Each star is born with a specific mass. This mass is the main factor in determining the star s brightness, temperature, expected lifetime, type of
|
|
- Marjory Underwood
- 5 years ago
- Views:
Transcription
1 Each star is born with a specific mass. This mass is the main factor in determining the star s brightness, temperature, expected lifetime, type of death, and spectra. Stars are classified according to their spectra.
2 Properties of Stars Mass The single most important property that determines other properties of the star. Luminosity The total amount of energy (light) that a star emits into space. Temperature surface temperature, closely related to the luminosity and color of the star. Spectral type closely related to the surface temperature Size together with temperature determine the luminosity
3 What can we measure directly? The Easy Ones: Apparent brightness: a well-calibrated detector. Temperature: spectroscopy Spectral type: spectroscopy The Hard ones: Distance: stellar parallax, but the stars are so farrrrr away Size: The stars are so far away. Their small angular size makes it really difficult to be measured directly. Mass: Newton s version of Kepler s Third Law Need to find the right targets
4 The Apparent Brightness Apparent brightness The brightness of the a star as it appears to our eyes (or detectors). It depends on both the luminosity AND distance between the star and the Earth. The apparent brightness of a star is related to its luminosity and distance by the formula: apparent brightness luminosity 4π (distance) 2 The total energy in this cone is fixed At a larger distance from the star, the same amount of energy is spread into a larger area. Thus, the apparent brightness of a star is lower if we are
5 Astronomers realized that large numbers of stars exhibit a small number of distinct patterns in their spectral features.
6 Spectral lines are caused by different elements present in a star. The overall spectrum is strongly related to the surface temperature of the star. Stars are then categorized into classes distinguished by the strength of the spectral lines and their shape.
7 The 7 classes of stars are: O B A F G K M From O M: Stars decrease in temperature Stars generally become less massive (smaller)
8 O B A F G K M Oh Be A Fine Guy/Girl, Kiss Me! One Bug Ate Five Green Killer Moths These are two of many mnemonic devices students and astronomers use to remember the proper order of stellar classification; from the hottest blue stars (O-type) to the coldest red stars (M-type).
9 For analysis purposes, stars are placed on the H-R diagram according to their luminosity and their temperature (Spectral Class).
10 The Hertsprung-Russell or H-R diagram reveals that about 90% of all stars lie along a smooth diagonal curve called the main sequence with hot, luminous stars in the upper left and cool, dim stars in the lower right. Not all stars fall on the main sequence. Stars below the main sequence are called white dwarfs and those above it are called giants.
11 Since hotter stars are bluer, and cooler stars are redder, a White Dwarf is hotter than a Red Giant.
12 HR Diagram in Luminosity vs Temperature
13 Hertzsprung- Russell Diagram Sizes scale 1 R sun 10 R sun 100 R sun 1000 R sun Notice that Temperature scale decreases from left to right. The scale of luminosity is in power of 10 (log scale). Mass increases from lower right to upper left Size increases from lower left to upper right.
14 Classification of Stars in H-R Diagram 1. The Main Sequence stars healthy stars, fusing hydrogen in the core. High-mass, high-luminosity, high-temperature, and shortlived stars on the upper-lefthand corner Low-mass, low-luminosity, low-temperature, and longlived stars on the lower-righthand corner 2. The Supergiants, 3. The Giants, Supergiants and giants are dying stars, fusing helium and heavier elements. 4. The White Dwarfs. dead stars, exposed core of dead main-sequence stars. Sizes scale 1 R sun 10 R sun 100 R sun 1000 R sun
15
16 Color: blue Temperature: 28,000-50,000 K Size: very large and massive Spectra: ionized helium, ultraviolet continuum Examples: 10 Lacertra, Zeta Puppis, and Iota Orionis A The rock stars of the universe-they live fast, die young and leave a spectacularlooking corpse!
17 Color: blue Temperature: 10,000-28,000 K Size: large and massive Spectra: neutral helium lines,some hydrogen Examples: Beta Centauri, Rigal, Spica B stars are relatively rare, comprising only 0.1% of main sequence stars.
