Sun. Sirius. Tuesday, February 21, 2012
|
|
- Carmel Palmer
- 5 years ago
- Views:
Transcription
1 Spectral Classification of Stars Sun Sirius
2 Stellar Classification Spectral Lines H Fe Na H Ca H
3 Spectral Classification of Stars Timeline: 1890s Edward C. Pickering ( ) and Williamina P. Fleming ( ) label spectra alphabetically according to strength of Hydrogen (Balmer) lines, beginning with A (strongest). 1890s Antonia Maury ( ) developed a classification scheme based on the width of spectral lines. Would place B stars before A stars Annie Cannon ( ), brilliantly combined the above. Rearranged sequence, O before B before A, added decimal divisions (A0...A9) and consolidated classes. Led to classification scheme still used by astronomers today! OBAFGKM (Oh Be A Fine Guy/Girl, Kiss Me) Early Type Stars Late Type Stars
4 Timeline: Spectral Classification of Stars 1901 Annie Cannon ( ), brilliantly combined the above. Rearranged sequence, O before B before A, added decimal divisions (A0...A9) and consolidated classes. Led to classification scheme still used by astronomers today! OBAFGKM (Oh Be A Fine Guy/Girl, Kiss Me) Early Type Stars : Stars near the beginning of Sequence Late Type Stars : Stars near the end of the Sequence. One can mix the definitions: K0 star is an early-type K star. B9 is a late-type B star During 1990s Annie Cannon classified 200,000 spectra, listed in the Henry Draper Catalog. Catalog ID s are HD (ID for Betelgeuse in the constellation Orion). Two new letters added to Sequence for very cool, Brown-Dwarf stars. L spectral types (T= K) and T types (T < 1300 K). OBAFGKMLT (Oh Be A Fine Guy/Girl, Kiss Me - Less Talk!)
5 Spectral Classification of Stars Hotter Cooler Spectral Type O B A F G K M L T Characteristics Hottest blue-white stars, few lines. Strong He II (He + ) absorption lines. He I (neutral helium) stronger). Hot blue-white. He I (neutral Helium), strongest at B2. H I (neutral Hydrogen) stronger. White stars. Balmer absorption lines strongest at A0 (Vega), weaker in later-type A stars. Strong Ca II (Ca + ) lines. Yellow-white stars. Ca II lines strengthen to later types. F-stars. Balmer lines strengthen to earlier type F-stars. Yellow stars (Sun is a G5 star). Ca II lines become stronger. Fe I (neutral iron) lines become strong. Cool orange stars. Ca II (H and K) lines strongest at K0, becoming weaker in later stars. Spectra dominated by metal absorption lines. Cool red stars. Spectra dominated by molecular absorption bands, e.g., TiO (titanium oxide). Neutral metal lines strong. Very cool, dark red (brown dwarfs). Brighter in Infrared than visible. Strong molecular absorption bands, e.g., CrH, FeH, water, CO. TiO weakening. Coolest stars. Strong methane (CH4), weakening CO bands.
6 Spectral Classification of Stars
7 Spectral Classification of Stars
8 Spectral Classification of Stars
9 Spectral Classification of Stars
10 Spectral Classification of Stars
11 Stellar Classification Spectral Lines H Fe Na H Ca H
12 Spectral Classification of Stars Physical Description Hydrogen when T < 9900 K Majority of electrons in ground state, n=1 Hydrogen when T = 9900 K Majority of electrons in first excited, n=2 state, and capable of producing Balmer lines Hydrogen when T > 9900 K Majority of electrons unbound, ionized hydrogen.
13 Spectral Classification of Stars Physical Description Stars are not composed of pure hydrogen, but nearly all atoms (mostly H, He, and metals = anything not H or He). Typically 1 He atom for every 10 H atoms (and even fewer metals). Helium (and metals) provide more electrons, which can recombine with ionized H. So, it takes higher temperatures to achieve same degree of H ionization when He and metals are present. Abundance is = log10(nelement/nh) I.e., Abudance of Oxygen = 8.83, which means: 8.83 = log10(no/nh) + 12 NO/NH = = /1480 There is one Oxygen atom for every 1480 H atoms! Most Abundant Elements in the Solar Photosphere. Element Atomic # Log Relative Abundance H He ± O ± 0.06 C ± 0.06 Ne ± 0.06 N ± 0.06 Mg ± 0.05 Si ± 0.05 Fe ± 0.05 S ± 0.11 Al ± 0.07 Ar ± 0.06 Ca ± 0.02 Na ± 0.03 Ni ± 0.04
14 Spectral Classification of Stars Physical Description In 1925, Cecilia Payne ( ) calculate the relative abundances of 18 elements in stellar atmospheres (one of the most brilliant PhD theses ever in astronomy).
