Taking fingerprints of stars, galaxies, and interstellar gas clouds

Size: px
Start display at page:

Download "Taking fingerprints of stars, galaxies, and interstellar gas clouds"

Transcription

1 - - Taking fingerprints of stars, galaxies, and interstellar gas clouds Absorption and emission from atoms, ions, and molecules Periodic Table of Elements The universe is mostly hydrogen H and helium He (97%) These (and a little lithium, Li) were only elements created in Big Bang ALL heavier elements have been (and are still being) manufactured in stars, via nuclear fusion Each element has own characteristic set of energies at which it absorbs or radiates electromagnetic radiation Planck s s Theory, 1901 Light with wavelength has frequency ν = c/ can exchange energy with matter (atoms) in units of: E = hν h is Planck s constant h = Joule-seconds The Bohr Atom Model of Hydrogen atom Introduced by Niels Bohr early in 1913 to explain emission and absorption of light by H 1 proton ( nucleus ) orbited by 1 electron + The Bohr Atom Electron orbits have fixed sizes orbitals Not Like Planets in a Solar System atomic orbitals are QUANTIZED only some orbital radii are allowed was very confusing to physicists first deduced by physicist Neils Bohr Movement of electron e - between orbitals requires absorption or radiation of energy jump from lower to higher orbital atom absorbs energy jump from higher to lower orbital atom emits energy Bohr Atom Absorption of Photon kicks electron to higher orbital + 1

2 Bohr Atom Emission of Photon makes Electron drop to lower orbital Absorption vs. Emission Atom absorbs photon if electron kicked up to a higher energy state Atom emits photon if electron drops down to a lower state Again, only a certain set of energy states is allowed set of states depends on the atom or molecule Ensembles (Groups) of Atoms Individual H atoms in a group of H atoms have different states (are in different orbitals ) Electrons in some atoms are in low states and are more likely to absorb photons Electrons in some atoms are in high states and more likely to emit photons What determines the distribution of states of a group of atoms? Ensemble of Atoms in Low States Ready to Absorb, SIR! Ensemble of Atoms in Low States Absorption lines Photons from Star at correct are absorbed, and thus removed from the observed light Absorption Line Discovered in Solar spectrum by Fraunhofer called Fraunhofer Lines Lines because they appear as dark bands superimposed on rainbow of visible spectrum 2

3 Ensemble of Atoms in High States Ready to Emit, SIR! Ensemble of Atoms in High States Photons at correct are emitted, and thus added to any observed light Emission Line Dark Background Emission line spectrum Some Atoms are in Both States (but one usually dominates) Absorption & Emission More absorption if more atoms in low state More emission if more atoms in high state Appear as Bright Bands on Faint Background Spectrum Why the Background?? Why Would Ensemble of Atoms be in High or Low State? Some other mechanism (besides light) must be at work! But what? TEMPERATURE T Effect of Thermal Energy If T 0K (ensemble of atoms is very cold), most atoms are in low state can easily absorb light If T >> 0K (ensemble of atoms is hot), the thermal energy kicks most atoms into high state can easily emit light 3

4 Sidebar: LASER Electrons in the medium (gas, solid, or diode) of a LASER are driven to high state by external energy Emit simultaneously and with same phase External Energy: electrical optical (external light source, flash lamp) Sidebar: LASER External source maintains energy inversion more electrons in high state, even during and after emission high low Absorption Emission After Driving After Emission Geometries for producing absorption lines Sun s s Fraunhofer absorption lines 1 2 The Observer Absorption lines require cool matter (gas) between observer and hot source scenario 1: cooler atmosphere of star scenario 2: cool gas cloud between star and observer (wavelengths listed in Angstroms; 1 Å = 0.1 nm) Geometries for producing emission lines Emission line spectra 1 2 The Observer Insert various emission line spectra here Emission lines require hot matter (gas) viewed against colder background scenario 1: hot corona of a star scenario 2: cold gas cloud seen against empty (colder) space 4

5 What Wavelengths are Emitted and/or Absorbed? Depends on Size of Gaps between Energy States in the atoms Energies of H Orbitals Limiting Energy Energies of Orbitals of H Transitions between Orbitals Ionization of Hydrogen Limiting Energy If electron absorbs sufficient energy E to rise above the upper limit of energy for a bound electron, then the electron becomes ionized electron escapes the proton Relate Size of Gap to Wavelength of Light Larger gaps or jumps in energy (both absorbed and emitted) photon carries more energy Recall hc 1 E E = E = hν = 2 1 Larger E Shorter bluer light Smaller E Longer redder light Relate Size of Jump to the Absorbed or Emitted Sidebar: A Common Transition Very Small E Very Long Due to spin flip of e - in Hydrogen Atom Very Small E Very Long Radio Waves High-E State Low-E State Very Large E Very Short X rays E = hc/ Joules 0.21 m = 21 cm ν MHz RADIO Wave 5

6 Sidebar: 21-cm Radio Wave of H First observed in 1951 Simultaneously Discovered at 3 observatories!! (Harvard, Leiden, Sydney) Measures the H in interstellar matter Map of Spiral Arms in Milky Way Galaxy Bohr Atom: Extension to other elements H is simplest atom, BUT concept of electron orbitals applies to all atoms Neutral atoms have equal numbers of protons (in nucleus) and electrons (orbiting nucleus) He has 2 protons & 2 electrons; Lithium (Li), 3 each; Carbon (C), 6 each, etc.... More electrons (and protons) more complicated absorption/emission spectrum Optical Emission-Line Spectrum of Young Star Emission line images Intensity (in Angstroms Å, or units of 10 nm) Planetary nebula NGC 6543 (blue: X Rays) green oxygen red hydrogen Orion Nebula Spectra of ions Emission lines from heavy ions dominate high-energy (X-ray) spectra of stars atoms stripped of one or more electrons Ions of certain heavier elements (e.g., neon and iron with only one electron) behave much like supercharged H and He Neon Iron Wavelength (in Angstroms) Molecules Also have characteristic spectra of emission and absorption lines Each molecule has particular set of allowed energies at which it absorbs or radiates Molecules are more complicated than atoms Spectra are VERY complicated Electrons shared by one (or more) atoms in molecule absorb or emit specific energies Changes in state of vibration and/or rotation are also quantized Vibration, rotation spectra unique to each molecule 6