18 Color: white Temperature: 75,000-10,000 K Size: moderate sized, very luminous Spectra: strong hydrogen lines, ionized metals Examples: Alpha Canis Majoris (Sirius) and Alpha Lyrae (Vega) A stars are amongst the most common naked eye stars.
19 Color: white-yellow Temperature: 6,000-75,000 K Size: 1.2 to 1.6 times bigger than the Sun Spectra: weak hydrogen lines, strong Calcium and other ionized metals Examples: Canopus, Procyon Often used as targets for extrasolar planet searches and SETI programs.
20 Color: yellow Temperature: 5,000-6,000 K Size: 0.8 to 1.1 times the mass of the Sun Spectra: weak hydrogen lines, neutral and ionized metals Examples: Alpha Centauri A, Capella The best known example of a G star is our SUN!
21 Color: orange Temperature: 3,500-5,000 K Size: smaller and cooler than the Sun Spectra: faint hydrogen lines, strong neutral metallic lines Examples: Alpha Boötis (Arcturus) and Alpha Tauri (Aldebaran) Also used as targets for extrasolar planet searches like project Ozma in 1960.
22 Color: red Temperature: 2,500-3,500 K Size: range from (main sequencesupergiants) times the mass of the Sun Spectra: strong metallic lines and wide titanium oxide bands Examples: Antares and Betelgeuse Most common class by number of stars, since 90% of all stars are red dwarfs.
23 Other Spectral Types W: Up to 70,000 K - Wolf-Rayet stars L: 1,500-2,000 K - Stars with masses insufficient to run the regular hydrogen fusion process (brown dwarfs).also contain lithium which is rapidly destroyed in hotter stars. T: 1,000 K - Cooler brown dwarfs with methane in the spectrum. C: Carbon stars. R: Formerly a class on its own representing the carbon star equivalent of Class K stars N: Formerly a class on its own representing the carbon star equivalent of Class M stars S: Similar to Class M stars, but with zirconium oxide replacing the regular titanium oxide. D: White dwarfs
LAB: Star Classification
Name: LAB: Star Classification INTRODUCTION: Like most scientists, astronomers like to categorize the Universe around them, and stars are no exception. Here s how astronomers classify stars into different
More informationProperties of Stars & H-R Diagram
Properties of Stars & H-R Diagram What is a star? A cloud of gas, mainly hydrogen and helium The core is so hot/dense that nuclear fusion can occur. The fusion converts light nuclei (elements) into heavier
More informationMy God, it s full of stars! AST 248
My God, it s full of stars! AST 248 N * The number of stars in the Galaxy N = N * f s f p n h f l f i f c L/T The Galaxy M31, the Andromeda Galaxy 2 million light years from Earth The Shape of the Galaxy
More informationChapter 15: Surveying the Stars
Chapter 15 Lecture Chapter 15: Surveying the Stars Surveying the Stars 15.1 Properties of Stars Our goals for learning: How do we measure stellar luminosities? How do we measure stellar temperatures? How
More informationChapter 15 Surveying the Stars
Chapter 15 Surveying the Stars 15.1 Properties of Stars Our goals for learning How do we measure stellar luminosities? How do we measure stellar temperatures? How do we measure stellar masses? How do we
More informationThe Cosmic Perspective. Surveying the Properties of Stars. Surveying the Stars. How do we measure stellar luminosities?
Surveying the Stars Chapter 15 Lecture The Cosmic Perspective 15.1 Properties of Stars Our goals for learning: How do we measure stellar luminosities? How do we measure stellar temperatures? How do we
More informationChapter 15 Surveying the Stars Properties of Stars
Chapter 15 Surveying the Stars 15.1 Properties of Stars Our goals for learning: How do we measure stellar luminosities? How do we measure stellar temperatures? How do we measure stellar masses? Luminosity:
More informationChapter 15 Surveying the Stars Pearson Education, Inc.
