# AST 248, Lecture 2. James Lattimer. Department of Physics & Astronomy 449 ESS Bldg. Stony Brook University. January 28, 2015

Save this PDF as:

Size: px
Start display at page:

Download "AST 248, Lecture 2. James Lattimer. Department of Physics & Astronomy 449 ESS Bldg. Stony Brook University. January 28, 2015"

## Transcription

1 AST 248, Lecture 2 James Lattimer Department of Physics & Astronomy 449 ESS Bldg. Stony Brook University January 28, 2015 The Search for Life in the Universe

2 Distances in Astronomy Radius of Earth ( ): R = cm = 3977 miles Radius of Sun ( ): R = cm = 435, 000 miles Earth Sun distance: 1 Astronomical Unit (1 AU) = cm =93,000,000 miles light-year = cm (1 year = s and c = cm/s) 1 lt.-yr. = cm parsec (pc) = AU/tan(1 ) = cm (3.26 lt.-yr.) D(pc) = 1/θ( ) since tan θ θ for very small angles. 1 kpc = 10 3 pc 1 Mpc = 10 6 pc

3 Size of the Earth: Eratosthenes (about 240 BC) Eratosthenes knew at noontime on the summer solstice (June 21) the Sun was directly overhead at Syene (southern Egypt) because the bottom of a vertical well was illuminated. At the same time in Alexandria, which is due north, the Sun cast a shadow which Eratosthenes measured to be a θ = 7 angle from the vertical, about 1/50 of a complete circle. The estimated distance between the cities is about D = 500 miles. The circumference of the Earth must be 50 times 500 miles or 25,000 miles.

4 Earth Moon: Aristarchus (270 BC) In a total lunar eclipse, the Moon passes through the Earth s shadow. Aristarchus observed that it took about 3 hours for the mid-point of the Moon to cross the center of the shadow. He reasoned that the width of the Earth s shadow is the same as its diameter. If the Moon moves around the Earth at a constant speed, and it takes about 29.5 days for the Moon to complete one orbit, then Circumference of orbit Lunar month = Diameter of Earth Duration of eclipse = 2πR = = 236 2R 3 Then the distance to the Moon is 236/π = 75 times the Earth s radius. The correct value is 60, because the Earth s shadow is a cone, and is 25% smaller at the Moon.

5 Earth Moon: Hipparchus (128 BC) In a total solar eclipse, the Moon barely covers the Sun. Hipparchus used the fact that while the eclipse was total at Hellespont (Turkey) it was only 4/5 total at Alexandria. Since the angular diameter of the Sun (and Moon) is 0.5, the angle α = 0.1. The latitudes of these cities differ by AB = 2πR = 2πR The distance to the Moon is R = 9R /.1 = 90R. The error is due to the Moon not being overhead at the time of the ecipse, but at an angle of from the zenith.

6 Distance to the Sun: Aristarchus (about 270 BC) Aristarchus felt that the Moon orbits the Earth and the Earth-Moon system orbits the Sun. He reasoned that when the Moon was exactly half lit by the Sun that the Earth-Moon-Sun angle was 90. If the Sun was infinitely far away, then the angle α would also have to be 90 and the angle β = 0. Aristarchus estimated however, that the angle β was about 3, and β = D M E D E S 360 2π. Therefore D E S /D E M = 360 2πβ = 19. This is too small by about a factor of 20. β

7 Distance to the Sun: Cassini and Richer (1672) They used a measurement of the parallax of Mars to determine the distance to Mars, and then inferred the distance to the Sun using Kepler s Laws. Richer traveled to Cayenne, French Guiana, while Cassini remained in Paris to simultaneously measure the location of Mars in the sky at a relatively near approach (conjunction). They obtained a value 20 times larger than Aristarchus which had been the accepted value up to that point.

