red, visible, UV, X-rays, and gamma rays The type of light is determined purely by wavelength.
Protostars on the HR Diagram Once a protostar is hot enough to start, it can blow away the surrounding gas Then it is visible: crosses the on the HR diagram The more the cloud, the it will form stars Lifetimes
The Sun - It is located at the centre of our solar system with all planets and objects (comets and asteroids) revolving around it Page 1 of 6 - It s gravitational pull keeps the planets and other objects
Astro 21 first lecture The H-R H R Diagram helps us study how stars are born but also helps us study how they die. Stars spend most of their lives as main sequence stars. The core does change from hydrogen
Life Cycle of a Star Video (5 min) http://www.youtube.com/watch?v=pm9cqdlqi0a The Life Cycle of Stars Solar Nebula Theory : Is the current theory of how our Solar System formed. This theory states that
Name: Class: _ Date: _ Geoscience Astronomy Formative on Stellar Evolution and Galaxies Multiple Choice Identify the choice that best completes the statement or answers the question. 1. What are binary
A. Solar system: stability of orbital motions; satellites (physics only) 1. Put these astronomical objects in order of size from largest to smallest. (3) Fill in the boxes in the correct order. the Moon