Chapter 15 Surveying the Stars 15.1 Properties of Stars Our goals for learning: How do we measure stellar luminosities? How do we measure stellar temperatures? How do we measure stellar masses? 1. How
More informationStellar Spectrum Classification Lab Activity
Stellar Spectrum Classification Lab Activity Directions In this exercise you will be given a table of the standard spectral classes and a number of sample spectra to be used as the accepted spectra. While
More informationMass-Luminosity and Stellar Lifetimes WS
Name Mass-Luminosity and Stellar Lifetimes WS The graph shows the Mass-Luminosity Relationship for main sequence stars. Use it to answer questions 1-3. 1) A star with a mass of 0.5 solar masses would be
More informationBook page cgrahamphysics.com Stellar Spectra
Book page 650-652 Stellar Spectra Emission and absorption Spectra The black lines of the absorption spectrum match up with the bright lines of the emission spectrum Spectra unique to each element Emission
More informationStarTalk. Sanjay Yengul May "To know ourselves, we must know the stars."
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?
More informationThe Hertzprung-Russell (HR) Diagram
Name: Partner(s): 1102 or 3311: Desk # Date: The Hertzprung-Russell (HR) Diagram Purpose Reproduce Hertzsprung s and Russell s simultaneous discovery Investigate the relationships between luminosity, mass,
More informationSpectral Classification of Stars
Department of Physics and Geology Spectral Classification of Stars Astronomy 1402 Part 1: Background Spectral Classification of Stars 1.1 Spectral Types: O, B, A, F, G, K, M On a dark, clear night far
More informationThe Hertzsprung - Russell Diagram Laboratory 11
The Hertzsprung - Russell Diagram Laboratory 11 Objective: In this laboratory a random sample of stars will be used to create a HR Diagram. From the diagram it will be determined which category certain
More informationHOMEWORK - Chapter 17 The Stars
Astronomy 20 HOMEWORK - Chapter 7 The Stars Use a calculator whenever necessary. For full credit, always show your work and explain how you got your answer in full, complete sentences on a separate sheet
More informationDaily Science 04/04/2017
Daily Science 04/04/2017 Which statement best describes the difference between type A stars and type B stars as shown in the diagram? a. Type A stars burn for a shorter amount of time than type B stars.
More informationChapter 10 Measuring the Stars
Chapter 10 Measuring the Stars Some of the topics included in this chapter Stellar parallax Distance to the stars Stellar motion Luminosity and apparent brightness of stars The magnitude scale Stellar
More informationReview Chapter 10. 2) A parsec is slightly more than 200,000 AU. 2)
Review Chapter 10 TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 1) A parsec is about 3.3 light-years. 1) 2) A parsec is slightly more than 200,000 AU. 2) 3) The nearest
More informationParallax: Measuring the distance to Stars
Measuring the Stars Parallax: Measuring the distance to Stars Use Earth s orbit as baseline Parallactic angle = 1/2 angular shift Distance from the Sun required for a star to have a parallactic angle of
More informationEVOLUTION OF STARS HERTZSPRUNG-RUSSELL DIAGRAM
VISUAL PHYSICS ONLINE EVOLUTION OF STARS HERTZSPRUNG-RUSSELL DIAGRAM The total power radiated by a star is called its intrinsic luminosity L (luminosity). The apparent brightness (apparent luminosity)
More informationH-R Diagram Lab. Vocabulary:
H-R Diagram Lab Vocabulary: luminosity: brightness dependent on a star s size; temperature and distance spectral class: classification of stars by their spectrum and luminosity magnitude: measure of the
More informationStars: some basic characteristics
Stars: some basic characteristics Stars! How bright are they? How massive are they? What are the different types? How long do they live? How hot are they? Stellar brightness and luminosity The apparent
More informationExploratorium Teacher Institute page 1 Linda S. Shore
Exploratorium Teacher Institute page 1 Growing Up A Star This activity helps students understand and interpret the Hertzsprung Russell (HR) diagram a graphical representation of how stars evolve that is
More informationStars. For Jupiter: M/Msun = 0.001
Stars Stars are classified by spectral classes O,B,A,F,G,K,M Oh be a fine girl (or guy), kiss me! Key here is the effective temperature of the star (surface temperature) Difference in spectrum is due to
More informationThe Sun and the Stars
Classification of stellar spectra Potted History : 1802 William Wallaston showed that the spectrum of the sun is not simply a continuous spectrum, but is broken up by a series of dark lines (absorption