8 Cosmic Distance Ladder Parallax Establish a database of stellar distances to thousands of nearby stars. Inverse Square Law of Brightness Stars established to be similar (color, spectra, etc.) have similar luminosities. Their relative brightnesses then yield their relative distances. Statistical, Secular and Moving Cluster Parallexes Cepheid and RR Lyrae Variable Stars as Standard Candles Henrietta Leavitt discovered in 1912 the period-luminosity relation among Cepheid variables. They are now used as standard candles. zebu.oregon.edu

9 Velocity Measurements With Redshifts Planetary nebulae, novae, supernovae, orbiting stars. Tully-Fisher Relation Relation between the observed velocity width (amplitude of rotation curve) and luminosity of spiral galaxies. Type I Supernovae Exploding white dwarfs of similar masses yield similar luminosities and therefore are good standard candles. Redshifts of Galaxies, Quasars and Gamma-Ray Bursters

10 The Universe Reduced by a Billion Object Size Distance from Earth Earth 1.3 cm (grape) Moon.35 cm (corn kernal) 1 foot Sun 1.4 m (child s height) 150 m (1 city block) Jupiter 15 cm (grapefruit) 5 city blocks Saturn 12 cm (orange) 10 city blocks Uranus 5.2 cm (apricot) 20 city blocks Neptune 5 cm (plum) 30 city blocks Pluto 0.23 cm (rice grain) 40 city blocks α Centauri 1.6 m (small adult) Earth s circumference Center of Galaxy 1.7 AU Andromeda Galaxy Sun Pluto distance 400 AU Human atom

11 Energy and Luminosity (Power) Power and Luminosity are equivalent Power is Energy/Time, or Energy = Power Time Luminosity of the Sun: L = erg/s = kw = hp 1 watt = 10 7 erg/s;1 kilowatt = 10 3 watt 1 kilowatt-hour = 1 kwh = erg 1 horsepower = 1 hp = 0.75 kw 1 BTU = erg = kw-second 1 megaton TNT = kwh

12 Economics of Solar Power On Long Island, 1 kwh costs \$0.17 The world s annual energy use is about ergs \$ = \$47T The world s power use thus averages erg/s = 32 billion kw The Solar Constant is solar energy received per unit area per second at the Earth: L = erg watt = π(1 AU) 2 cm 2 s cm 2 A collector of cm 2 = 9300 mi 2 area operating at 100% efficiency is needed to continuously supply the world.

13 Mass Mass of the Sun: M = g Mass of the Earth: M = g = lb. = tons = M M Jupiter = g = 318 M = M Mass energy equivalence stated in Einstein s Law: E = Mc 2 Energy equivalent of the Sun: E = M c 2 = erg Implied lifetime of the Sun: τ E /L = s = yr = 17,000 Gyr (1 Gyr = 10 9 yr) Nuclear energy reactions in the Sun are only.007 (0.7%) efficient, and only the innermost 10% of the Sun will ever be burned : τ = 17, billion yrs = 12 billion yrs

14 Kepler s Laws 1. Law of Orbits: planets move in elliptical orbits with Sun at one focus. 2. Law of Areas: a line connecting a planet with the Sun sweeps out equal areas in equal times. 3. Law of Periods: The square of a planet s orbital period (year) is proportional to the cube of its semimajor axis (distance from Sun).

15 Mass Measurements Kepler s Law G(M 1 + M 2 )P 2 = 4π 2 (R 1 + R 2 ) 3 Measure orbital period P. Measure stellar velocity V 1 from maximum Doppler shift of spectral lines. The circumference of M 1 s orbit is 2πR 1 = PV 1. Total mass is M 1 + M 2 = PV 3 1 (1 + M 1 /M 2 ) 3 /(2πG). If M 2 >> M 1 then M 2 = PV 3 1 /(2πG). Caveat: inclination angle should be known to find V 1. If V 2 is also measured, then both M 1 and M 2 can be found. Gravitational Lensing Position in Hertzsprung-Russell Diagram Estimates Based on Luminosity Applied to molecular clouds and galaxies.

### Lecture #4: Plan. Early Ideas of the Heavens (cont d): Geocentric Universe Heliocentric Universe

Lecture #4: Plan Early Ideas of the Heavens (cont d): Shape & size of the Earth Size & distance of Moon & Sun Geocentric Universe Heliocentric Universe Shape of the Earth Aristotle (Greece, 384 322 B.C.)