7 Molecular Spectra Transitions between different orbitals of molecules ( electronic states) (large E) mostly in ultraviolet (UV), optical, and infrared (IR) regions of spectrum Transitions between different Vibrational states ( middlin E) mostly in the near-infrared (NIR) Transitions between different Rotational states (small E) mostly in the radio region Rank Molecular Transitions by Energy 1. UV, Visible, IR Electronic 2. NIR Vibrational 3. Radio Rotational 4. Radio H spin ν = 1420 MHz Molecular Transitions in Planetary Nebula NGC 2346 Molecular Emission: Rotational Transition Electronic Transition (visible light) Vibrational Molecular Hydrogen Transition (IR) Rotational CO (carbon monoxide) Emission from Molecular Clouds in Milky Way Q: How to Measure Spectra? A: With a Spectrum Measurer SPECTROMETER Splits light into its constituent wavelengths and measures them Mechanisms for Splitting Light 1. Optical Filters: Block light except in desired band 2. Dispersion of Glass = Differential Refraction - Prism 3. Diffraction Grating 1. Filter Spectrometer Filters in Rotating Filter Wheel Sequence of Monochrome Images thru Different Colors (How the images in the laboratory were created) 7

8 Multispectral Imaging used for Manuscripts Recall: Optical Dispersion n ultraviolet 450 nm 550 nm 650 nm near infrared Refractive Index n measures the velocity of light in matter c n = v c = velocity in vacuum meters/second v = velocity in medium measured in same units n 1.0 Refractive index n of glass decreases with increasing wavelength Make a glass device that uses optical dispersion to separate the wavelengths a PRISM White Light In Long dispersed by smallest angle θ θ Red θ Blue Problems: Glass absorbs some light Ultraviolet light Why you can t get a suntan through glass Infrared light Images taken in different will overlap Dispersion Angle θ is complicated function of wavelength Spectrometer is difficult to calibrate 8

9 3. Grating Spectrometer Interference of Light 3. Grating Spectrometer θ θ Red Different Interfere at Different θ White Light In θ Blue θ Red θ Blue Long diverges: at largest angle θ Long dispersed by largest angle θ Can be constructed for all wavelengths 3. Grating Spectrometer Uses Diffraction Grating works by interference of light Regularly spaced transparent & opaque regions Can be made without absorbing glass Used at all wavelengths (visible, UV, IR, X-Rays, ) Dispersion angle θ is proportional to Easy to calibrate! Images at different can still overlap 9

Taking Fingerprints of Stars, Galaxies, and Other Stuff. The Bohr Atom. The Bohr Atom Model of Hydrogen atom. Bohr Atom. Bohr Atom

Taking Fingerprints of Stars, Galaxies, and Other Stuff. The Bohr Atom. The Bohr Atom Model of Hydrogen atom. Bohr Atom. Bohr Atom Periodic Table of Elements Taking Fingerprints of Stars, Galaxies, and Other Stuff Absorption and Emission from Atoms, Ions, and Molecules Universe is mostly (97%) Hydrogen and Helium (H and He) The ONLY

More information

Taking fingerprints of stars, galaxies, and interstellar gas clouds. Absorption and emission from atoms, ions, and molecules

Taking fingerprints of stars, galaxies, and interstellar gas clouds. Absorption and emission from atoms, ions, and molecules Taking fingerprints of stars, galaxies, and interstellar gas clouds Absorption and emission from atoms, ions, and molecules 1 Periodic Table of Elements The universe is mostly hydrogen H and helium He

More information

Review: Properties of a wave

Review: Properties of a wave Radiation travels as waves. Waves carry information and energy. Review: Properties of a wave wavelength (λ) crest amplitude (A) trough velocity (v) λ is a distance, so its units are m, cm, or mm, etc.

More information

Chapter 5 Light and Matter

Chapter 5 Light and Matter Chapter 5 Light and Matter Stars and galaxies are too far for us to send a spacecraft or to visit (in our lifetimes). All we can receive from them is light But there is much we can learn (composition,

More information

Astronomy The Nature of Light

Astronomy The Nature of Light Astronomy The Nature of Light A. Dayle Hancock adhancock@wm.edu Small 239 Office hours: MTWR 10-11am Measuring the speed of light Light is an electromagnetic wave The relationship between Light and temperature

More information

ASTR-1010: Astronomy I Course Notes Section IV

ASTR-1010: Astronomy I Course Notes Section IV ASTR-1010: Astronomy I Course Notes Section IV Dr. Donald G. Luttermoser Department of Physics and Astronomy East Tennessee State University Edition 2.0 Abstract These class notes are designed for use

More information

Chapter 4. Spectroscopy. Dr. Tariq Al-Abdullah

Chapter 4. Spectroscopy. Dr. Tariq Al-Abdullah Chapter 4 Spectroscopy Dr. Tariq Al-Abdullah Learning Goals: 4.1 Spectral Lines 4.2 Atoms and Radiation 4.3 Formation of the Spectral Lines 4.4 Molecules 4.5 Spectral Line Analysis 2 DR. T. AL-ABDULLAH