More informationCalculating Main Sequence Lifetimes
Calculating Main Sequence ifetimes At the beginning of the twentieth century two astronomers, the Danish E. Hertzsprung and the American H. N. Russell, established a correlation between two important stellar
More informationLecture 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
More informationStars III The Hertzsprung-Russell Diagram
Stars III The Hertzsprung-Russell Diagram Attendance Quiz Are you here today? (a) yes Here! (b) no (c) here is such a 90 s concept Today s Topics (first half) Spectral sequence and spectral types Spectral
More informationOTHER MOTIONS. Just so far away they appear to move very slowly
OTHER MOTIONS The position of a nearby star changing over a year gives us parallax Stars can also move on their own Real motion, not just our point of view They are just balls of gas and are moving around
More informationa. Star A c. The two stars are the same distance b. Star B d. Not enough information
Name: Astro 102 S17 Test 1 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Your test is Version A. Please fill in the circle for A for this question on
More informationChapter 15 Lecture. The Cosmic Perspective Seventh Edition. Surveying the Stars Pearson Education, Inc.
Chapter 15 Lecture The Cosmic Perspective Seventh Edition Surveying the Stars 15.1 Properties of Stars Our goals for learning: How do we measure stellar luminosities? How do we measure stellar temperatures?
More informationTypes 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
More informationMagnitudes. How Powerful Are the Stars? Luminosities of Different Stars
How Powerful Are the Stars? Some stars are more powerful than others Power is energy output per. (Example: 00 Watts = 00 joules per second) Astronomers measure the power, or brightness of stars in ways:
More informationY Centauri A 6. Alpha O Centauri B 7. Alpha
H-R Star Spectrum Lab The H-R diagram, as it s known for short, plots a star s luminosity its true brightness against its surface temperature in Kelvin. Are there patterns that emerge and what does this
More informationWhat do the Roman numerals mean and how do stars die
What do the Roman numerals mean and how do stars die What is luminosity? Luminosity is the energy emitted from a star, or basically how bright it is compared to our Sun The higher the luminosity, the higher
More informationOhio University - Lancaster Campus slide 1 of 47 Spring 2009 PSC 100. A star s color, temperature, size, brightness and distance are all related!
Ohio University - Lancaster Campus slide 1 of 47 A star s color, temperature, size, brightness and distance are all related! Ohio University - Lancaster Campus slide 2 of 47 The Beginnings Late 1800 s,
More informationAstronomy 210 Spring 2017: Quiz 5 Question Packet 1. can: 2. An electron moving between energy levels
Permitted energy levels Astronomy 210 Spring 2017: Quiz 5 Question Packet 1 1. An electron in energy level 1 2 can: (A) only emit a photon. (B) only absorb a photon. (C) either emit, or absorb a photon.
More informationDetermining the Properties of the Stars
Determining the Properties of the Stars This set of notes by Nick Strobel covers: The properties of stars--their distances, luminosities, compositions, velocities, masses, radii, and how we determine those
More informationLines of Hydrogen. Most prominent lines in many astronomical objects: Balmer lines of hydrogen
The Family of Stars Lines of Hydrogen Most prominent lines in many astronomical objects: Balmer lines of hydrogen The Balmer Thermometer Balmer line strength is sensitive to temperature: Most hydrogen
More informationChapter 8: The Family of Stars
Chapter 8: The Family of Stars We already know how to determine a star s surface temperature chemical composition motion Next, we will learn how we can determine its distance luminosity radius mass Measuring
More informationAstr 2320 Tues. March 7, 2017 Today s Topics
Astr 2320 Tues. March 7, 2017 Today s Topics Chapter 13: Stars: Binary Stars Determination of Stellar Properties vi Binary Stars Classification of Binary Stars Visual Binaries Both stars visible Only one
More informationHR Diagram Student Guide
Name: HR Diagram Student Guide Pretest Score: Background Information Work through the background sections on Spectral Classification, Luminosity, and the Hertzsprung-Russell Diagram. Then complete the
More informationAnnouncements. 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
More informationChapter 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
More informationAstronomy 113. Dr. Joseph E. Pesce, Ph.D. Dr. Joseph E. Pesce, Ph.D.