### How big is the Universe and where are we in it?

Announcements Results of clicker questions from Monday are on ICON. First homework is graded on ICON. Next homework due one minute before midnight on Tuesday, September 6. Labs start this week. All lab

### ASTRONOMY QUIZ NUMBER 1

ASTRONOMY QUIZ NUMBER. You read in an astronomy atlas that an object has a negative right ascension. You immediately conclude that A) the object is located in the Southern Sky. B) the object is located

### AST-1002 Section 0459 Review for Final Exam Please do not forget about doing the evaluation!

AST-1002 Section 0459 Review for Final Exam Please do not forget about doing the evaluation! Bring pencil #2 with eraser No use of calculator or any electronic device during the exam We provide the scantrons

### Galaxies & Introduction to Cosmology

Galaxies & Introduction to Cosmology Other Galaxies: How many are there? Hubble Deep Field Project 100 hour exposures over 10 days Covered an area of the sky about 1/100 the size of the full moon Probably

### Benefit of astronomy to ancient cultures

Benefit of astronomy to ancient cultures Usefulness as a tool to predict the weather (seasons) Usefulness as a tool to tell time (sundials) Central Africa (6500 B.C.) Alignments Many ancient cultures built

### Lunar Eclipse. Solar Eclipse

Lunar Eclipse SUN Moon Solar Eclipse SUN SUN Moon Total solar eclipse Partial solar eclipse Moon Phases What does the moon look like from at each position? G H F A E B D C SUNLIGHT Refracting Telescopes

### Lecture 32: The Expanding Universe Readings: Sections 26-5 and 28-2

Lecture 32: The Expanding Universe Readings: Sections 26-5 and 28-2 Key Ideas Measuring the Distances to Galaxies and Determining the Scale of the Universe Distance Methods: Trigonometric Parallaxes Spectroscopic

### Exercise 3: The history of astronomy

Astronomy 100 Name(s): Exercise 3: The history of astronomy In the previous exercise, you saw how the passage of time is intimately related to the motion of celestial objects. This, of course, led many

### Spectroscopy, the Doppler Shift and Masses of Binary Stars

Doppler Shift At each point the emitter is at the center of a circular wavefront extending out from its present location. Spectroscopy, the Doppler Shift and Masses of Binary Stars http://apod.nasa.gov/apod/astropix.html

### Chapter 2. The Rise of Astronomy. Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chapter 2 The Rise of Astronomy Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Periods of Western Astronomy Western astronomy divides into 4 periods Prehistoric

### AST1100 Lecture Notes

AST1100 Lecture Notes 11-12 The cosmic distance ladder How do we measure the distance to distant objects in the universe? There are several methods available, most of which suffer from large uncertainties.

### Galaxies. The majority of known galaxies fall into one of three major classes: spirals (78 %), ellipticals (18 %) and irregulars (4 %).

Galaxies Collection of stars, gas and dust bound together by their common gravitational pull. Galaxies range from 10,000 to 200,000 light-years in size. 1781 Charles Messier 1923 Edwin Hubble The distribution

### The Electromagnetic Spectrum

The Electromagnetic Spectrum Three Kinds of Spectra Sun: The Nearest Star Radius 696,000 km 109 Re Mass 2 x 10^30 kg 300,000 Me Density 1400 kg/m^3 Luminosity 3.8x10^26 Watts (board calc.) Comp. 70% H,

### Practice Test DeAnza College Astronomy 04 Test 1 Spring Quarter 2009

Practice Test DeAnza College Astronomy 04 Test 1 Spring Quarter 2009 Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. Mark answer on Scantron.

### The Stars. Background & History The Celestial Sphere: Fixed Stars and the Luminaries

The Stars Background & History The Celestial Sphere: Fixed Stars and the Luminaries The Appearance of Stars on the Sky Brightness and Brightness Variations Atmospheric Effects: Twinkling Variable Stars

### ASTRONOMY CURRICULUM Unit 1: Introduction to Astronomy

Chariho Regional School District - Science Curriculum September, 2016 ASTRONOMY CURRICULUM Unit 1: Introduction to Astronomy OVERVIEW Summary Students will be introduced to the overarching concept of astronomy.