15 Spectral Classification of Stars Hertzsprung-Russell Diagram How would you measure a star s mass?
16 Spectral Classification of Stars Hertzsprung-Russell Diagram How would you measure a star s mass? Answer: Kepler s Laws. Works well for binary stars. m1 r1 + = r2 m2 R = m1r1 + m2r2 m1 + m2 = 0 m1 m2 r2 = = r1 a2 a1
17 Animations of binary Stars:
18 Binary Stars Term binary was first used by Sir Williams Herschel in "If, on the contrary, two stars should really be situated very near each other, and at the same time so far insulated as not to be materially affected by the attractions of neighbouring stars, they will then compose a separate system, and remain united by the bond of their own mutual gravitation towards each other. This should be called a real double star; and any two stars that are thus mutually connected, form the binary sidereal system which we are now to consider."
19 Binary Stars Two Stars in Albireo system.
20 Binary Stars Sirius A brightest star in the sky m = In 1844, Friedrich Bessel deduced it was a binary. In 1862 Alvan Graham Clark discovered the companion. Sirius B m = 8.30
21 Spectral Classification of Stars Hertzsprung-Russell Diagram How would you measure a star s mass? angle of inclination For circular orbits, v1 = 2πa1/P m1 = v2 Plane of Sky Orbital Plane m2 m2 Determine radial component of velocities, vr, using doppler-shifted spectral lines. v1r=v1 sin(i) & v2r=v2 sin(i) v1 To Earth m1 m2 = v2r / sin(i) v1r / sin(i) = v2r v1r Therefore, we can determine the mass ratio without knowing the angle of inclination! m1
22 Spectral Classification of Stars Hertzsprung-Russell Diagram How would you measure a star s mass? Need one other equation to relate m1 and m2. Comes from Kepler s 3rd law, replace a = a1 + a2 a = a1 + a2 = (P/2π) v1 + (P/2π)v2 = (P/2π) (v1+v2) Kepler s 3rd law, (P 2 = 4π 2 a 3 / GM ), becomes m1 + m2 = (P/2πG) (v1+v2) 3 Substituting v1 = v1r /sin(i), the angle of inclination. m1 + m2 = (P/2πG) (v 1r+v2r) 3 sin 3 (i)
23 Spectral Classification of Stars Hertzsprung-Russell Diagram How would you measure a star s mass? Combine our two formula: m1 m2 = v2r / sin(i) v1r / sin(i) = v2r v1r m1 + m2 = (P/2πG) (v 1r+v2r) 3 sin 3 (i) To get (rearranging terms): m2 3 (m1 + m2) 2 sin 3 (i) P = 2πG v1r 3 This is the mass function, depends only on the period, P, and radial velocity, v1r. In practice, only a spectrum for one star in binary pair is available. Mass function sets a lower limit on m2. In rare cases of eclipsing spectroscopic binaries, i 90 o and both masses can be measured directly.
24 Eclipsing Binaries: java/eclipse/eclipse.htm
25 Spectral Classification of Stars Mass-Luminosity relation
26 Spectral Classification of Stars Hertzsprung-Russell Diagram This is the Hertzprung- Russell (HR) diagram, which is a stellar classification system developed by Ejnar Hertzprung and Henry Norris Russel in Denmark around Ejnar Hertzsprung Henry Norris Russell The HR diagram relates the magnitudes and colors of stars as a function of their temperature and luminosity.
