# CALCULATING DISTANCES. Cepheids and RR Lyrae India Jackson-Henry

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 CALCULATING DISTANCES Cepheids and RR Lyrae India Jackson-Henry

2 What are Cepheids and RR Lyrae Stars As stars evolve, their atmospheres become unstable and the star becomes intrinsically variable. Two special classes of variable stars are used to determine distances within our galaxy and distances to neighboring galaxies. Cepheid variables have periods that range from a few days to a few hundred days. They are evolved Population I stars and lie within the spiral arms of a galaxy. RR Lyrae stars (named after the prototype star RR in the constellation Lyra) are evolved population II stars and can be seen in the halos of galaxies, especially in globular clusters. Periods of RR Lyrae stars are typically 0.5 to 1 day, making it possible to see one or more periods in a single night of observations.

3

4 Henrietta Leavitt Leavitt: found a relationship between period and luminosity (apparent magnitude) in cepheid variables in LMC. Since all the stars are in the LMC, and are at the same distance from us, the apparent magnitudes are an accurate measure of the true relative luminosities of the stars.

5 Hubble Used Cepheids as standard candles Was the first to measure distances to spiral nebulae Found that a galaxy's redshift and distance are related! = # \$ %

6 Why not just uses parallax? The only directly measurable distances in astronomy are those made by trigonometric parallax such as stars on the main sequence. However, Cepheids are not main sequence stars. Once you get to a certain distance the parallax technique is null. Some galactic Cepheids are found in clusters of stars. Like the stars in the LMC, all the stars in these clusters are at the same distance from us. One can use the spectroscopic parallax of the main sequence stars in the cluster to determine the distance to the cluster, and the Cepheid. The distance and observed magnitude then directly give the luminosity of the Cepheid, and a calibration of the period-luminosity relation.

7 Basic Technique Determine the period, and observe the mean magnitude m. Find the absolute magnitude M that corresponds to that period:! " = 2.76 )*+, **Hubble Space Telescope:! / = 2.43 ± 0.12 )*+, 1 (4.05 ± 0.02) The difference between the apparent and absolute magnitudes, m-m, known as the distance modulus, is equal to 5 log(d) -5, where the distance is in parsecs: 6! = 5 log : 5 6! + 5 = 5 log : 6! + 5 = log : 5 : = 10 A

8 Examples & Range of Relevant Distances!"# 6822: ( = 10,-./0 0 = /0 0 = :

9 Potential Problems There are of course many complications, most of which are beyond the scope of this introduction. However, there is one very important caveat. The galactic calibration of the Cepheids is inapplicable to the LMC Cepheids. This is because there is a large difference in mean metallicity between the two galaxies: stars in the LMC are metal-deficient relative to our Galaxy. This affects the opacity, and the periods. Population I consists of metal-rich stars, including the Sun. Population II is metal poor, representing a population of stars that formed from a less enriched interstellar medium. At a given period, W Vir stars are less luminous than are classical Cepheids. Inadvertent application of the classical Cepheid P-L relation to W Vir stars leads to a to a large overestimate of the distances.

10 Recent Results The Next Generation Virgo Cluster Survey (NGVS). XVIII. Measurement and Calibration of Surface Brightness Fluctuation Distances for Bright Galaxies in Virgo (and Beyond) Michele Cantiello, Published 2018 March The American Astronomical Society Hubble Space Telescope Trigonometric Parallax of Polaris B, Companion of the Nearest Cepheid *. Howard E. Bond 1,2,6, Edmund P. Nelan 2, Nancy Remage Evans 3, Gail H. Schaefer 4, and Dianne Harmer 5 P.2018 January 23

11 References Benedict, G. Fritz; (2002). "Astrometry with the Hubble Space Telescope: A Parallax of the Fundamental Distance Calibrator δ Cephei". The Astronomical Journal. 124(3): Periods of 25 Variable Stars in the Small Magellanic Cloud, Harvard College Observatory Circular 173, 1912, Edward C. Pickering

### 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

### 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,

### 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

### 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

### Galaxies. Lecture Topics. Lecture 23. Discovering Galaxies. Galaxy properties. Local Group. History Cepheid variable stars. Classifying galaxies

Galaxies Lecture 23 APOD: NGC 3628 (The Hamburger Galaxy) 1 Lecture Topics Discovering Galaxies History Cepheid variable stars Galaxy properties Classifying galaxies Local Group 2 23-1 Discovering Galaxies

### 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

### The Milky Way Galaxy Guiding Questions

The Milky Way Galaxy Guiding Questions 1. What is our Galaxy? How do astronomers know where we are located within it? 2. What is the shape and size of our Galaxy? 3. How do we know that our Galaxy has