More information

Properties of Electromagnetic Radiation Chapter 5. What is light? What is a wave? Radiation carries information

Properties of Electromagnetic Radiation Chapter 5. What is light? What is a wave? Radiation carries information Concepts: Properties of Electromagnetic Radiation Chapter 5 Electromagnetic waves Types of spectra Temperature Blackbody radiation Dual nature of radiation Atomic structure Interaction of light and matter

More information

Prof. Jeff Kenney Class 5 June 1, 2018

Prof. Jeff Kenney Class 5 June 1, 2018 www.astro.yale.edu/astro120 Prof. Jeff Kenney Class 5 June 1, 2018 to understand how we know stuff about the universe we need to understand: 1. the spectral analysis of light 2. how light interacts with

More information

The Nature of Light I: Electromagnetic Waves Spectra Kirchoff s Laws Temperature Blackbody radiation

The Nature of Light I: Electromagnetic Waves Spectra Kirchoff s Laws Temperature Blackbody radiation The Nature of Light I: Electromagnetic Waves Spectra Kirchoff s Laws Temperature Blackbody radiation Electromagnetic Radiation (How we get most of our information about the cosmos) Examples of electromagnetic

More information

Chapter 28. Atomic Physics

Chapter 28. Atomic Physics Chapter 28 Atomic Physics Sir Joseph John Thomson J. J. Thomson 1856-1940 Discovered the electron Did extensive work with cathode ray deflections 1906 Nobel Prize for discovery of electron Early Models

More information

Possible Extra Credit Option

Possible Extra Credit Option Possible Extra Credit Option Attend an advanced seminar on Astrophysics or Astronomy held by the Physics and Astronomy department. There are seminars held every 2:00 pm, Thursday, Room 190, Physics & Astronomy

More information

Chapter 10 The Interstellar Medium

Chapter 10 The Interstellar Medium Chapter 10 The Interstellar Medium Guidepost You have begun your study of the sun and other stars, but now it is time to study the thin gas and dust that drifts through space between the stars. This chapter

More information

Light and Atoms. ASTR 1120 General Astronomy: Stars & Galaxies. ASTR 1120 General Astronomy: Stars & Galaxies !ATH REVIEW: #AST CLASS: "OMEWORK #1

Light and Atoms. ASTR 1120 General Astronomy: Stars & Galaxies. ASTR 1120 General Astronomy: Stars & Galaxies !ATH REVIEW: #AST CLASS: OMEWORK #1 ASTR 1120 General Astronomy: Stars & Galaxies!ATH REVIEW: Tonight, 5-6pm, in RAMY N1B23 "OMEWORK #1 -Due THU, Sept. 10, by 5pm, on Mastering Astronomy CLASS RECORDED STARTED - INFO WILL BE POSTED on CULEARN

More information

AST 105 Intro Astronomy The Solar System. MIDTERM II: Tuesday, April 5 [covering Lectures 10 through 16]

AST 105 Intro Astronomy The Solar System. MIDTERM II: Tuesday, April 5 [covering Lectures 10 through 16] AST 105 Intro Astronomy The Solar System MIDTERM II: Tuesday, April 5 [covering Lectures 10 through 16] REVIEW Light as Information Bearer We can separate light into its different wavelengths (spectrum).

More information

Atoms and Spectroscopy

Atoms and Spectroscopy Atoms and Spectroscopy Lecture 3 1 ONE SMALL STEP FOR MAN ONE GIANT LEAP FOR MANKIND 2 FROM ATOMS TO STARS AND GALAXIES HOW DO WE KNOW? Observations The Scientific Method Hypothesis Verifications LAW 3

More information

Recall: The Importance of Light

Recall: The Importance of Light Key Concepts: Lecture 19: Light Light: wave-like behavior Light: particle-like behavior Light: Interaction with matter - Kirchoff s Laws The Wave Nature of Electro-Magnetic Radiation Visible light is just

More information

Chapter 4 Spectroscopy

Chapter 4 Spectroscopy Chapter 4 Spectroscopy The beautiful visible spectrum of the star Procyon is shown here from red to blue, interrupted by hundreds of dark lines caused by the absorption of light in the hot star s cooler

More information

Discussion Review Test #2. Units 12-19: (1) (2) (3) (4) (5) (6)

Discussion Review Test #2. Units 12-19: (1) (2) (3) (4) (5) (6) Discussion Review Test #2 Units 12-19: (1) (2) (3) (4) (5) (6) (7) (8) (9) Galileo used his observations of the changing phases of Venus to demonstrate that a. the sun moves around the Earth b. the universe

More information

A World of Dust. Bare-Eye Nebula: Orion. Interstellar Medium

A World of Dust. Bare-Eye Nebula: Orion. Interstellar Medium Interstellar Medium Physics 113 Goderya Chapter(s): 10 Learning Outcomes: A World of Dust The space between the stars is not completely empty, but filled with very dilute gas and dust, producing some of

More information

In class quiz - nature of light. Moonbow with Sailboats (Matt BenDaniel)

In class quiz - nature of light. Moonbow with Sailboats (Matt BenDaniel) In class quiz - nature of light Moonbow with Sailboats (Matt BenDaniel) Nature of light - review Light travels at very high but finite speed. Light is electromagnetic wave characterized by wavelength (or

More information

SPECTROSCOPY PRELAB. 2) Name the 3 types of spectra and, in 1 sentence each, describe them.