27 Henry Norris Russell s first diagram
28 Spectral Classification of Stars Enormous Range in Stellar Radii! If stars cool over time as they contract, there should be a relation between their temperatures and luminosities. R = 1 T 2 L 4πσ Hertzsprung ( ) found that stars of Late type (G and later) have a large range in luminosity. If two stars of the same spectral type (same Temperature) then more luminous star is larger. Giants: Stars with big radii & Dwarfs: Stars with small radii. Our Sun is a G0 dwarf. Similar Conclusions reached by Henry Russell ( )
29 Spectral Classification of Stars Hertzsprung-Russell Diagram
30 Spectral Classification of Stars Hertzsprung-Russell Diagram
31 Brighter 30,000 K 10,000 K 7500 K 6000 K 5000 K 4000 K 3000 K Luminosity Text HR diagram where data points show measurements from 22,000 real stars from the Hipparcos satellite. (Lines are Theoretical, expected luminosities and temperatures of stars) Temperature: Hotter Color Index: B-V
32 Brighter HR diagram Absolute Magnitude (M) (Luminosity) Spectral Type Hotter Temperature (Color, B-V)
Spectral Classification of Stars
Sun Sirius Stellar Classification Spectral Lines CaH H Fe Na H Timeline: Edward C. Pickering (1846-1919) and Williamina P. Fleming 1890s (1857-1911) label spectra alphabetically according to strength of
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 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 informationFrom measuring and classifying the stars to understanding their physics
From measuring and classifying the stars to understanding their physics What we can measure directly: Surface temperature and color Spectrum Apparent magnitude or intensity Diameter of a few nearby stars
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 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 informationLecture 14: Studying the stars. Astronomy 111 Monday October 16, 2017
Lecture 14: Studying the stars Astronomy 111 Monday October 16, 2017 Reminders Homework #7 due Monday I will give a lecture on DES and LIGO tomorrow at 4pm in the Mitchell Institute Studying the stars
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 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 informationA Stellar Spectra 3. Stars shine at night (during the day too!). A star is a self-luminous sphere of gas. Stars are held together by gravity.
Stellar Spectra Relativity and Astrophysics Lecture 12 Terry Herter Outline What is a star? Stellar Spectra Kirchhoff s Laws Spectral Classification Spectral Types: O B A F G K M L T Stellar Photometry
More informationV. Stars.
V. Stars http://sgoodwin.staff.shef.ac.uk/phy111.html 0. The local HR diagram We saw that locally we can make an HR diagram of absolute luminosity against temperature. We find a main sequence, giants and
More informationStars - spectral types
Stars - spectral types 1901: Led by Annie Jump Cannon, Harvard astronomers looked at the spectra of >200,000 stars. Classified them as A, B, C etc. Cannon rearranged them into OBAFGKM based on how lines
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 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 informationThe Spectra of Stars and Binary Stars (Masses and Radii)
The Spectra of Stars and Binary Stars (Masses and Radii) Colors of Stars Stars are made of hot, dense gas Con$nuous spectrum from the lowest visible layers ( photosphere ). Approximates a blackbody spectrum.
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 informationStellar Astrophysics: The Classification of Stellar Spectra
Stellar Astrophysics: The Classification of Stellar Spectra Temperature and Color The intensity of light emitted by three hypothetical stars is plotted against wavelength The range of visible wavelengths
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 information301 Physics 1/20/09. The Family of Stars. Chapter 12. Triangulation. Trigonometric Parallax. Course/Syllabus Overview Review of 301 stuff Start Ch.
1/20/09 Course/Syllabus Overview Review of 301 stuff Start Ch. 12 More than just knowing various facts Understand how we arrive at these conclusions 301 Physics Physics Concepts Light Properties of (frequency,wavelength,energy)
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 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 informationFYI: Spectral Classification & Stellar Spectra. 1. Read FYI: Spectral Classification A Look Back and FYI: Stellar Spectra What s in a Star?
FYI: Spectral Classification & Stellar Spectra E3:R1 1. Read FYI: Spectral Classification A Look Back and FYI: Stellar Spectra What s in a Star? As you read use the spaces below to write down any information
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 informationStellar Spectra ASTR 2110 Sarazin. Solar Spectrum
Stellar Spectra ASTR 2110 Sarazin Solar Spectrum Test #1 Monday, October 9, 11-11:50 am Ruffner G006 (classroom) You may not consult the text, your notes, or any other materials or any person Bring pencils,
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 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 informationOrganizing the Family of Stars:
Organizing the Family of Stars: We know: Stars have different temperatures, different luminosities, and different sizes. To bring some order into that zoo of different types of stars: organize them in
More informationReview of Star Intro. PHYSICS 162 Lecture 7a 1
Review of Star Intro Parallax - geometric method of determining star distance Absolute and apparent luminosity. Temperature Spectrum: What characterizes the star s surface Is related to its temperature
More informationCharacterizing Stars
Characterizing Stars 1 Guiding Questions 1. How far away are the stars? 2. What evidence do astronomers have that the Sun is a typical star? 3. What is meant by a first-magnitude or second magnitude star?
More informationDistances to the stars Friedrich Bessel Cygni 10 light years. Just beat Struve and Henderson who measured Vega and α Centauri respectively.
Distances to the stars Friedrich Bessel 1838 61 Cygni 10 light years. Just beat Struve and Henderson who measured Vega and α Centauri respectively. Distances to the stars the technique p < 1arcsecond d
More informationCharacterizing Stars. Guiding Questions. Parallax. Careful measurements of the parallaxes of stars reveal their distances
Guiding Questions Characterizing Stars 1. How far away are the stars? 2. What evidence do astronomers have that the Sun is a typical star? 3. What is meant by a first-magnitude or second magnitude star?
