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/

Exam 1 Study Guide

• Exam 1 Study Guide

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 Sep 12, 2025 at 1:02 PM EST