Astronomy 113 Dr. Joseph E. Pesce, Ph.D. The Nature of Stars 8-2 Parallax For nearby stars - measure distances with parallax July 1 AU d p A A A January ³ d = 1/p (arcsec) [pc] ³ 1pc when p=1arcsec; 1pc=206,265AU=3
More informationPosition 1 Position 2 6 after position 1 Distance between positions 1 and 2 is the Bigger = bigger parallax (Ɵ)
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
More informationBased on the reduction of the intensity of the light from a star with distance. It drops off with the inverse square of the distance.
6/28 Based on the reduction of the intensity of the light from a star with distance. It drops off with the inverse square of the distance. Intensity is power per unit area of electromagnetic radiation.
More informationASTR-1020: Astronomy II Course Lecture Notes Section III
ASTR-1020: Astronomy II Course Lecture Notes Section III Dr. Donald G. Luttermoser East Tennessee State University Edition 4.0 Abstract These class notes are designed for use of the instructor and students
More informationSun. Sirius. Tuesday, February 21, 2012
Spectral Classification of Stars Sun Sirius Stellar Classification Spectral Lines H Fe Na H Ca H Spectral Classification of Stars Timeline: 1890s Edward C. Pickering (1846-1919) and Williamina P. Fleming
More informationLecture 10: The Hertzsprung-Russell Diagram Reading: Sections
Lecture 10: The Hertzsprung-Russell Diagram Reading: Sections 19.7-19.8 Key Ideas The Hertzsprung-Russell (H-R) Diagram Plot of Luminosity vs. Temperature for stars Features: Main Sequence Giant & Supergiant
More informationChapter 11 Surveying the Stars
Chapter 11 Surveying the Stars Luminosity Luminosity: Rate of energy emitted by star every second. Apparent brightness (flux): Amount of energy passing through every second per unit area. Luninosity =
More information1. Basic Properties of Stars
1. Basic Properties of Stars This is the Sun during a total eclipse. The Sun, our closest star, is very much representative of the objects that we will study during this module, namely stars. Much of the
More informationBlack Hole Binary System. Outline - Feb. 25, Constraining the Size of the Region that Contains the Invisible Mass
Outline - Feb. 25, 2010 Black Hole Binary System Observational evidence for Black Holes (pgs. 600-601) Properties of Stars (Ch. 16) Luminosities (pgs. 519-523) Temperatures (pg. 524) Optical image of Cygnus
More informationPr P ope p rti t es s of o f St S a t rs
Properties of Stars Distances Parallax ( Triangulation ): - observe object from two separate points - use orbit of the Earth (1 AU) - measure angular shift of object - angle depends on distance to object
More informationAstron 104 Laboratory #8 The H-R Diagram
Name: Date: Section: Astron 104 Laboratory #8 The H-R Diagram Section 10.1, 10.5 Introduction The Hertzsprung-Russell diagram, or H-R diagram for short, relates two fundamental properties of stars and
More informationAgenda for Ast 309N, Sep. 27. Measuring Masses from Binary Stars
Agenda for Ast 309N, Sep. 27 Quiz 3 The role of stellar mass Ages of star clusters Exam 1, Thurs. Oct. 4 Study guide out on 9/28 Next topic: brown dwarfs and extrasolar planets 1 This image of the central
More informationAstronomy-part 3 notes Properties of Stars
Astronomy-part 3 notes Properties of Stars What are Stars? Hot balls of that shine because nuclear fusion (hydrogen to helium) is happening at their cores. They create their own. Have different which allow
More informationλ = 650 nm = c = m s 1 f =? c = fλ f = c λ = ( m s 1 ) ( m) = = Hz T = 1 f 4.