SPECTROSCOPY PRELAB. 2) Name the 3 types of spectra and, in 1 sentence each, describe them. NAME: SPECTROSCOPY PRELAB 1) What is a spectrum? 2) Name the 3 types of spectra and, in 1 sentence each, describe them. a. b. c. 3) Use Wien s law to calculate the surface temperature of the star Alnilam

More information

hf = E 1 - E 2 hc = E 1 - E 2 λ FXA 2008 Candidates should be able to : EMISSION LINE SPECTRA

hf = E 1 - E 2 hc = E 1 - E 2 λ FXA 2008 Candidates should be able to : EMISSION LINE SPECTRA 1 Candidates should be able to : EMISSION LINE SPECTRA Explain how spectral lines are evidence for the existence of discrete energy levels in isolated atoms (i.e. in a gas discharge lamp). Describe the

More information

Chapter 11 Review. 1) Light from distant stars that must pass through dust arrives bluer than when it left its star. 1)

Chapter 11 Review. 1) Light from distant stars that must pass through dust arrives bluer than when it left its star. 1) Chapter 11 Review TRUE/FALSE. Write 'T' if the statement is true and 'F' if the statement is false. 1) Light from distant stars that must pass through dust arrives bluer than when it left its star. 1)

More information

Astronomy 1 Winter 2011

Astronomy 1 Winter 2011 Astronomy 1 Winter 2011 Lecture 8; January 24 2011 Previously on Astro 1 Light as a wave The Kelvin Temperature scale What is a blackbody? Wien s law: λ max (in meters) = (0.0029 K m)/t. The Stefan-Boltzmann

More information

Light & Atoms. Electromagnetic [EM] Waves. Light and several other forms of radiation are called electromagnetic waves or electromagnetic radiation.

Light & Atoms. Electromagnetic [EM] Waves. Light and several other forms of radiation are called electromagnetic waves or electromagnetic radiation. Light & Atoms Electromagnetic [EM] Waves Light and several other forms of radiation are called electromagnetic waves or electromagnetic radiation. These have both and electric part and a magnetic part

More information

Telescopes have Three Powers

Telescopes have Three Powers Telescopes have Three Powers 1. Light Gathering Power: The ability to collect light 2. Resolving Power: The ability to see fine details 3. Magnifying Power: The ability to make objects look bigger Pizzas!!!

More information

Next Homework Due Oct. 9. Coming up: The Sun (Chapter 10)

Next Homework Due Oct. 9. Coming up: The Sun (Chapter 10) Today Summary of Chapter 3: Light All of Chapter 4: Spectra & Atoms Optional: Ast. Toolbox 4-2 Optional: Stephan-Boltzmann Law Next Homework Due Oct. 9 Coming up: The Sun (Chapter 10) Resolving Power:

More information

Light or the Electromagnetic spectrum.

Light or the Electromagnetic spectrum. Light or the Electromagnetic spectrum www.nasa.gov Diffraction and Light When passed through a prism or grating, light is separated into its component wavelengths This looks like a rainbow in visible light

More information

Clicker Question: Clicker Question: What is the expected lifetime for a G2 star (one just like our Sun)?

Clicker Question: Clicker Question: What is the expected lifetime for a G2 star (one just like our Sun)? How Long do Stars Live (as Main Sequence Stars)? A star on Main Sequence has fusion of H to He in its core. How fast depends on mass of H available and rate of fusion. Mass of H in core depends on mass

More information

Intro to Galaxies Light and Atoms - I

Intro to Galaxies Light and Atoms - I Astrophysics Study of Light Study of Atoms Intro to Galaxies Light and Atoms - I 1 Atomic Physics elements: substances which cannot be broken down into simpler substances atom : smallest unit of an element

More information

What is LIGHT? Reading Question

What is LIGHT? Reading Question Reading Question What is LIGHT? A. Light is a wave, like sound only much faster. B. Light is like little particles. Each one is a photon. C. Light is the absence of dark. D. A kind of energy we model with

More information

AS 101: Day Lab #2 Summer Spectroscopy

AS 101: Day Lab #2 Summer Spectroscopy Spectroscopy Goals To see light dispersed into its constituent colors To study how temperature, light intensity, and light color are related To see spectral lines from different elements in emission and

More information

Today. Spectra. Thermal Radiation. Wien s Law. Stefan-Boltzmann Law. Kirchoff s Laws. Emission and Absorption. Spectra & Composition

Today. Spectra. Thermal Radiation. Wien s Law. Stefan-Boltzmann Law. Kirchoff s Laws. Emission and Absorption. Spectra & Composition Today Spectra Thermal Radiation Wien s Law Stefan-Boltzmann Law Kirchoff s Laws Emission and Absorption Spectra & Composition Spectrum Originally, the range of colors obtained by passing sunlight through

More information

The Main Point. How do light and matter interact? Lecture #7: Radiation and Spectra II. How is light absorbed and emitted?