### The Milky Way Galaxy

The Milky Way Galaxy Guiding Questions 1. What is our Galaxy? How do astronomers know where we are located within it? 2. What is the shape and size of our Galaxy? 3. How do we know that our Galaxy has

### Astro 1050 Fri. Apr. 14, 2017

Astro 1050 Fri. Apr. 14, 2017 Today: Ch. 19: Our Galaxy, the Milky Way Reading in Bennett: Ch 12 this week, Ch. 13 for next week 1 2 Chapter 12 The Milky Way Galaxy Band of light running around sky in

### Hubble Ultra Deep Space View

Galaxies stars come in large groups (20-1000 billion stars) called Galaxies >2 trillion observable galaxies. Come in Shapes and Sizes depending on how they were formed Elliptical (football shape) Spirals

### 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

### 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.

### Chapter 23 The Milky Way Galaxy Pearson Education, Inc.

Chapter 23 The Milky Way Galaxy The Milky Way is our own galaxy viewed from the inside. It is a vast collection of more than 200 billion stars, planets, nebulae, clusters, dust and gas. Our own sun and

### 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

### Hubble Ultra Deep Space View PHYS 162 2

Galaxies stars come in large groups (20-200 billion stars) called Galaxies >2 trillion observable galaxies. Come in Shapes and Sizes depending on how they were formed Elliptical (football shape) Spirals

### 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

### 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

### 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!

### 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

### 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

### 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

### 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 20 Lecture. The Cosmic Perspective Seventh Edition. Galaxies and the Foundation of Modern Cosmology Pearson Education, Inc.

Chapter 20 Lecture The Cosmic Perspective Seventh Edition Galaxies and the Foundation of Modern Cosmology Galaxies and the Foundation of Modern Cosmology 20.1 Islands of Stars Our goals for learning: How

### Earth-based parallax measurements have led to the conclusion that the Pleiades star cluster is about 435 light-years from Earth.

1 The Pleiades star cluster is a prominent sight in the night sky. All the stars in the cluster were formed from the same gas cloud. Hence the stars have nearly identical ages and compositions, but vary

### A100 Exploring the Universe: Discovering Galaxies. Martin D. Weinberg UMass Astronomy

A100 Exploring the Universe: Discovering Martin D. Weinberg UMass Astronomy astron100-mdw@courses.umass.edu November 13, 2014 Read: Chaps 19, 20 11/13/14 slide 1 ! and Elliptical Irregular : summary Exam

### Measuring the Hubble Constant through Cepheid Distances

Measuring the Hubble Constant through Cepheid Distances Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant Freedman, Madore, Gibson, et al., Astrophysical Journal

### 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

### Exam # 3 Tue 12/06/2011 Astronomy 100/190Y Exploring the Universe Fall 11 Instructor: Daniela Calzetti

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

### Observations of Pulsating Stars

Observations of Pulsating Stars Noel Richardson April 15, 2008 1 Introduction Pulsating stars are stars that show some sort of instability, often which can be called vibration or oscillation just as easily

### 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

### MEASURING DISTANCE WITH CEPHEID VARIABLES

Name Date Partner(s) Grade / MEASURING DISTANCE WITH CEPHEID VARIABLES Written by T. Jaeger INTRODUCTION Cepheid stars (named after the class prototype star, DELTA CEPHEI) are of great interest because

### 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

### 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

### Ay162, Spring 2006 Week 8 p. 1 of 15

Astronomy 162, Week 8 Milky Way Galaxy, continued Patrick S. Osmer Spring, 2006 Rotation of Galaxy How do we know the galaxy is rotating, and how do we measure its rotation? Measure radial velocities of

### BROCK UNIVERSITY. Test 2, March 2015 Number of pages: 9 Course: ASTR 1P02 Number of Students: 420 Date of Examination: March 5, 2015

BROCK UNIVERSITY Page 1 of 9 Test 2, March 2015 Number of pages: 9 Course: ASTR 1P02 Number of Students: 420 Date of Examination: March 5, 2015 Number of hours: 50 min Time of Examination: 18:00 18:50

### Oases in the Dark: Galaxies as probes of the Cosmos

Utah State University DigitalCommons@USU Public Talks Astrophysics 8-10-2007 Oases in the Dark: Galaxies as probes of the Cosmos Shane L. Larson Utah State University Follow this and additional works at:

### Doppler Shift/Effect of EM Waves

Doppler Shift/Effect of EM Waves A quick and dirty intro Not quite the same as Doppler shift of sounds (acoustic waves) but has similar physical principles Ø Speed of emitting source changes the wavelength/frequency