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 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 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 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 information13.3 Spectra of Stars
13.3 Spectra of Stars A star's spectrum depicts the energy it emits at each wavelength and is perhaps the single most important thing we can know about the star. From the spectrum we can find the star's
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 informationStars: Stars and their Properties
Stars: Stars and their Properties Astronomy 110 Class 10 WHEN I heard the learn d astronomer; When the proofs, the figures, were ranged in columns before me; When I was shown the charts and the diagrams,
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 informationChapter 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
More informationThe Classification of Stellar Spectra Chapter 8
The Classification of Stellar Spectra Chapter 8 Star Clusters in the Large Magellanic Cloud http://www.seds.org/hst/ NGC850.html The Classification of Stellar Spectra Classification scheme developed before
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 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 informationAstronomy. 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
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 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 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 informationThe Hertzsprung-Russell Diagram
The Hertzsprung-Russell Diagram Our Objectives To determine the physical properties of the stars; to learn how they differ; and to understand why those differences arise We can now get around the problem
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 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 informationEach star is born with a specific mass. This mass is the main factor in determining the star s brightness, temperature, expected lifetime, type of
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
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 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 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 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 informationAstr 5465 Feb. 6, 2018 Today s Topics
Astr 5465 Feb. 6, 2018 Today s Topics Stars: Binary Stars Determination of Stellar Properties via Binary Stars Classification of Binary Stars Visual Binaries Both stars visible Only one star visible Spectroscopic
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 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 informationAtomic Spectra in Astrophysics
Atomic Spectra in Astrophysics Potsdam University : Dr. Lidia Oskinova lida@astro.physik.uni-potsdam.de Fundamentals of stellar classification 01 Stars are made of hot, dense gas Continuous spectrum from
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 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 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 informationAGA5802 Spectroscopy II Prism Gratings Applications
AGA5802 Spectroscopy II Prism Gratings Applications Bibliography: To Measure the Sky, Kitchin, Lena and others... Prof. Jorge Meléndez 1 Slit Basic components of the Spectrograph Prism or grating Roy &
More informationASTR Look over Chapter 15. Good things to Know. Triangulation
ASTR 1020 Look over Chapter 15 Good things to Know Triangulation Parallax Parsecs Absolute Visual Magnitude Distance Modulus Luminosity Balmer Lines Spectral Classes Hertzsprung-Russell (HR) diagram Main
More informationLAB: 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 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 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 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 informationDiscussion. Summary Clicker -- Solar Wind. What are effects of solar activity on our technological society? A. Auroral
ASTR 1040 Accel Astro: Stars & Galaxies Prof. Juri Toomre TA: Nicholas Nelson Lecture 10 Thur 10 Feb 11 zeus.colorado.edu/astr1040-toomre toomre Planetary Nebula NGC 3132 Today What can we measure in other
More information5. A particular star has an angle of parallax of 0.2 arcsecond. What is the distance to this star? A) 50 pc B) 2 pc C) 5 pc D) 0.
Name: Date: 1. How far away is the nearest star beyond the Sun, in parsecs? A) between 1 and 2 pc B) about 12 pc C) about 4 pc D) between 1/2 and 1 pc 2. Parallax of a nearby star is used to estimate its
More informationParallax: Space Observatories. Stars, Galaxies & the Universe Announcements. Stars, Galaxies & Universe Lecture #7 Outline
Stars, Galaxies & the Universe Announcements HW#4: posted Thursday; due Monday (9/20) Reading Quiz on Ch. 16.5 Monday (9/20) Exam #1 (Next Wednesday 9/22) In class (50 minutes) first 20 minutes: review
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 informationUnit 2 Lesson 2 Stars. Copyright Houghton Mifflin Harcourt Publishing Company
Florida Benchmarks SC.8.N.1.6 Understand that scientific investigations involve the collection of relevant empirical evidence, the use of logical reasoning, and the application of imagination in devising
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 informationStellar Spectra ASTR 2120 Sarazin. Solar Spectrum
Stellar Spectra ASTR 2120 Sarazin Solar Spectrum Solar Prominence Sep. 14, 1999 Solar Activity Due to rotation, convection, and magnetic field (Section 7.2 review) Charged Particles in Magnetic Fields
More informationStars. Properties of Stars
Stars Properties of Stars Do all stars appear the same? How are they different? Which one looks the coolest? Hottest? Are they all the same brightness? Do they all look the same size? Luminosity: Amount
More informationHertzsprung-Russell Diagram, Flux, Luminosity, Magnitude 10 Oct
Russell Diagram, Flux, Luminosity, Magnitude 10 Oct Outline Review of 7 Oct Thermal radiation Wien s Law Stefan Boltzmann Law How to measure temperature of stars. AJ Cannon s method of classifying spectra.