### The Milky Way & Galaxies

The Milky Way & Galaxies The Milky Way Appears as a milky band of light across the sky A small telescope reveals that it is composed of many stars (Galileo again!) Our knowledge of the Milky Way comes

### Chapter 1 Lecture. The Cosmic Perspective Seventh Edition. A Modern View of the Universe Pearson Education, Inc.

Chapter 1 Lecture The Cosmic Perspective Seventh Edition A Modern View of the Universe Chapter Opener 1.1 The Scale of the Universe Our goals for learning: What is our place in the universe? How big is

### Lecture 25: The Cosmic Distance Scale Sections 25-1, 26-4 and Box 26-1

Lecture 25: The Cosmic Distance Scale Sections 25-1, 26-4 and Box 26-1 Key Ideas The Distance Problem Geometric Distances Trigonometric Parallaxes Luminosity Distances Standard Candles Spectroscopic Parallaxes

### Galaxies and the expansion of the Universe

Review of Chapters 14, 15, 16 Galaxies and the expansion of the Universe 5/4/2009 Habbal Astro 110-01 Review Lecture 36 1 Recap: Learning from Light How does light tell us what things are made of? Every

### outline 1. in the beginning. The Big Bang 2. galaxies -- different types 3. stars -- life cycle 4. the solar system -- sun and planets

Earth s Place in the Universe outline 1. in the beginning. The Big Bang 2. galaxies -- different types 3. stars -- life cycle 4. the solar system -- sun and planets the big bang the universe is expanding

### Star. Chapter 1: Our Place in the Universe. 1.1 A Modern View of the Universe Our goals for learning:

Chapter 1: Our Place in the Universe 1.1 A Modern View of the Universe Our goals for learning: What is our physical place in the Universe? How did we come to be? How can we know what the Universe was like

### ASTR 135 Exam 4 5/4/2015

ASTR 135 Exam 4 5/4/2015 1) The Milky Way is a a) star b) star cluster d) nebula c) galaxy e) universe 2) What distance indicator or method did Edwin Hubble use to establish the distance of the Andromeda

### 1 The Solar System. 1.1 a journey into our galaxy

1 The Solar System Though Pluto, and the far-flung depths of the Solar System, is the focus of this book, it is essential that Pluto is placed in the context of the planetary system that it inhabits our

### Coriolis Effect - the apparent curved paths of projectiles, winds, and ocean currents

Regents Earth Science Unit 5: Astronomy Models of the Universe Earliest models of the universe were based on the idea that the Sun, Moon, and planets all orbit the Earth models needed to explain how the

### Star systems like our Milky Way. Galaxies

Galaxies Star systems like our Milky Way Galaxies Contain a few thousand to tens of billions of stars,as well as varying amounts of gas and dust Large variety of shapes and sizes Gas and Dust in

### D. most intense and of longest duration C. D.

Astronomy Take Home Test Answer on a separate sheet of paper In complete sentences justify your answer Name: 1. The Moon s cycle of phases can be observed from Earth because the Moon 4. The accompanying

### Lecture Outlines. Chapter 24. Astronomy Today 8th Edition Chaisson/McMillan Pearson Education, Inc.

Lecture Outlines Chapter 24 Astronomy Today 8th Edition Chaisson/McMillan Chapter 24 Galaxies Units of Chapter 24 24.1 Hubble s Galaxy Classification 24.2 The Distribution of Galaxies in Space 24.3 Hubble

### Astronomy 1504 Section 10 Final Exam Version 1 May 6, 1999

Astronomy 1504 Section 10 Final Exam Version 1 May 6, 1999 Reminder: When I write these questions, I believe that there is one one correct answer. The questions consist of all parts a e. Read the entire

### Galaxies. Galaxy Diversity. Galaxies, AGN and Quasars. Physics 113 Goderya

Galaxies, AGN and Quasars Physics 113 Goderya Chapter(s): 16 and 17 Learning Outcomes: Galaxies Star systems like our Milky Way Contain a few thousand to tens of billions of stars. Large variety of shapes

### Lecture Outlines. Chapter 17. Astronomy Today 8th Edition Chaisson/McMillan Pearson Education, Inc.

Lecture Outlines Chapter 17 Astronomy Today 8th Edition Chaisson/McMillan Chapter 17 Measuring the Stars Units of Chapter 17 17.1 The Solar Neighborhood 17.2 Luminosity and Apparent Brightness 17.3 Stellar

### ASTRONOMY QUIZ NUMBER 11

ASTRONOMY QUIZ NUMBER. Suppose you measure the parallax of a star and find 0. arsecond. The distance to this star is A) 0 light-years B) 0 parsecs C) 0. light-year D) 0. parsec 2. A star is moving toward