### The Milky Way Galaxy. sun. Examples of three Milky-Way like Galaxies

The Milky Way Galaxy sun This is what our Galaxy would look like if we were looking at it from another galaxy. Examples of three Milky-Way like Galaxies 1. Roughly 100,000 light years across 2. Roughly

### Universe. Chapter 19. Stellar Evolution: On and After the Main Sequence 8/13/2015. By reading this chapter, you will learn

Roger Freedman Robert Geller William Kaufmann III Universe Tenth Edition Chapter 19 Stellar Evolution: On and After the Main Sequence By reading this chapter, you will learn 19 1 How a main sequence star

### 6. Star Colors and the Hertzsprung-Russell Diagram

In addition to its brightness, light in general is characterized by its color. 6. Star Colors and the Hertzsprung-Russell Diagram http://apod.nasa.gov/apod/ Depending on the temperature of the matter at

### 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

### Tour of Galaxies. Sgr A* VLT in IR + adaptive optics. orbits. ASTR 1040 Accel Astro: Stars & Galaxies VLT IR+AO

ASTR 1040 Accel Astro: Stars & Galaxies Prof. Juri Toomre TA: Kyle Augustson Lecture 23 Tues 8 Apr 08 zeus.colorado.edu/astr1040-toomre toomre Tour of Galaxies Briefly revisit Monster in the Milky Way

### Einführung in die Astronomie II

Einführung in die Astronomie II Teil 12 Peter Hauschildt yeti@hs.uni-hamburg.de Hamburger Sternwarte Gojenbergsweg 112 21029 Hamburg 13. September 2017 1 / 77 Overview part 12 The Galaxy Historical Overview

### 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

### The Milky Way. Overview: Number of Stars Mass Shape Size Age Sun s location. First ideas about MW structure. Wide-angle photo of the Milky Way

Figure 70.01 The Milky Way Wide-angle photo of the Milky Way Overview: Number of Stars Mass Shape Size Age Sun s location First ideas about MW structure Figure 70.03 Shapely (~1900): The system of globular

### Part two of a year-long introduction to astrophysics:

ASTR 3830 Astrophysics 2 - Galactic and Extragalactic Phil Armitage office: JILA tower A909 email: pja@jilau1.colorado.edu Spitzer Space telescope image of M81 Part two of a year-long introduction to astrophysics:

### Types of Stars and the HR diagram

Types of Stars and the HR diagram Full window version (looks a little nicer). Click button to get back to small framed version with content indexes. This material (and images) is copyrighted! See

### Surveying the Milky Way

Surveying the Milky Way How Astronomers Prepared a Detailed Map of the Nearby Regions of Space By the 1920 s Primary References: Astronomy:The Evolving Universe, Michael Zeilik, Second Edition, Harper

### Measuring Distances. Taking the Measure of the Universe

Measuring Distances Taking the Measure of the Universe The Importance of Distance We talked about how the brightness of a star can be due to 2 effects: distance or luminosity. Without a direct measurement

### Chapter 15 Reading Quiz Clickers. The Cosmic Perspective Seventh Edition. Surveying the Stars Pearson Education, Inc.

Reading Quiz Clickers The Cosmic Perspective Seventh Edition Surveying the Stars 15.1 Properties of Stars How do we measure stellar luminosities? How do we measure stellar temperatures? How do we measure

### ASTR 200 : Lecture 27. Expansion and large scale structure

ASTR 200 : Lecture 27 Expansion and large scale structure 1 A preference for recession In 1912, american astronomer Vesto Slipher began painstakingly acquiring spectra of `spiral nebulae' and was the first

### Module 3: Astronomy The Universe Topic 2 Content: The Milky Way Galaxy Presentation Notes

On a clear night, you can go outside and view the Moon and the stars scattered throughout the night sky. At times, you can also see neighboring planets. When you look at the sky and these objects, almost

### The physical properties of galaxies in Universe

The physical properties of galaxies in Universe Iurii Babyk, Dublin Institute for Advanced Studies, Dublin City University, Main Astronomical Observatory of the NAS of Ukraine. Introduction Large-Scale

### 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

### Astronomical Distance Determination

Distance ladder: Determine distances, d 1, for a nearby set of objects using technique 1, but then Astronomical Distance Determination http://apod.nasa.gov/apod/ Find new brighter objects at distances

### Interferometry and the Cepheid Distance Scale

256 Interferometry and the Cepheid Distance Scale Thomas G. Barnes, III 82 Mt. Locke Road, McDonald Observatory, TX 79734; tgb@astro.as.utexas.edu Presented at the 100th Spring Meeting of the AAVSO, May