The Main Point. How do light and matter interact? Lecture #7: Radiation and Spectra II. How is light absorbed and emitted? Lecture #7: Radiation and Spectra II How is light absorbed and emitted? Models of Atomic Structure. Formation of Spectral Lines. Doppler Shift. Applications in Solar System Studies Detecting gaseous phases

More information

Stars, Galaxies & the Universe Lecture Outline

Stars, Galaxies & the Universe Lecture Outline Stars, Galaxies & the Universe Lecture Outline A galaxy is a collection of 100 billion stars! Our Milky Way Galaxy (1)Components - HII regions, Dust Nebulae, Atomic Gas (2) Shape & Size (3) Rotation of

More information

Lights. And God said, "Let there be light"; and there was light. And God saw that the light was good; (Bible: Genesis I)

Lights. And God said, Let there be light; and there was light. And God saw that the light was good; (Bible: Genesis I) Lights Astronomy is based on observing lights from celestial bodies. And God said, "Let there be light"; and there was light. And God saw that the light was good; (Bible: Genesis I) Cat's Eye planetary

More information

Name: Partner(s): 1102 or 3311: Desk # Date: Spectroscopy Part I

Name: Partner(s): 1102 or 3311: Desk # Date: Spectroscopy Part I Name: Partner(s): 1102 or 3311: Desk # Date: Spectroscopy Part I Purpose Investigate Kirchhoff s Laws for continuous, emission and absorption spectra Analyze the solar spectrum and identify unknown lines

More information

Physics 1C Lecture 29A. Finish off Ch. 28 Start Ch. 29

Physics 1C Lecture 29A. Finish off Ch. 28 Start Ch. 29 Physics 1C Lecture 29A Finish off Ch. 28 Start Ch. 29 Particle in a Box Let s consider a particle confined to a one-dimensional region in space. Following the quantum mechanics approach, we need to find

More information

Chapter 5 Light and Matter: Reading Messages from the Cosmos. How do we experience light? Colors of Light. How do light and matter interact?

Chapter 5 Light and Matter: Reading Messages from the Cosmos. How do we experience light? Colors of Light. How do light and matter interact? Chapter 5 Light and Matter: Reading Messages from the Cosmos How do we experience light? The warmth of sunlight tells us that light is a form of energy We can measure the amount of energy emitted by a

More information

high energy state for the electron in the atom low energy state for the electron in the atom

high energy state for the electron in the atom low energy state for the electron in the atom Atomic Spectra Objectives The objectives of this experiment are to: 1) Build and calibrate a simple spectroscope capable of measuring wavelengths of visible light. 2) Measure several wavelengths of light

More information

How does your eye form an Refraction

How does your eye form an Refraction Astronomical Instruments Eyes and Cameras: Everyday Light Sensors How does your eye form an image? How do we record images? How does your eye form an image? Refraction Refraction is the bending of light

More information

Midterm Results. The Milky Way in the Infrared. The Milk Way from Above (artist conception) 3/2/10

Midterm Results. The Milky Way in the Infrared. The Milk Way from Above (artist conception) 3/2/10 Lecture 13 : The Interstellar Medium and Cosmic Recycling Midterm Results A2020 Prof. Tom Megeath The Milky Way in the Infrared View from the Earth: Edge On Infrared light penetrates the clouds and shows

More information

aka Light Properties of Light are simultaneously

aka Light Properties of Light are simultaneously Today Interaction of Light with Matter Thermal Radiation Kirchhoff s Laws aka Light Properties of Light are simultaneously wave-like AND particle-like Sometimes it behaves like ripples on a pond (waves).

More information

ASTRO Fall 2012 LAB #7: The Electromagnetic Spectrum

ASTRO Fall 2012 LAB #7: The Electromagnetic Spectrum ASTRO 1050 - Fall 2012 LAB #7: The Electromagnetic Spectrum ABSTRACT Astronomers rely on light to convey almost all of the information we have on distant astronomical objects. In addition to measuring

More information

Susan Cartwright Our Evolving Universe 1

Susan Cartwright Our Evolving Universe 1 Atoms and Starlight Why do the stars shine? planets shine by reflected sunlight but what generates the Sun s light? What does starlight tell us about the stars? their temperature their chemical composition

More information

Lecture 6: The Physics of Light, Part 1. Astronomy 111 Wednesday September 13, 2017

Lecture 6: The Physics of Light, Part 1. Astronomy 111 Wednesday September 13, 2017 Lecture 6: The Physics of Light, Part 1 Astronomy 111 Wednesday September 13, 2017 Reminders Star party tonight! Homework #3 due Monday Exam #1 Monday, September 25 The nature of light Look, but don t

More information

Prentice Hall EARTH SCIENCE

Prentice Hall EARTH SCIENCE Prentice Hall EARTH SCIENCE Tarbuck Lutgens Chapter 24 Studying the Sun 24.1 The Study of Light Electromagnetic Radiation Electromagnetic radiation includes gamma rays, X-rays, ultraviolet light, visible

More information

Energy. mosquito lands on your arm = 1 erg. Firecracker = 5 x 10 9 ergs. 1 stick of dynamite = 2 x ergs. 1 ton of TNT = 4 x ergs

Energy. mosquito lands on your arm = 1 erg. Firecracker = 5 x 10 9 ergs. 1 stick of dynamite = 2 x ergs. 1 ton of TNT = 4 x ergs Energy mosquito lands on your arm = 1 erg Firecracker = 5 x 10 9 ergs 1 stick of dynamite = 2 x 10 13 ergs 1 ton of TNT = 4 x 10 16 ergs 1 atomic bomb = 1 x 10 21 ergs Magnitude 8 earthquake = 1 x 10 26

More information

Deducing Temperatures and Luminosities of Stars (and other objects ) Electromagnetic Fields. Sinusoidal Fields

Deducing 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 information

Physics Homework Set I Su2015

Physics Homework Set I Su2015 1) The particles which enter into chemical reactions are the atom's: 1) _ A) protons. B) positrons. C) mesons. D) electrons. E) neutrons. 2) Which of the following type of electromagnetic radiation has

More information

LIGHT. Question. Until very recently, the study of ALL astronomical objects, outside of the Solar System, has been with telescopes observing light.