### Name Period Date Earth and Space Science. Solar System Review

Name Period Date Earth and Space Science Solar System Review 1. is the spinning a planetary object on its axis. 2. is the backward motion of planets. 3. The is a unit less number between 0 and 1 that describes

### Astronomy from 4 Perspectives Bi-national Heraeus Sumer School Series for Teacher Students and Teachers

Astronomy from 4 Perspectives Bi-national Heraeus Sumer School Series for Teacher Students and Teachers I. Cosmology Prof. Dr. Andreas Just Zentrum für Astronomie Heidelberg University Cosmic Distances

### The Milky Way. Finding the Center. Milky Way Composite Photo. Finding the Center. Milky Way : A band of and a. Milky Way

The Milky Way Milky Way : A band of and a The band of light we see is really 100 billion stars Milky Way probably looks like Andromeda. Milky Way Composite Photo Milky Way Before the 1920 s, astronomers

### 24.1 Hubble s Galaxy Classification

Chapter 24 Galaxies Units of Chapter 24 24.1 Hubble s Galaxy Classification 24.2 The Distribution of Galaxies in Space 24.3 Hubble s Law 24.4 XXActive Galactic Nuclei XXRelativistic Redshifts and Look-Back

### Big Galaxies Are Rare! Cepheid Distance Measurement. Clusters of Galaxies. The Nature of Galaxies

Big Galaxies Are Rare! Potato Chip Rule: More small things than large things Big, bright spirals are easy to see, but least common Dwarf ellipticals & irregulars are most common Faint, hard to see Mostly

### Chapter 2 Discovering the Universe for Yourself

Chapter 2 Discovering the Universe for Yourself 2.1 Patterns in the Night Sky Our goals for learning: What does the universe look like from Earth? Why do stars rise and set? Why do the constellations we

### The Universe and Galaxies

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

### Chapter 1 Lecture. The Cosmic Perspective Seventh Edition. A Modern View of the Universe

Chapter 1 Lecture The Cosmic Perspective Seventh Edition A Modern View of the Universe 1.1 The Scale of the Universe Our goals for learning: What is our place in the universe? How big is the universe?

### Chapter 2 Discovering the Universe for Yourself. What does the universe look like from Earth? Constellations. 2.1 Patterns in the Night Sky

Chapter 2 Discovering the Universe for Yourself 2.1 Patterns in the Night Sky Our goals for learning: What does the universe look like from Earth? Why do stars rise and set? Why do the constellations we

### Ay 1 Lecture 2. Starting the Exploration

Ay 1 Lecture 2 Starting the Exploration 2.1 Distances and Scales Some Commonly Used Units Distance: Astronomical unit: the distance from the Earth to the Sun, 1 au = 1.496 10 13 cm ~ 1.5 10 13 cm Light

### A 103 Notes, Week 14, Kaufmann-Comins Chapter 15

NEARBY GALAXIES I. Brief History A 103 Notes, Week 14, Kaufmann-Comins Chapter 15 A. Kant B. Curtis-Shapley debate C. Distance to Andromeda II. Classification of nearby galaxies: Spirals, Ellipticals,

### UNIT 1: EARTH AND THE SOLAR SYSTEM.

UNIT 1: EARTH AND THE SOLAR SYSTEM. 1) A BRIEF HISTORY Theories of the Universe In the second century BC, the astronomer Ptolemy proposed that the Earth was the centre of the Universe, and that the Sun,

### This Week in Astronomy

Homework #8 Due Wednesday, April 18, 11:59PM Covers Chapters 15 and 16 Estimated time to complete: 40 minutes Read chapters, review notes before starting This Week in Astronomy Credit: NASA/JPL-Caltech

### Beyond Our Solar System Chapter 24

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

### Observational Astronomy - Lecture 4 Orbits, Motions, Kepler s and Newton s Laws

Observational Astronomy - Lecture 4 Orbits, Motions, Kepler s and Newton s Laws Craig Lage New York University - Department of Physics craig.lage@nyu.edu February 24, 2014 1 / 21 Tycho Brahe s Equatorial