### 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

### 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:

### Galaxies Galaxy Classification Formation of Galaxies Galactic Evolution

Class 1 Introduction, Background History of Modern Astronomy The Night Sky, Eclipses and the Seasons Kepler's Laws Newtonian Gravity General Relativity Matter and Light Telescopes Class 2 Solar System

### Number of Stars: 100 billion (10 11 ) Mass : 5 x Solar masses. Size of Disk: 100,000 Light Years (30 kpc)

THE MILKY WAY GALAXY Type: Spiral galaxy composed of a highly flattened disk and a central elliptical bulge. The disk is about 100,000 light years (30kpc) in diameter. The term spiral arises from the external

### Figure 19.19: HST photo called Hubble Deep Field.

19.3 Galaxies and the Universe Early civilizations thought that Earth was the center of the universe. In the sixteenth century, we became aware that Earth is a small planet orbiting a medium-sized star.

### Lecture 25 The Milky Way Galaxy November 29, 2017

Lecture 25 The Milky Way Galaxy November 29, 2017 1 2 Size of the Universe The Milky Way galaxy is very much larger than the solar system Powers of Ten interactive applet 3 Galaxies Large collections of

### 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)

### Question 1. Question 2. Correct. Chapter 16 Homework. Part A

Chapter 16 Homework Due: 11:59pm on Thursday, November 17, 2016 To understand how points are awarded, read the Grading Policy for this assignment. Question 1 Following are a number of distinguishing characteristics

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

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 james.lattimer@stonybrook.edu Distances in

### 6. Star Colors and the Hertzsprung-Russell Diagram

6. Star Colors and the Hertzsprung-Russell Diagram http://apod.nasa.gov/apod/ Supernovae Type Ia in M82 January 22, 2014 Still rising may go to m = 8 (or 10?) What we can learn about stars from their light:

### 6. Star Colors and the Hertzsprung-Russell Diagram.

6. Star Colors and the Hertzsprung-Russell Diagram http://apod.nasa.gov/apod/ Supernovae Type Ia in M82 January 22, 2014 Still rising may go to m = 8 (or 10?) What we can learn about stars from their light:

### Hie-Joon Kim. Professor Emeritus Seoul National University. Experience. Representative Publications

Hie-Joon Kim Professor Emeritus Seoul National University B.S. Chemistry, Seoul National University, Korea, 1970 Ph.D. Chemistry, University of Chicago, USA, 1977 Experience Professor, Department of Chemistry

### Pulsation in RR Lyrae stars

University of Portsmouth Final year project Pulsation in RR Lyrae stars Composer: Jonathan Harrie Supervisor: Michael McCabe Abstract The fact that RR Lyrae are known to serve as good standard candles

### The Curtis-Shapley Debate: Refining Galactic Models and Our Place in the Universe

The Curtis-Shapley Debate: Refining Galactic Models and Our Place in the Universe Richard McDonald, student number 2798107 Swinburne Astronomy Online HET-603 (B) Introduction The beginning of the 20 th

### Galaxies: Island Universes in the Cosmos

Utah State University DigitalCommons@USU Colloquia and Seminars Astrophysics 2-9-2011 Galaxies: Island Universes in the Cosmos Shane L. Larson Utah State University Follow this and additional works at:

### Cepheid Stars as standard candles for distance measurements

Cepheid Stars as standard candles for distance measurements Philipp Engelmann (Jena) Cepheids are an essential tool for distance measurements in our galactic neighbourhood. This report provides a general

### Chapter 15 The Milky Way Galaxy

Chapter 15 The Milky Way Galaxy Guidepost This chapter plays three parts in our cosmic drama. First, it introduces the concept of a galaxy. Second, it discusses our home, the Milky Way Galaxy, a natural

### Our View of the Milky Way. 23. The Milky Way Galaxy

23. The Milky Way Galaxy The Sun s location in the Milky Way galaxy Nonvisible Milky Way galaxy observations The Milky Way has spiral arms Dark matter in the Milky Way galaxy Density waves produce spiral

### 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

### Telescopes and estimating the distances to astronomical objects

Telescopes and estimating the distances to astronomical objects Why do we use telescopes? 1. Light-collecting area: A telescope is a light bucket Q: How much more light can a telescope with a diameter

### Classification Distribution in Space Galaxy Clusters. Formation and Evolution Hubble s Law

The American astronomer Edwin Hubble in 1924, according to appearance of galaxies categorized them into four basic types. Classification Distribution in Space Galaxy Clusters Masses Formation and Evolution