LIGHT. Question. Until very recently, the study of ALL astronomical objects, outside of the Solar System, has been with telescopes observing light. LIGHT Question Until very recently, the study of ALL astronomical objects, outside of the Solar System, has been with telescopes observing light. What kind of information can we get from light? 1 Light

More information

Chapter 5 Light and Matter: Reading Messages from the Cosmos

Chapter 5 Light and Matter: Reading Messages from the Cosmos Chapter 5 Light and Matter: Reading Messages from the Cosmos 5.1 Light in Everyday Life Our goals for learning How do we experience light? How do light and matter interact? How do we experience light?

More information

A100H Exploring the Universe: The interaction of light and matter. Martin D. Weinberg UMass Astronomy

A100H Exploring the Universe: The interaction of light and matter. Martin D. Weinberg UMass Astronomy A100H Exploring the Universe: The interaction of light and matter Martin D. Weinberg UMass Astronomy astron100h-mdw@courses.umass.edu February 11, 2016 Read: Chap 5 02/11/16 slide 1 Exam #1: Thu 18 Feb

More information

The Birth Of Stars. How do stars form from the interstellar medium Where does star formation take place How do we induce star formation

The Birth Of Stars. How do stars form from the interstellar medium Where does star formation take place How do we induce star formation Goals: The Birth Of Stars How do stars form from the interstellar medium Where does star formation take place How do we induce star formation Interstellar Medium Gas and dust between stars is the interstellar

More information

Chapter 5: Light and Matter: Reading Messages from the Cosmos

Chapter 5: Light and Matter: Reading Messages from the Cosmos Chapter 5 Lecture Chapter 5: Light and Matter: Reading Messages from the Cosmos Light and Matter: Reading Messages from the Cosmos 5.1 Light in Everyday Life Our goals for learning: How do we experience

More information

APAS Laboratory { PAGE } Spectroscopy SPECTROSCOPY

APAS Laboratory { PAGE } Spectroscopy SPECTROSCOPY SPECTROSCOPY SYNOPSIS: In this lab you will eplore different types of emission spectra, calibrate a spectrometer using the spectrum of a known element, and use your calibration to identify an unknown element.

More information

Atomic Emission Spectra

Atomic Emission Spectra Atomic Emission Spectra Objectives The objectives of this laboratory are as follows: To build and calibrate a simple meter-stick spectroscope that is capable of measuring wavelengths of visible light.

More information

9/16/08 Tuesday. Chapter 3. Properties of Light. Light the Astronomer s Tool. and sometimes it can be described as a particle!

9/16/08 Tuesday. Chapter 3. Properties of Light. Light the Astronomer s Tool. and sometimes it can be described as a particle! 9/16/08 Tuesday Announce: Observations? Milky Way Center movie Moon s Surface Gravity movie Questions on Gravity from Ch. 2 Ch. 3 Newton Movie Chapter 3 Light and Atoms Copyright (c) The McGraw-Hill Companies,

More information

Earlier we learned that hot, opaque objects produce continuous spectra of radiation of different wavelengths.

Earlier we learned that hot, opaque objects produce continuous spectra of radiation of different wavelengths. Section7: The Bohr Atom Earlier we learned that hot, opaque objects produce continuous spectra of radiation of different wavelengths. Continuous Spectrum Everyone has seen the spectrum produced when white

More information

λ is a distance, so its units are m, cm, or mm, etc.

λ is a distance, so its units are m, cm, or mm, etc. Electromagnetic Radiation (How we get most of our information about the cosmos) Radiation travels as waves. Waves carry information and energy. Properties of a wave Examples of electromagnetic radiation:

More information

The Nature of Light. We have a dual model

The Nature of Light. We have a dual model Light and Atoms Properties of Light We can come to understand the composition of distant bodies by analyzing the light they emit This analysis can tell us about the composition as well as the temperature

More information

Newton s Laws of Motion

Newton s Laws of Motion Newton s Laws of Motion #1: A body continues at rest or in uniform motion in a straight line unless acted upon by a force. Why doesn t the soccer ball move on its own? What causes a soccer ball to roll

More information

Chemistry is in the electrons

Chemistry is in the electrons Chemistry is in the electrons Electronic structure arrangement of electrons in atom Two parameters: Energy Position The popular image of the atom is incorrect: electrons are not miniature planets orbiting

More information

Chapter 11 The Formation of Stars

Chapter 11 The Formation of Stars Chapter 11 The Formation of Stars A World of Dust The space between the stars is not completely empty, but filled with very dilute gas and dust, producing some of the most beautiful objects in the sky.

More information

Chapter 5 Light and Matter: Reading Messages from the Cosmos. 5.1 Light in Everyday Life. How do we experience light?

Chapter 5 Light and Matter: Reading Messages from the Cosmos. 5.1 Light in Everyday Life. How do we experience light? Chapter 5 Light and Matter: Reading Messages from the Cosmos 5.1 Light in Everyday Life Our goals for learning: How do we experience light? How do light and matter interact? How do we experience light?

More information

Chapter 28. Atomic Physics

Chapter 28. Atomic Physics Chapter 28 Atomic Physics Quantum Numbers and Atomic Structure The characteristic wavelengths emitted by a hot gas can be understood using quantum numbers. No two electrons can have the same set of quantum

More information

10/27/2017 [pgs ]

10/27/2017 [pgs ] Objectives SWBAT explain the relationship between energy and frequency. SWBAT predict the behavior of and/or calculate quantum and photon energy from frequency. SWBAT explain how the quantization of energy

More information

Chapter 8. Spectroscopy. 8.1 Purpose. 8.2 Introduction

Chapter 8. Spectroscopy. 8.1 Purpose. 8.2 Introduction Chapter 8 Spectroscopy 8.1 Purpose In the experiment atomic spectra will be investigated. The spectra of three know materials will be observed. The composition of an unknown material will be determined.