### Name Regents Review Packet #2 Date

Name Regents Review Packet #2 Date Base your answers to questions 1 through 5 on diagram below, which represents the Sun s apparent paths and the solar noon positions for an observer at 42 N latitude on

### Astronomy AST-1002 Section 0459 Discover the Universe Fall 2017

Astronomy AST-1002 Section 0459 Discover the Universe Fall 2017 Instructor: Dr. Francisco Reyes Web Page: http://www.astro.ufl.edu/~freyes/classes/ast1002/index.htm Textbook: Astronomy: A Beginners Guide

### CHAPTER 28 STARS AND GALAXIES

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:

### 1. The Moon appears larger when it rises than when it is high in the sky because

2-1 Copyright 2016 All rights reserved. No reproduction or distribution without the prior written consent of 1. The Moon appears larger when it rises than when it is high in the sky because A. you are

### The Cosmological Redshift. Cepheid Variables. Hubble s Diagram

SOME NEGATIVE EFFECTS OF THE EXPANSION OF THE UNIVERSE. Lecture 22 Hubble s Law and the Large Scale Structure of the Universe PRS: According to modern ideas and observations, what can be said about the

### Modern Astronomy Review #1

Modern Astronomy Review #1 1. The red-shift of light from distant galaxies provides evidence that the universe is (1) shrinking, only (3) shrinking and expanding in a cyclic pattern (2) expanding, only

### Chapter 9: Measuring the Stars

Chapter 9: Measuring the Stars About 10 11 (100,000,000,000) stars in a galaxy; also about 10 11 galaxies in the universe Stars have various major characteristics, the majority of which fall into several

### Chapter 2 Lecture. The Cosmic Perspective Seventh Edition. Discovering the Universe for Yourself

Chapter 2 Lecture The Cosmic Perspective Seventh Edition Discovering the Universe for Yourself Discovering the Universe for Yourself 2.1 Patterns in the Night Sky Our goals for learning: What does the

### Astronomy A BEGINNER S GUIDE TO THE UNIVERSE EIGHTH EDITION

Astronomy A BEGINNER S GUIDE TO THE UNIVERSE EIGHTH EDITION CHAPTER 14 The Milky Way Galaxy Lecture Presentation 14.0 the Milky Way galaxy How do we know the Milky Way exists? We can see it even though

### Galaxies and Cosmology

Galaxies and Cosmology Attendance Quiz Are you here today? (a) yes (b) no Here! (c) Cosmetology? Like hair and nails and makeup? Next Tuesday, 5/30: Dr. Jorge Moreno is unavailable, so class will be cancelled

### Welcome Aboard!! CHANGE OF KOMATSU S OFFICE HOURS. Briefing Welcome to the Cosmic Tour: Some Guide Lines. Lecture 1 Our Place in the Universe

CHANGE OF KOMATSU S OFFICE HOURS (Previous) Tuesdays & Thursdays 3:30 to 4:30 (New) Tuesdays 4:45 to 5:30 Thursdays 3:30 to 4:30 YOURNAME 31AUG Welcome Aboard!! AUSTIN AST 301 YOURNAME 31AUG 2.5 MILLION

### Announcements. Lecture 11 Properties of Stars. App Bright = L / 4!d 2

Announcements Quiz#3 today at the end of 60min lecture. Homework#3 will be handed out on Thursday. Due October 14 (next Thursday) Review of Mid-term exam will be handed out next Tuesday. Mid-term exam

### Size of the Earth and the Distances to the Moon and the Sun

Size of the Earth and the Distances to the Moon and the Sun Objectives Using observations of the Earth-Moon-Sun system and elementary geometry and trigonometry, we will duplicate the methods of the ancient

### Johannes Kepler ( ) German Mathematician and Astronomer Passionately convinced of the rightness of the Copernican view. Set out to prove it!

Johannes Kepler (1571-1630) German Mathematician and Astronomer Passionately convinced of the rightness of the Copernican view. Set out to prove it! Kepler s Life Work Kepler sought a unifying principle

### Chapter 1 Review Clickers. The Cosmic Perspective Seventh Edition. A Modern View of the Universe Pearson Education, Inc.

