Astro A-105 (online)

             SERVER for Lecture Videos & Images

             The Stars and Galaxies

             Fall 2025, IU Indianapolis

                    bwoodahl@iu.edu

                    (For Canvas Messages, my replies may be slower. Use direct email link for faster replies.)

                    Office: LD 156-S, 278-9244

                    http://woodahl.physics.indianapolis.iu.edu/Astro105MW/

Week 12 (Nov 10 to Nov 14) Lecture Videos and Images

• "Gamma-Ray Bursters and Cosmological Constant" #22 Video Lecture

• "Age of Universe and the CMBR" #23 Video Lecture

• 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

• 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

Week 11 (Nov 3 to Nov 7) Lecture Videos and Images

• "Clusters and Hubble's Law" #20 Video Lecture

• "Quasars" #21 Video Lecture

• 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)

• 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

Exam 2 Study Guide

• Exam 2 Study Guide

Week 10 (Oct 27 to Oct 31) Lecture Video and Images

• "Types of Galaxies" #19 Video Lecture

• 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)

Week 9 (Oct 20 to Oct 24) Lecture Videos and Images

• "Hydrogen Spin-Flip Radiation" #17 Video Lecture

• "Supermassive Black Holes & Dark Matter" #18 Video Lecture

• 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.)

Week 8 (Oct 13 to Oct 17) Lecture Videos and Images

• "Black Holes" #15 Video Lecture

• "Stephen Hawking" #16 Video Lecture

• 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

• 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

Week 7 (Oct 6 to Oct 10) Lecture Videos and Images

• "Death of Low Mass Stars" #13 Video Lecture

• "Death of High Mass Stars" #14 Video Lecture

• 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

• 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

Week 6 (Sep 29 to Oct 3) Lecture Videos and Images

• "Main-Sequence Birth" #11 Video Lecture

• "Variable Stars" #12 Video Lecture

• 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 Study Guide

• Exam 1 Study Guide

Week 5 Lecture Videos and Images

• "Stellar Brightness and the H-R Diagram" #9 Video Lecture

• "Spectroscopic Parallax" #10 Video Lecture

• 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

Week 4 Lecture Videos and Images

• "Parallax Formula and Surface Temperatures" #7 Video Lecture

• "Stellar Mass" #8 Video Lecture

• 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

Week 3 Lecture Videos and Images

• "The Physics of Light" #5 Video Lecture

• "Spectra and the Doppler Effect" #6 Video Lecture

• 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

Week 2 Lecture Videos and Images

• "Proton-Proton Chain" #3 Video Lecture

• "The Solar Neutrino Problem" #4 Video Lecture

• 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 Lecture Videos and Images

• "Introduction to the Sun" #1 Video Lecture

• "Kelvin & Helmholtz Theory, Sun's Exterior" #2 Video Lecture

• 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).

• Schedule (PDF).

• These documents may change during 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

IUI Department of Physics - Updated on November 7, 2025 at 2:05 PM EST