More information

LIFE CYCLE OF A STAR

LIFE CYCLE OF A STAR LIFE CYCLE OF A STAR First stage = Protostar PROTOSTAR Cloud of gas and dust many light-years across Gravity tries to pull the materials together Eventually, at the center of the ball of dust and gas,

More information

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

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

More information

= λ. Light: The Cosmic Messenger. Continuing Topics for Today 1/24/17. Your account on Mastering Astronomy. ASTR 1040 Stars & Galaxies

= λ. Light: The Cosmic Messenger. Continuing Topics for Today 1/24/17. Your account on Mastering Astronomy. ASTR 1040 Stars & Galaxies REMINDER Your account on Mastering Astronomy ASTR 1040 Stars & Galaxies SDO: Post-flare ejection from solar surface Prof. Juri Toomre TAs: Piyush Agrawal, Connor Bice Lecture 3 Tues 24 Jan 2017 zeus.colorado.edu/astr1040-toomre

More information

The Theory of Electromagnetism

The Theory of Electromagnetism Notes: Light The Theory of Electromagnetism James Clerk Maxwell (1831-1879) Scottish physicist. Found that electricity and magnetism were interrelated. Moving electric charges created magnetism, changing

More information

Physics Homework Set 2 Sp 2015

Physics Homework Set 2 Sp 2015 1) A large gas cloud in the interstellar medium that contains several type O and B stars would appear to us as 1) A) a reflection nebula. B) a dark patch against a bright background. C) a dark nebula.

More information

Next Homework Due March 6. Coming up: The Sun (Chapter 10)

Next Homework Due March 6. Coming up: The Sun (Chapter 10) Today Summary of Chapter 3: Light All of Chapter 4: Spectra & Atoms Optional: Ast. Toolbox 4-2 Optional: Stephan-Boltzmann Law Next Homework Due March 6 Coming up: The Sun (Chapter 10) Extra Credit Astro-talks:

More information

c = l Light: The Cosmic Messenger 1/23/18

c = l Light: The Cosmic Messenger 1/23/18 Reading for today s and Thur class: ASTR 1040 Stars & Galaxies SDO: Post-flare ejection from solar surface Prof. Juri Toomre TAs: Peri Johnson, Ryan Horton Lecture 3 Tues 23 Jan 2018 zeus.colorado.edu/astr1040-toomre

More information

Today. Kirchoff s Laws. Emission and Absorption. Stellar Spectra & Composition. Doppler Effect & Motion. Extrasolar Planets

Today. Kirchoff s Laws. Emission and Absorption. Stellar Spectra & Composition. Doppler Effect & Motion. Extrasolar Planets Today Kirchoff s Laws Emission and Absorption Stellar Spectra & Composition Doppler Effect & Motion Extrasolar Planets Three basic types of spectra Continuous Spectrum Intensity Emission Line Spectrum

More information

ASTR 101 Introduction to Astronomy: Stars & Galaxies

ASTR 101 Introduction to Astronomy: Stars & Galaxies ASTR 101 Introduction to Astronomy: Stars & Galaxies If your clicker grade on BlackBoard is 0 and you have been in class, please send your clicker # to TA Cameron Clarke for checking The Milky Way Size

More information

General Physics (PHY 2140)

General Physics (PHY 2140) General Physics (PHY 140) Lecture 33 Modern Physics Atomic Physics Atomic spectra Bohr s theory of hydrogen http://www.physics.wayne.edu/~apetrov/phy140/ Chapter 8 1 Lightning Review Last lecture: 1. Atomic

More information

Light! Lecture 3, Oct. 8! Astronomy 102, Autumn 2009! Oct. 8, 2009 #1. Astronomy 102, Autumn 2009, E. Agol & J. Dalcanton U.W.

Light! Lecture 3, Oct. 8! Astronomy 102, Autumn 2009! Oct. 8, 2009 #1. Astronomy 102, Autumn 2009, E. Agol & J. Dalcanton U.W. Light! Lecture 3, Oct. 8! Astronomy 102, Autumn 2009! Oct. 8, 2009 #1 Questions of the Day! I. What is light?! II. What are the wave/particle properties of light?! III. How do energy and wavelength vary

More information

How does your eye form an Refraction

How does your eye form an Refraction Astronomical Instruments and : Everyday Light Sensors How does your eye form an image? How do we record images? How does your eye form an image? Refraction Refraction is the of light Eye uses refraction

More information

Buy-back points tallied and added: 750 points bought-back. Last Withdrawal date: this friday, Oct 31st.

Buy-back points tallied and added: 750 points bought-back. Last Withdrawal date: this friday, Oct 31st. Announcements HW #3: Available online now. Due in 1 week, Nov 3rd, 11pm. Buy-back points tallied and added: 750 points bought-back. Last Withdrawal date: this friday, Oct 31st. Evening Observing: next

More information

HOMEWORK - Chapter 4 Spectroscopy

HOMEWORK - Chapter 4 Spectroscopy Astronomy 10 HOMEWORK - Chapter 4 Spectroscopy 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

More information

Lecture 7. Outline. ASTR 111 Section 002. Discuss Quiz 5 Light. Light travels through empty space at a speed of 300,000 km/s

Lecture 7. Outline. ASTR 111 Section 002. Discuss Quiz 5 Light. Light travels through empty space at a speed of 300,000 km/s Lecture 7 ASTR 111 Section 002 Outline Discuss Quiz 5 Light Suggested reading: Chapter 5.1-5.2 and 5.6-5.8 of textbook Light travels through empty space at a speed of 300,000 km/s In 1676, Danish astronomer