Review Clickers The Cosmic Perspective Seventh Edition A Modern View of the Universe Put these objects in the correct order, from nearest to farthest from Earth: a) The Moon, Mars, the Sun, the nearest

### Dive into Saturn.

Dive into Saturn http://www.pbs.org/wgbh/nova/space/death-dive-to-saturn.html Read Ch. 3 By next class time Do practice online quiz 01 Axis tilt changes directness of sunlight during the year. Why Does

### Ast ch 4-5 practice Test Multiple Choice

Ast ch 4-5 practice Test Multiple Choice 1. The distance from Alexandria to Syene is about 500 miles. On the summer solstice the sun is directly overhead at noon in Syene. At Alexandria on the summer solstice,

### Tycho Brahe

Tycho Brahe 1546-1601 At the time of Shakespeare and Elizabeth I and Champlain Lost part of his nose in a duel over who was the best mathematician At 27 he measured the distance of a supernova and a comet

### The Scale of the Cosmos

The Scale of the Cosmos Scale defined as relative magnitude. Astronomy deals with objects on a vast range of size scales and time scales. Most of these size and time scales are way beyond our every-day

### The Scale of the Cosmos

The Scale of the Cosmos Scale defined as relative magnitude. Astronomy deals with objects on a vast range of size scales and time scales. Most of these size and time scales are way beyond our every-day

### 29:50 Stars, Galaxies, and the Universe Final Exam December 13, 2010 Form A

29:50 Stars, Galaxies, and the Universe Final Exam December 13, 2010 Form A There are 40 questions. Read each question and all of the choices before choosing. Budget your time. No whining. Walk with Ursus!

### V. M. Slipher ( ) was an astronomer who worked at Lowell Observatory in Flagstaff, Arizona. In 1909 he began studying the spectrum of the

Hubble s Law V. M. Slipher (1875-1969) was an astronomer who worked at Lowell Observatory in Flagstaff, Arizona. In 1909 he began studying the spectrum of the Andromeda Nebula. He found that that object

### Stellar Composition. How do we determine what a star is made of?

Stars Essential Questions What are stars? What is the apparent visual magnitude of a star? How do we locate stars? How are star classified? How has the telescope changed our understanding of stars? What

### Exam #1 Covers material from first day of class, all the way through Tides and Nature of Light Supporting reading chapters 1-5 Some questions are

Exam #1 Covers material from first day of class, all the way through Tides and Nature of Light Supporting reading chapters 1-5 Some questions are concept questions, some involve working with equations,

### Chapter 1 Our Place in the Universe

Chapter 1 Our Place in the Universe 1.1 Our Modern View of the Universe Topics we will explore: What is our place in the universe? How did we come to be? How can we know what the universe was like in the

### Review of previous concepts!! Earth s orbit: Year, seasons, observed constellations, Polaris (North star), day/night lengths, equinoxes

Review of previous concepts!! Earth s orbit: Year, seasons, observed constellations, Polaris (North star), day/night lengths, equinoxes Celestial poles, celestial equator, ecliptic, ecliptic plane (Fig

### AST 2010: Descriptive Astronomy EXAM 2 March 3, 2014

AST 2010: Descriptive Astronomy EXAM 2 March 3, 2014 DO NOT open the exam until instructed to. Please read through the instructions below and fill out your details on the Scantron form. Instructions 1.

### USAAAO First Round 2015

USAAAO First Round 2015 This round consists of 30 multiple-choice problems to be completed in 75 minutes. You may only use a scientific calculator and a table of constants during the test. The top 50%

### Set 5: Expansion of the Universe

Set 5: Expansion of the Universe Cosmology Study of the origin, contents and evolution of the universe as a whole Expansion rate and history Space-time geometry Energy density composition Origin of structure

### Galaxies Galore. Types of Galaxies: Star Clusters. Spiral spinning wit arms Elliptical roundish Irregular no set pattern

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

### Geoscience Astronomy Formative on Stellar Evolution and Galaxies

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

### Chapter 8: The Family of Stars

Chapter 8: The Family of Stars Motivation We already know how to determine a star s surface temperature chemical composition surface density In this chapter, we will learn how we can determine its distance

### Astronomy 110 Lecture Fall, 2005 Astronomy 110 1

Astronomy 110 Lecture 5 + 6 Fall, 2005 Astronomy 110 1 Planets Known in Ancient Times Mercury difficult to see; always close to Sun in sky Venus very bright when visible morning or evening star Mars noticeably