Chapter 13 Stars Section 13.1 Astronomical measurements Worked example: Try yourself 13.1.1 CALCULATING THE FREQUENCY AND PERIOD OF LIGHT The speed of light in a vacuum is approximately 3.0 10 8 m s 1.
More informationStars and HR Diagrams
Stars and HR Diagrams Elements are not Elementary: the Building Blocks of Nature Atoms are made from protons, neutrons, electrons Chemical elements are named by the number A of protons in their nucleus
More informationSelected Questions from Minute Papers. Outline - March 2, Stellar Properties. Stellar Properties Recap. Stellar properties recap
Black Holes: Selected Questions from Minute Papers Will all the material in the Milky Way eventually be sucked into the BH at the center? Does the star that gives up mass to a BH eventually get pulled
More information! p. 1. Observations. 1.1 Parameters
1 Observations 11 Parameters - Distance d : measured by triangulation (parallax method), or the amount that the star has dimmed (if it s the same type of star as the Sun ) - Brightness or flux f : energy
More informationAstron 104 Laboratory #9 The H-R Diagram
Name: Date: Section: Astron 104 Laboratory #9 The H-R Diagram Section 10.1, 10.5 If we know the temperature of a star (or its Spectral Type) and the stars intrinsic brightness (or luminosity), a great
More informationAnnouncements. Office hours this Tuesday will be 1-2 pm.
Announcements Scores for first exam on ICON The average was 53.4 or 67%. The curve is A:80-68, B:64-56, C:52-40, D:36-32, F < 30. Material for problem about Kepler satellite was not adequately covered,
More informationStar Formation A cloud of gas and dust, called a nebula, begins spinning & heating up. Eventually, it gets hot enough for fusion to take place, and a
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
More informationMeasuring Radial & Tangential Velocity. Radial velocity measurement. Tangential velocity measurement. Measure the star s Doppler shift
17. The Nature of the Stars Parallax reveals stellar distance Stellar distance reveals luminosity Luminosity reveals total energy production The stellar magnitude scale Surface temperature determines stellar
More informationTemperature, Blackbodies & Basic Spectral Characteristics.
Temperature, Blackbodies & Basic Spectral Characteristics. Things that have one primary temperature but also exhibit a range of temperatures are known in physics as blackbodies. They radiate energy thermally.
More informationThe Family of Stars. Chapter 13. Triangulation. Trigonometric Parallax. Calculating Distance Using Parallax. Calculating Distance Using Parallax
The Family of Stars Chapter 13 Measuring the Properties of Stars 1 Those tiny glints of light in the night sky are in reality huge, dazzling balls of gas, many of which are vastly larger and brighter than
More informationExam 1 will cover. The Day of the Exam. Astronomy Picture of the Day: Today s Class: Measuring temperatures of stars
September 25, 2013 Reading: Chapter 15, section 15.1. Exam 1 next class! Review Session tomorrow night, Sep. 26, at 7 pm in Duane G2B47. Naked eye observing session tonight at 8 pm. Volunteers for Astronomy
More informationAstronomy 110 Homework #07 Assigned: 03/06/2007 Due: 03/13/2007. Name: (Answer Key)
Astronomy 110 Homework #07 Assigned: 03/06/2007 Due: 03/13/2007 Name: (Answer Key) Directions: Listed below are twenty (20) multiple-choice questions based on the material covered by the lectures thus
More informationPhys 100 Astronomy (Dr. Ilias Fernini) Review Questions for Chapter 9
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
More informationTHE STARS. Information and contacts: -
THE STARS G. Iafrate (a), M. Ramella (a) and V. Bologna (b) (a) INAF - Astronomical Observatory of Trieste (b) Istituto Comprensivo S. Giovanni Sc. Sec. di primo grado M. Codermatz" - Trieste Information
More informationASTR 1120 February 6
ASTR 1120 February 6. First Exam: Thursday, February 20 Recitations will be held Duane G131, Mondays 5-5:50 Website http://casa.colorado.edu/~wcash/aps1120/aps1120.html Third Homework Posted to Web Due
More informationMeasuring Radial & Tangential Velocity. Radial velocity measurement. Tangential velocity measurement. Measure the star s Doppler shift
17. The Nature of the Stars Parallax reveals stellar distance Stellar distance reveals luminosity Luminosity reveals total energy production The stellar magnitude scale Surface temperature determines stellar
More informationLecture 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
More information18. Which graph best represents the relationship between the number of sunspots and the amount of magnetic activity in the Sun?
