Astro 2,640-N

             The Stars and Galaxies

             Purdue (Fall 2024, MW)

                    bwoodahl@purdue.edu

                    (Don't Use Brightspace to contact me, use email link)

                    Office: LD 156-S, 278-9244

                    Class: LD 010 on Monday and Wednesday, 12:00 - 1:15

                    http://134.68.135.8/Astro2640

Gentle Reminder: Exam 3 (Wednesday, December 4)

• Last Exam on Wednesday, December 4th from 12:00 PM to 1:15 PM

• The Exam is NOT comprehensive (Yippee!), hence we call it "Exam 3"

• Be on time, no admittance after 12:15 PM (if late, you'll earn a zero)

• About 50 multiple-choice questions, review your notes following Exam 2 material

• Rememberize to bring a #2 pencil

• ''.. I brought my pencil, gimme something to write on, man ..'' OpScan sheets will be provided, pick one up when you enter

• The course ends after you turn-in your Exam 3, there is no final exam.

Exam 3 Study Guide

• Exam 3 Study Guide

Week 16 Images (Monday)

• Dark Energy

• Vacuum Energy Due to Virtual Pairs

• Lawrence Krauss (with S. Hawking): Quintessence, The Variable Vacuum Energy

• Small Scale Structure of Our Universe

Week 15 Image

• No Class on Monday. Enjoy your Thanksgiving Break!

Reminder: Take-Home Project, Due on Thursday Nov 21 by 5 PM

• Take-Home Project.pdf

Week 14 Images

• Radiation-Dominated Then Matter-Dominated

• Big Crunch

• The 3 Possible Global Geometries of the Universe

Week 13 Images

• Age Of Universe

• Big Bang Theory

• Stages of Expansion of Universe During Big Bang

• Evidence for the Big Bang Theory: Penzias and Wilson and their Microwave Antenna

• Spectrum of Microwave Radiation Closely Matches Big Bang Theory

• "High-Tech" Big Bang Detector in Your Home: Snowy Channel on an Antenna-Fed TV (1% is CMBR)

• Matter Types During the Expansion of Universe

• The Horizon Problem

• The Effects of Inflation on the Cosmic Horizon

• Inflation Theory Solves Horizon Problem

• The Four Forces (Again)

• Gravity: Binds Objects with Mass (Motorcycle's Front Wheel Overcomes Gravity)

• Electromagnetic: Binds Electrons to Protons to Form Atoms (Beryllium Atom)

• Weak: Quarks Change Into Other Quarks (Neutron Decay)

• Strong: Binds Quarks to Form Protons, Neutrons, and Nuclei (Helium Nucleus)

• Weinberg: Co-Developed the Electroweak Theory

• Feynman: A Genius Among Physicists

• Feynman Diagrams

• Feynman's Feynman Diagrams on Feynman's Van

Week 12 Images

• The Jets of Cygnus A (color enhanced, microwave frequencies)

• Looking for Quasars and Radio Galaxies: Australia's Telescope Compact Array (ATCA)

• Einstein During the Development of Special Relativity

• Supermassive Black Holes (SBHs) Power Quasars

• Blazars, Quasars, and Radio Galaxies

• Massive Star Collapses Forming Black Hole: Jets Along Rotation Axis Produce Gamma-Ray Long-Burst

• Gamma-Ray Short-Burst: Collision Involving Neutron Stars & Black Holes

• Einstein's Lambda: The Cosmological Constant

• Cosmological Constant Changes the Expansion of Universe

• Cosmological Redshift Due to Expansion of Space

Week 11 Images

• The Local Group, Big Players: Milky Way and Andromeda

• Galactic Rotation Curves of Nearby Galaxies

• Hubble's Plot: The Expansion of the Universe

• Hubble's Law

• A Globular Cluster in Milky Way: Omega Centauri (NGC5139), Visible by Unaided Eye

• LSS of Universe: Clusters & Superclusters that Neighbor the Milky Way (Near-Infrared Frequencies)

Exam 2 (Monday, October 28)

• 65 questions, multiple choice, review your notes following the Exam 1 material

• Rememberize to bring a #2 pencil

• ''.. I brought my pencil, gimme something to write on, man ..'' OpScan sheets will be provided, pick one up when you enter

Exam 2 Study Guide

• Exam 2 Study Guide

Week 10 Images

• Edwin Hubble: Determined M31 Was a Galaxy 2 Million Light-Years Away

• Milky Way Galaxy (Edge View)

• Supermassive Black Hole

• Synchrotron Radiation

• Solid Body Rotation

• Keplerian Rotation

• Differential Rotation (Typical Galaxy)

• Dark Matter (Imagine that the green/yellow/orange strands are dark and you cannot see them.)