### 80 2 Observational Cosmology L and the mean energy

80 2 Observational Cosmology fluctuations, short-wavelength modes have amplitudes that are suppressed because these modes oscillated as acoustic waves during the radiation epoch whereas the amplitude of

### Extra-Curricular Activity GCSE Astronomy 2 Year Course (1 hour per week)

SEPTEMBER OCTOBER NOVEMBER DECEMBER Extra-Curricular Activity GCSE Astronomy 2 Year Course (1 hour per week) Introduction to the course Revision of:- A day and a year The link between tilt of the Earth

### Planets in the Sky ASTR 101 2/16/2018

Planets in the Sky ASTR 101 2/16/2018 1 Planets in the Sky 2018 paths of Jupiter among stars (2017/2018) Unlike stars which have fixed positions in the sky (celestial sphere), planets seem to move with

### PHYS 155 Introductory Astronomy

PHYS 155 Introductory Astronomy - observing sessions: Sunday Thursday, 9pm, weather permitting http://www.phys.uconn.edu/observatory - Exam - Tuesday March 20, - Review Monday 6:30-9pm, PB 38 Marek Krasnansky

### Determining distance. L 4π f. d = d = R θ. Standard candle. Standard ruler

Determining distance Standard candle d = L 4π f 1 2 d L Standard ruler d = R θ θ R Determining distance: Parallax RULER tanπ = R d π R d π R = 1AU = 1.5 10 13 cm Define new distance unit: parsec (parallax-second)

### 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.

### 1. Galaxy (a) the length of a planet s day. 2. Rotational Period (b) dust and gases floating in space

Vocabulary: Match the vocabulary terms on the left with the definitions on the right 1. Galaxy (a) the length of a planet s day 2. Rotational Period (b) dust and gases floating in space 3. Orbital Period

### Lecture Outlines. Chapter 15. Astronomy Today 8th Edition Chaisson/McMillan Pearson Education, Inc.

Lecture Outlines Chapter 15 Astronomy Today 8th Edition Chaisson/McMillan Chapter 15 Exoplanets Units of Chapter 15 15.1 Modeling Planet Formation 15.2 Solar System Regularities and Irregularities 15.3

### The Scientific Method, or How Big is the Sun?

The Scientific Method, or How Big is the Sun? Learning Objectives! What is empiricism? What is objectivity?! What are the main principles of the scientific method? What is Occam s Razor?! Why do the principles

### Lecture 26 The Hertzsprung- Russell Diagram January 13b, 2014

1 Lecture 26 The Hertzsprung- Russell Diagram January 13b, 2014 2 Hertzsprung-Russell Diagram Hertzsprung and Russell found a correlation between luminosity and spectral type (temperature) 10000 Hot, bright

### Astronomy. The Nature of Stars

Astronomy A. Dayle Hancock adhancock@wm.edu Small 239 Office hours: MTWR 10-11am The Nature of Stars Distances to stars A Star's brightness and Luminosity A Magnitude scale Color indicates a Star's temperature

### Our Universe: Creation, Galaxies, Stars and Celestial Objects

Our Universe: Creation, Galaxies, Stars and Celestial Objects Big Bang Theory Our universe began with one huge exploding atom that relapsed all the energy and matter that exists in the universe today.

### Class Notes: Astronomy

Name: Date: Period: Astronomy The Physical Setting: Earth Science Class Notes: Astronomy I. Apparent Motion Geocentric Universe -! Starts all rotate around the Earth on a single sphere at º/hour Planets

### PSSC: The Earth Sciences

PSSC: The Earth Sciences Dr. Neil Suits, Assistant Professor of Earth Science Office: Sci 118 Phone: 896 5931 neil.suits@msubillings.edu Best times to see me are right after class on Mondays and Fridays

### Today in Astronomy 328: binary stars

Today in Astronomy 38: binary stars Binary-star systems. Direct measurements of stellar mass and radius in eclipsing binary-star systems. At right: two young binary star systems in the Taurus star-forming

### The Stars. Chapter 14

The Stars Chapter 14 Great Idea: The Sun and other stars use nuclear fusion reactions to convert mass into energy. Eventually, when a star s nuclear fuel is depleted, the star must burn out. Chapter Outline