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 informationTypes of Stars 1/31/14 O B A F G K M. 8-6 Luminosity. 8-7 Stellar Temperatures
Astronomy 113 Dr. Joseph E. Pesce, Ph.D. The Nature of Stars For nearby stars - measure distances with parallax 1 AU d p 8-2 Parallax A January ³ d = 1/p (arcsec) [pc] ³ 1pc when p=1arcsec; 1pc=206,265AU=3
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 informationThe H-R Diagram. Image credit: NOAO
The H-R Diagram Image credit: NOAO Luminosity, Temperature, Radius Recall: apparent magnitude, absolute magnitude, and distance are related. We now have a method for finding the luminosity and a method
More informationCHAPTER 29: STARS BELL RINGER:
CHAPTER 29: STARS BELL RINGER: Where does the energy of the Sun come from? Compare the size of the Sun to the size of Earth. 1 CHAPTER 29.1: THE SUN What are the properties of the Sun? What are the layers
More informationObserved Properties of Stars - 2 ASTR 2110 Sarazin
Observed Properties of Stars - 2 ASTR 2110 Sarazin Properties Location Distance Speed Radial velocity Proper motion Luminosity, Flux Magnitudes Magnitudes Stellar Colors Stellar Colors Stellar Colors Stars
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 informationMeasuring the Properties of Stars (ch. 17) [Material in smaller font on this page will not be present on the exam]
Measuring the Properties of Stars (ch. 17) [Material in smaller font on this page will not be present on the exam] Although we can be certain that other stars are as complex as the Sun, we will try to
More informationChapter 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
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 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 informationHertzsprung-Russell Diagram 7 Oct
Hertzsprung-Russell Diagram 7 Oct Outline Thermal radiation Wien s Law Stefan Boltzmann Law Hertzsprung Russell diagram There are 3 types of stars: main sequence or dwarfs, giants, white dwarfs Missouri
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 informationThe Life Histories of Stars I. Birth and Violent Lives
The Life Histories of Stars I Birth and Violent Lives Stellar evolution--first problem for new discipline of astrophysics What is a star? What is it made of? How does it produce and release energy? How
More informationChapter 6. Atoms and Starlight
Chapter 6 Atoms and Starlight What is light? Light is an electromagnetic wave. Wavelength and Frequency wavelength frequency = speed of light = constant Particles of Light Particles of light are called
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 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 informationThey developed a graph, called the H-R diagram, that relates the temperature of a star to its absolute magnitude.
Ejnar Hertzsprung and Henry Russell noticed that stars with higher temperatures and large sizes also have brighter absolute magnitudes the actual amount of light given off by a star. (also referred to
More informationMeasuring the Stars. The measurement of distances The family of distance-measurement techniques used by astronomers to chart the universe is called
Measuring the Stars How to measure: Distance Stellar motion Luminosity Temperature Size Evolutionary stage (H-R diagram) Cosmic distances Mass The measurement of distances The family of distance-measurement
More informationObserved Properties of Stars - 2 ASTR 2120 Sarazin
Observed Properties of Stars - 2 ASTR 2120 Sarazin Properties Location Distance Speed Radial velocity Proper motion Luminosity, Flux Magnitudes Magnitudes Hipparchus 1) Classified stars by brightness,
More informationThe Hertzsprung Russell Diagram. The Main Sequence
The Hertzsprung Russell Diagram H R diagram plots stellar luminosity against surface temperature Luminosity ranges 10-4 10 4 L. Temperature ranges by a factor of 10 increases to the left spectral sequence
More informationDeducing Temperatures and Luminosities of Stars (and other objects ) Electromagnetic Fields. Sinusoidal Fields
Deducing Temperatures and Luminosities of Stars (and other objects ) Review: Electromagnetic Radiation Gamma Rays X Rays Ultraviolet (UV) Visible Light Infrared (IR) Increasing energy Microwaves Radio
More information6. Stellar spectra. excitation and ionization, Saha s equation stellar spectral classification Balmer jump, H -
6. Stellar spectra excitation and ionization, Saha s equation stellar spectral classification Balmer jump, H - 1 Occupation numbers: LTE case Absorption coefficient: κ ν = n i σ ν$ à calculation of occupation
More information