### Hubble s Law and the Cosmic Distance Scale

Lab 7 Hubble s Law and the Cosmic Distance Scale 7.1 Overview Exercise seven is our first extragalactic exercise, highlighting the immense scale of the Universe. It addresses the challenge of determining

### Atlantis Challenger Columbia. Discovery Endeavour Enterprise

T1 T2 T3 T4 T5 SCORE: 150 / 150 + Bonus 2 KEY: Alternative, acceptable answers are given in brackets Bonus: Name NASA s 6 space shuttles 1 bonus point per 3 correct answers. (2 pts total) Atlantis Challenger

### 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

### Astronomical Distance Determination

Astronomical Distance Determination http://apod.nasa.gov/apod/ For relatively nearby sources, one can measure distances by surveying - by measuring the very small angles that a star s position is displaced

### It is about 100,000 ly across, 2,000 ly thick, and our solar system is located 26,000 ly away from the center of the galaxy.

The Galaxies The Milky Way Galaxy Is a spiral galaxy in which our solar system is located. The center of the galaxy lies in the Sagittarius Constellation. It is about 100,000 ly across, 2,000 ly thick,

### Notes for Wednesday, July 16; Sample questions start on page 2 7/16/2008

Notes for Wednesday, July 16; Sample questions start on page 2 7/16/2008 Wed, July 16 MW galaxy, then review. Start with ECP3Ch14 2 through 8 Then Ch23 # 8 & Ch 19 # 27 & 28 Allowed Harlow Shapely to locate

### Reminders! Observing Projects: Both due Monday. They will NOT be accepted late!!!

Reminders! Website: http://starsarestellar.blogspot.com/ Lectures 1-15 are available for download as study aids. Reading: You should have Chapters 1-14 read. Read Chapters 15-17 by the end of the week.

### 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,

### National Aeronautics and Space Administration. Glos. Glossary. of Astronomy. Terms. Related to Galaxies

National Aeronautics and Space Administration Glos of Astronomy Glossary Terms Related to Galaxies Asterism: A pattern formed by stars not recognized as one of the official 88 constellations. Examples

### Problem Set 3, AKA First midterm review Astrophysics 4302 Due Date: Sep. 23, 2013

Problem Set 3, AKA First midterm review Astrophysics 4302 Due Date: Sep. 23, 2013 1. δ Cephei is a fundamental distance scale calibrator. It is a Cepheid with a period of 5.4 days. A campaign with the

### The Distances and Ages of Star Clusters

Name: Partner(s): Lab #7 The Distances and Ages of Star Clusters 0.1 Due July 14th Very few stars are born isolated. Instead, most stars form in small groups, known as clusters. The stars in a cluster

### Universe. If you could see it from afar. Chapter 22. Our Galaxy 8/17/2015. By reading this chapter, you will learn. Tenth Edition

Roger Freedman Robert Geller William Kaufmann III Universe Tenth Edition Chapter 22 Our Galaxy By reading this chapter, you will learn 22 1 How astronomers discovered the solar system s location within

### The Hertzsprung-Russell Diagram and Stellar Evolution

The Hertzsprung-Russell Diagram and Stellar Evolution Names: The H-R Diagram and Stellar Properties Activity 1. In which corner of the diagram (upper right, upper left, lower right, or lower left) would

### Science Olympiad Astronomy C Division Event National Exam

Science Olympiad Astronomy C Division Event National Exam University of Central Florida May 17, 2014 Team Number: Team Name: Instructions: 1) Please turn in all materials at the end of the event. 2) Do

### Unit 16: Astronomy and space science. Learning aim A Understand the fundamental aspects of the solar system

Unit 16: Astronomy and space science Learning aim A Understand the fundamental aspects of the solar system Contents page Note: anywhere you see a capital D means you MUST draw a diagram. Radiative zone

### Jason Kalirai (STScI)

Jason Kalirai (STScI) Outline An Introduction: The First Hints on How Stars Evolve. Our Current Picture of Stellar Evolution A Surprise in our Backyard: The First Discovered White Dwarf Why Search for

### Supernovae and cosmology

Supernovae and cosmology Gavin Lawes Wayne State University David Cinabro Wayne State University Johanna-Laina Fischer Outline Structure of the universe Dynamics of the universe Type 1a supernova Michigan

### Alternative to Dark Energy

National National Aeronautics Aeronautics and and Space Space Administration Administration Alternative to Dark Energy Space Weather by John T. Clarke Taken from: Hubble 2010: Science Year in Review TakenProduced

### Globular and Open Clusters in our Galaxy

Globular and Open Clusters in our Galaxy Introduction By looking at the sky in a clear moonless night through a small telescope or even casual binoculars, it comes out myriads of stars that were not previously

### 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