1. Which star has a surface temperature most similar to the surface temperature of Alpha Centauri? A) Polaris B) Betelgeuse C) Procyon B D) Sirius 2. Giant stars have greater luminosity than our sun mainly
More informationHomework 2 AST 301, Sections and 46850, Spring NAME Student EID Score: on last page. Due Tuesday, March 1, 2016
Homework 2 AST 301, Sections 46845 and 46850, Spring 2016 NAME Student EID Score: on last page Due Tuesday, March 1, 2016 Questions A C should help you to understand the properties of light. Show your
More informationReview Questions for the new topics that will be on the Final Exam
Review Questions for the new topics that will be on the Final Exam Be sure to review the lecture-tutorials and the material we covered on the first three exams. How does speed differ from velocity? Give
More informationHow can we use an H-R diagram to know where a star is in its life cycle?
How can we use an H-R diagram to know where a star is in its life cycle? Just like humans, stars go through a life cycle. Over the course of their lives, stars change in ways that make each stage different
More informationThe Hertzsprung-Russell Diagram
The Hertzsprung-Russell Diagram Name: Date: 1 Introduction As you may have learned in class, the Hertzsprung-Russell Diagram, or the HR diagram, is one of the most important tools used by astronomers:
More informationReading and Announcements. Read Chapters 8.3, 11.5, 12.1 Quiz #5, Thursday, March 21 Homework #5 due Tuesday, March 19
Reading and Announcements Read Chapters 8.3, 11.5, 12.1 Quiz #5, Thursday, March 21 Homework #5 due Tuesday, March 19 Measurements of Star Properties Apparent brightness Direct measurement Parallax Distance
More informationGALAXIES AND STARS. 2. Which star has a higher luminosity and a lower temperature than the Sun? A Rigel B Barnard s Star C Alpha Centauri D Aldebaran
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
More informationFamily of stars. Fred Sarazin Physics Department, Colorado School of Mines. PHGN324: Family of stars
Family of stars Reminder: the stellar magnitude scale In the 1900 s, the magnitude scale was defined as follows: a difference of 5 in magnitude corresponds to a change of a factor 100 in brightness. Dm
More informationChapter 15 Surveying the Stars. Properties of Stars. Parallax and Distance. Distances Luminosities Temperatures Radii Masses
hapter 15 Surveying the Stars Properties of Stars istances Luminosities s Radii Masses istance Use radar in Solar System, but stars are so far we use parallax: apparent shift of a nearby object against
More informationASTRONOMY 1 EXAM 3 a Name
ASTRONOMY 1 EXAM 3 a Name Identify Terms - Matching (20 @ 1 point each = 20 pts.) Multiple Choice (25 @ 2 points each = 50 pts.) Essays (choose 3 of 4 @ 10 points each = 30 pt 1.Luminosity D 8.White dwarf
More informationA1101, Lab 5: The Hertzsprung- Russell Diagram Laboratory Worksheet
Student Name: Lab TA Name: A1101, Lab 5: The Hertzsprung- Russell Diagram Laboratory Worksheet One of the most basic physical properties of a star is its luminosity, the rate at which it radiates energy
More informationthe nature of the universe, galaxies, and stars can be determined by observations over time by using telescopes
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?