• Grand Design Spiral Galaxy (M101)

• Flocculent Spiral Galaxy (NGC4414)

• Grand Design Spiral Galaxy (M81)

• Spiral Structure of Milky Way Galaxy -- possibly a "Barred-Spiral"

• Barred Spiral Galaxy (NGC1300)

• Elliptical Galaxy (M87)

• Lenticular Galaxy (NGC3115)

• Irregular Galaxy (NGC1068)

Take-Home Project (Due: Thursday, Nov 21 at 5 PM)

• Take-Home Project.pdf

Quiz 6 (Wednesday, October 16)

• 4 questions, multiple choice, review your notes from the last four lectures

Week 9 Images

• The Geometry of a Black Hole

• Einstein: General Relativity

• Postulate of General Relativity: Equivalence Principle

• Matter Warps Space and Time

• Gravitational Redshift of Light Leaving Neutron Star

• Perihelion (and Aphelion) of Planet

• Shift of the Perihelion of Mercury

• Superstring Theory

• Stephen Hawking: Primordial (Micro) Black Holes

• Schwarzschild: Discovered Event Horizon of Black Hole (Schwarzschild Radius)

• "No Hair" Theorem of a Black Hole

• The Kerr Black Hole is Rotating

• Falling Into a Black Hole: OUCH

• Hawking Radiation: Black Holes Eventually Evaporate

• General Relativity Allows for Wormhole Solutions for Faster than Light Travel

• "Back To The Past": General Relativity Allows for Wormhole Solutions for Time Travel

Final Exam Schedule

• Purdue Indianapolis has released the date/time for our Final

• Final Exam: in LE 105 on Tuesday, Dec 10 starting at 10:30 AM

• Pencil this into your Calendar.

• However, I might change it to just an Exam 3 during the last week of lecture

10 Bonus Points Opportunity

• In no less than 1000 words, TYPED, submitted as a PDF (not Word or txt, etc.) to bwoodahl@purdue.edu, explain in your own words the "Unruh Effect" and its connection to black holes. Make sure you include your full name, the due date is Friday Nov 15th at 5:00 PM.

Week 8 Images (Wednesday only)

• The Multiple Layers of a High-Mass SuperGiant

• Death of a High-Mass Star: Supernova (Crab Nebula Produced in 1054 AD)

• Visible Remnants of Supernova: Nebula (Eskimo Nebula)

• Neutron Star

• Pulsar

Quiz 5 (Wednesday, October 2)

• 4 questions, multiple choice, review your notes from the last two lectures

Week 7 Images

• On The Road to Giantdom

• It's Better To Burn Out, Than Fade Away...

• Main-Sequence Versus Giant

• The Helium Flash Turning Point

• Hydrogen-Shell Burning Star

• Recombination Photons During Helium Shell Flashes: Double-Shell Red Giant

• Nova

Week 6 Images

• An Interstellar Medium Containing Carbon Monoxide (Radio Frequencies)

• Cold, Molecular, Star-Forming Cloud (Infrared Frequencies)

• Interstellar Dust Grain: Easily Scatters Blue Light

• Pink Floyd DSOM: Scattering of Light: Violet and Blue Scatter More (Bending Angle Greater) Than Red and Orange

• Blue Sky and Red Dawn on Earth

• Atmospheric Scattering of Light: Blue Daytime Skies and Red Dawn

• Gravitational Forces Generate Lumpy Protostar

• Birth Process of Star

• Artistic Rendition of Star Birth

• Main-Sequence Lifetimes

• Red Dwarfs

Exam 1 (Monday, September 23)

• 65 questions, multiple choice, review all your notes

• Covers all lectures

• In our normal room, also bring a #2 (HB) pencil

• ''.. I brought my pencil, gimme something to write on, man ..'' OpScan sheets will be provided, pick one up when you enter

Exam 1 Study Guide

• Exam 1 Study Guide

Quiz 4 (Wednesday, September 18)

• 4 questions, multiple choice, review your notes from the last five lectures

Week 5 Images

• Absolute Brightness or Luminosity Versus Apparent Brightness

• Light From Stars Obeys an "Inverse Square Law"

• The Hertzsprung-Russell or H-R Diagram

• H-R Diagram with the Instability Strip

• Traditional H-R Diagram with the Absolute Magnitude Scale (on right-hand side)

• Example: Altair

• Our Sun as Red Giant

• The Red SuperGiant Betelgeuse (Hubble): Diameter is Larger than Jupiter's Orbit Around the Sun

• Comparing Sizes: SuperGiants to White Dwarfs

Quiz 3 (Wednesday, September 11)

• 4 questions, multiple choice, review your notes from the past two weeks

• In particular for 2 of the questions, know duality of light and the physicist that developed the 4 equations of EM theory