More information

Review 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 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 information

Atoms and Spectra October 8th, 2013

Atoms and Spectra October 8th, 2013 Atoms and Spectra October 8th, 2013 Announcements Second writing assignment due two weeks from today (again, on a news item of your choice). Be sure to make plans to visit one of the open observing nights

More information

The Bohr Model of the Atom

The Bohr Model of the Atom Unit 4: The Bohr Model of the Atom Properties of light Before the 1900 s, light was thought to behave only as a wave. Light is a type of electromagnetic radiation - a form of energy that exhibits wave

More information

Chapter 5 Light and Matter: Reading Messages from the Cosmos. What is light? Properties of Waves. Waves. The Electromagnetic Spectrum

Chapter 5 Light and Matter: Reading Messages from the Cosmos. What is light? Properties of Waves. Waves. The Electromagnetic Spectrum Chapter 5 Light and Matter: Reading Messages from the Cosmos What is light? Light is a form of radiant energy Light can act either like a wave or like a particle (photon) Spectrum of the Sun 1 2 Waves

More information

X Rays must be viewed from space used for detecting exotic objects such as neutron stars and black holes also observing the Sun.

X Rays must be viewed from space used for detecting exotic objects such as neutron stars and black holes also observing the Sun. 6/25 How do we get information from the telescope? 1. Galileo drew pictures. 2. With the invention of photography, we began taking pictures of the view in the telescope. With telescopes that would rotate

More information

Models of the Atom. Spencer Clelland & Katelyn Mason

Models of the Atom. Spencer Clelland & Katelyn Mason Models of the Atom Spencer Clelland & Katelyn Mason First Things First Electrons were accepted to be part of the atom structure by scientists in the1900 s. The first model of the atom was visualized as

More information

A100 Exploring the Universe: The Milky Way as a Galaxy. Martin D. Weinberg UMass Astronomy

A100 Exploring the Universe: The Milky Way as a Galaxy. Martin D. Weinberg UMass Astronomy A100 Exploring the Universe: The Milky Way as a Galaxy Martin D. Weinberg UMass Astronomy astron100-mdw@courses.umass.edu November 12, 2014 Read: Chap 19 11/12/14 slide 1 Exam #2 Returned and posted tomorrow

More information

Types of Spectra. How do spectrum lines form? 3/30/09. Electron cloud. Atom. Nucleus

Types of Spectra. How do spectrum lines form? 3/30/09. Electron cloud. Atom. Nucleus The electron should be thought of as a distribution or cloud of probability around the nucleus that on average behave like a point particle on a fixed circular path Types of Spectra How do spectrum lines

More information

Light and Matter: Reading Messages from the Cosmos. White light is made up of many different colors. Interactions of Light with Matter

Light and Matter: Reading Messages from the Cosmos. White light is made up of many different colors. Interactions of Light with Matter Chapter 5 Lecture The Cosmic Perspective Light and Matter: Reading Messages from the Cosmos 5.1 Light in Everyday Life Our goals for learning: How do we experience light? How do light and matter interact?

More information

Galaxies and the Universe. Our Galaxy - The Milky Way The Interstellar Medium

Galaxies and the Universe. Our Galaxy - The Milky Way The Interstellar Medium Galaxies and the Universe Our Galaxy - The Milky Way The Interstellar Medium Our view of the Milky Way The Radio Sky COBE Image of our Galaxy The Milky Way Galaxy - The Galaxy By Visual Observation

More information

chapter 31 Stars and Galaxies

chapter 31 Stars and Galaxies chapter 31 Stars and Galaxies Day 1:Technology and the Big Bang Studying the Stars A. Telescopes - Electromagnetic radiation emitted by stars and other objects include light, radio, and X-ray Space telescopes

More information

PHYS 160 Astronomy Test #2 Fall 2017 Version A

PHYS 160 Astronomy Test #2 Fall 2017 Version A PHYS 160 Astronomy Test #2 Fall 2017 Version A I. True/False (1 point each) Circle the T if the statement is true, or F if the statement is false on your answer sheet. 1. A blackbody emits all of its radiation

More information

ASTRONOMY. Chapter 5 RADIATION AND SPECTRA PowerPoint Image Slideshow

ASTRONOMY. Chapter 5 RADIATION AND SPECTRA PowerPoint Image Slideshow ASTRONOMY Chapter 5 RADIATION AND SPECTRA PowerPoint Image Slideshow FIGURE 5.1 Our Sun in Ultraviolet Light. This photograph of the Sun was taken at several different wavelengths of ultraviolet, which

More information

Interested in exploring science or math teaching as a career?

Interested in exploring science or math teaching as a career? Interested in exploring science or math teaching as a career? Start with Step 1: EDUC 2020 (1 credit) Real experience teaching real kids! No commitment to continue with education courses Registration priority

More information

Lecture 5: the Hydrogen Atom

Lecture 5: the Hydrogen Atom Lecture 5: the Hydrogen Atom 1. Hydrogen atom: energy levels in the Bohr model 2. Emission lines: atoms releasing energy as electrons fall from level to level 3. Absorption lines: electrons being bumped

More information

Chapter 6. Quantum Theory and the Electronic Structure of Atoms Part 1

Chapter 6. Quantum Theory and the Electronic Structure of Atoms Part 1 Chapter 6 Quantum Theory and the Electronic Structure of Atoms Part 1 The nature of light Quantum theory Topics Bohr s theory of the hydrogen atom Wave properties of matter Quantum mechanics Quantum numbers

More information