More informationGuiding Questions. Measuring Stars
Measuring Stars Guiding Questions 1. How far away are the stars? 2. What is meant by a first-magnitude or second magnitude star? 3. Why are some stars red and others blue? 4. What are the stars made of?
More informationPhotosphere. Bob Stein s simulation movie. Chromosphere. Corona. Solar wind
Photosphere Layer from which light escapes directly into space. Photosphere is what we see. Light from lower layers scatters. Q: Suppose we observe the neutrinos from the sun. The size of the sun when
More informationHertzprung-Russel and colormagnitude. ASTR320 Wednesday January 31, 2018
Hertzprung-Russel and colormagnitude diagrams ASTR320 Wednesday January 31, 2018 H-R diagram vs. Color- Magnitude Diagram (CMD) H-R diagram: Plot of Luminosity vs. Temperature CMD: Plot of magnitude vs.
More informationProperties of Stars (continued) Some Properties of Stars. What is brightness?
Properties of Stars (continued) Some Properties of Stars Luminosity Temperature of the star s surface Mass Physical size 2 Chemical makeup 3 What is brightness? Apparent brightness is the energy flux (watts/m
More informationLab 8: Stellar Classification and the H-R Diagram
Name: Section: Date: Lab 8: Stellar Classification and the H-R Diagram 1 Introduction Stellar Classification As early as the beginning of the 19th century, scientists have studied absorption spectra in
More informationAstronomy 210. Outline. Stellar Properties. The Mosquito Dilemma. Solar Observing & HW9 due April 15 th Stardial 2 is available.
Astronomy 210 Outline This Class (Lecture 31): Stars: Spectra and the H-R Diagram Next Class: Life and Death of the Sun Solar Observing & HW9 due April 15 th Stardial 2 is available. The Mosquito dilemma
More informationVocabulary. Section Resources
Section 26.2 26.2 Stars 1 FOCUS Objectives 26.2.1 Demonstrate how distance to a star is measured. 26.2.2 Classify stars according to chemical and physical properties. 26.2.3 Interpret the H-R diagram.
More informationQuestion: How do we use a Hertzsprung-Russell Diagram to explain star characteristics?
The Hertzsprung-Russell Diagram Assignment Introduction: The development of the H-R Diagram began with Danish astronomer Ejnar Hertzsprung who began plotting the stars around 1911. American astronomer
More informationTest Ques4ons. Median Grade: 82/100 High Score: 99/100
Day 11: Stars Review of Test Ar4cle Sharing Reading/Mastering Astronomy Ques4ons Lecture on Spectral Type Break Lecture on Hertzsprung- Russell Diagram L- T: H- R Diagram, p 117 Summary Test Ques4ons Median
More informationThe Hertzprung-Russell Diagram. The Hertzprung-Russell Diagram. Question
Key Concepts: Lecture 21: Measuring the properties of stars (cont.) The Hertzsprung-Russell (HR) Diagram (L versus T) The Hertzprung-Russell Diagram The Stefan-Boltzmann Law: flux emitted by a black body
More informationAssignments for Monday Oct. 22. Read Ch Do Online Exercise 10 ("H-R Diagram" tutorial)
Assignments for Monday Oct. 22 Read Ch. 13 + Do Online Exercise 10 ("H-R Diagram" tutorial) Luminosity passing through each sphere is the same. Area of sphere: 4π(radius) 2 Divide luminosity by area to
More information15.1 Properties of Stars
Surveying the Stars 15.1 Properties of Stars Our goals for learning: How do we measure stellar luminosities? How do we measure stellar temperatures? How do we measure stellar masses? How do we measure
More informationStars: Intro & Classification
Stars: Intro & Classification Astronomy 1 Elementary Astronomy LA Mission College Spring F2015 Quotes & Cartoon of the Day The wonder is, not that the field of stars of so vast, but that man has measured
More information