Week 4 Images

• Photon (wavy line) Being Absorbed by Atom -> Electron (solid blue line) Jumps Up into Higher Orbit

• Atom Emitting a Photon (wavy line) -> Electron (solid blue line) Jumps Down into Lower Orbit

• Sound Produced by Stationary Source

• Sound Produced by Moving Source: Doppler Effect

• Doppler Effect on Spectra: Redshifting and Blueshifting

• Our Visible Universe is Home to 10²² Stars

• Proxima Centauri

• Stellar Parallax: Determines Distance to Nearby Stars

• Stars with Higher Surface Temperatures Emit Mostly Shorter Wavelengths

• Spectral Types: O, B, A, F, G, K, M

• Binary Star Systems

• Mass Information from Doppler Shift of Spectra from a Binary Star System

Quiz 2 (Wednesday, September 4)

• 4 questions, multiple choice, review your notes from the past two weeks

• In particular, look over proton-proton chain and the four forces -- notably the strong and electromagnetic

Week 3 Images

• Duality of Light: Light Is Both a Wave and a Particle

• Particle Aspect of Light: Einstein's Photoelectric Effect

• Wave Aspect of Light: Young's Interference Patterns

• James Maxwell (in 1860): Father of the Famous Maxwell Equations Governing the Behavior of Light

• Wilhelm Wien (in 1893): Developed Theory (Wien's Law) for the Brightest Color of a Blackbody Radiator

• Blackbody Radiators Produce Signature Intensity Profiles

• Spectra of Helium, Sodium, and Neon

• Absorption Spectra

• Niels Bohr (sitting with Einstein): Architect of Modern Theory of Atomic Physics

Quiz 1 (Wednesday, August 28)

• 4 questions, multiple choice, review your notes from the last week and Monday's lectures

• Know: temperature scales: Kelvin (absolute), Fahrenheit, Celsius; Galileo (first to watch sunspots -- rotation rate); multiplying large numbers; and temperature of the Sun at various locations

Week 2 Images

• Atoms: The Building Blocks of Nature

• Water Molecule: Two Hydrogen Atoms and One Oxygen Atom

• The 4 Fundamental Interactions (Forces)

• The 4 Fundamental Forces Occur Only at Moderately Low Temperatures

• Nuclear Reactions: Fission and Fusion

• Sun's Proton-Proton Chain Fusion Reaction (4 Protons Produce Helium + Energy)

• Details of the Proton-Proton Chain

• Movie of the Proton-Proton Chain

• Sun In Hydrostatic Equilibrium

• Sun's Inner Structure (Layers Not Necessarily To Scale)

• Neutrino (Artistic Rendition)

• Homestake Neutrino Detector in South Dakota

• Ray Davis, 2002 Nobel Prize in Physics for the Detection of Cosmic Neutrinos During 1960's

• Quarks Fundamental Particles, Three Quarks in Every Proton and Neutron

• Einstein (in 1904): Speed Of Light is the "Speed Limit of Our Universe"

• Light Waves Possess Wavelength and Frequency

• Visible Light is a Small Part of the Entire Electromagnetic Spectrum

• Isaac Newton (in 1670): White Light Contains All the Visible Colors (Visible Frequencies)

Week 1 Images

• The Big Picture (actually it's a somewhat small picture)

• Examples of Some Big Numbers

• Astronomy, the Oldest of the Sciences, 5000 Years Old: Stonehenge

• Approaching Modernity: Galileo Galilei's 1610 AD Notebook Page (Who Needs Computers?)

• Our Sun (oh was it angry when we took its picture)

• Temperature: Simply a Measurement of Particle Velocity

• Authors of the ill-fated "chemical reactions due to gravitational collapse" theory of Sun: Kelvin and Helmholtz

• Sunspot Formations

• Magnetic Field Lines "Trap" Moving Charged Particles (Thus They Spiral)

• Solar Prominences (Filaments)

• Solar Flare

• Coronal Mass Ejection (Orange Disc is Photosphere, Red Disc is Chromosphere, X-Ray Photography)

Course Information

• Syllabus (PDF).   Please print and keep with your notes.

• Schedule (PDF).   Please print and keep with your notes.

• These documents will likely change/update throughout the semester.  Please check that you have the latest versions.

Amazon.com Links for Optional Textbooks (New and Used)

• The Cosmic Perspective: Stars and Galaxies (7th Edition)

• The Cosmic Perspective, Both Volumes (7th Edition)

• The Cosmic Perspective, Both Volumes (6th Edition)

• Amazon.com Textbook Rentals

Department of Physics & Astronomy - Updated on November 22, 2024 at 12:02 PM EST