Astrophysics
Stars, galaxies and the physics used to understand them: astronomical scales and units, the inverse-square law and order-of-magnitude reasoning, with the Sun's luminosity, mass, radius and temperature worked out from four measurements; the celestial sphere, horizon and equatorial coordinates, sidereal time, precession, proper motion and the aberration of starlight; telescopes and detectors across the electromagnetic spectrum, atmospheric windows, diffraction, seeing, adaptive optics, radio interferometry and the Event Horizon Telescope, CCDs and photon-counting signal-to-noise calculations; trigonometric parallax from Bessel to Gaia, apparent and absolute magnitudes, the distance modulus and extinction, and the distance ladder of Cepheid variables, the tip of the red giant branch and Type Ia supernovae; stellar spectra, effective temperatures, the Saha and Boltzmann equations, the spectral sequence and the Hertzsprung–Russell diagram; visual, spectroscopic and eclipsing binaries, the mass function and the mass–luminosity relation; stellar structure through hydrostatic equilibrium, the virial theorem, polytropes, radiative and convective transport, the Eddington limit, the proton–proton chain and CNO cycle, solar neutrinos and helioseismology; star formation and the Jeans mass, red giants, the helium flash, asymptotic giant branch stars, planetary nebulae, white dwarfs and the Chandrasekhar limit, and cluster ages; core-collapse and thermonuclear supernovae, Supernova 1987A, the origin of the elements, neutron stars and pulsars, black holes and gravitational waves; the structure of the Milky Way, rotation curves and the evidence for dark matter, spiral arms, galaxy types and quasars; exoplanet detection by radial velocity, transits, imaging and microlensing, the exoplanet census and habitable zones; and a capstone on the expanding universe, the cosmic microwave background, Big Bang nucleosynthesis, dark energy and the Hubble tension, with runnable Python examples throughout.
PHYS-430 Year 4 3 credits 12 lessons · 4 h 35 min ▶ Video lessons coming soon
Offered by HSM University · Physics
This is the Canadian version of this course. See the American version.
What you'll learn
- Use astronomical units of distance, mass and luminosity, the inverse-square law and order-of-magnitude reasoning to derive the Sun's basic properties from four measurements.
- Convert between horizon and equatorial coordinates using sidereal time and the hour angle, and explain precession, proper motion and aberration.
- Explain how telescopes gather and resolve light across the electromagnetic spectrum, apply the diffraction limit, and estimate exposure times from photon statistics.
- Measure distances with trigonometric parallax, the magnitude system and the distance modulus, and explain how Cepheids, the tip of the red giant branch and Type Ia supernovae extend the distance ladder.
- Infer stellar temperatures, compositions and radii from spectra using Wien's law, the Stefan–Boltzmann law and the Saha and Boltzmann equations, and interpret the Hertzsprung–Russell diagram.
- Determine stellar masses from visual, spectroscopic and eclipsing binaries, including the mass function, and apply the mass–luminosity relation.
- Apply hydrostatic equilibrium, the virial theorem, radiative and convective transport, the Eddington limit and nuclear reaction physics to explain the structure of stars.
- Describe star formation through the Jeans criterion, the evolution of low- and intermediate-mass stars to white dwarfs, the Chandrasekhar limit and the use of cluster turnoffs as clocks.
- Explain core-collapse and thermonuclear supernovae, the origin of the elements, and the physics of neutron stars, pulsars and black holes, including gravitational-wave observations.
- Describe the structure of the Milky Way and other galaxies, compute enclosed masses from rotation curves, and evaluate the evidence for dark matter.
- Compare the main methods of detecting exoplanets, interpret the exoplanet census, and compute equilibrium temperatures and habitable zones.
- Explain the evidence for the expanding universe, the cosmic microwave background, Big Bang nucleosynthesis and dark energy, and describe the Hubble tension and other open questions.
Course content
12 lessons · 4 h 35 min total · final exam
- 1 Why astrophysics: the universe as a physics laboratory 23 min · quiz
- 2 The sky and coordinates: positions, time and the celestial sphere 21 min · quiz
- 3 Telescopes, detectors and the electromagnetic spectrum 22 min · quiz
- 4 Distances: parallax, the magnitude system and the distance ladder 22 min · quiz
- 5 Stellar spectra, classification and the Hertzsprung–Russell diagram 21 min · quiz
- 6 Binary stars and stellar masses 23 min · quiz
- 7 Stellar structure: hydrostatic equilibrium, energy transport and nuclear burning 22 min · quiz
- 8 Stellar evolution: from the main sequence to giants and white dwarfs 24 min · quiz
- 9 Supernovae, neutron stars and black holes 26 min · quiz
- 10 The Milky Way and other galaxies: rotation curves and dark matter 23 min · quiz
- 11 Exoplanets: detection methods, demographics and habitability 24 min · quiz
- 12 Capstone: cosmology in brief — expansion, the cosmic microwave background and open questions 24 min · quiz
- E Final exam 20 questions
Requirements
Recommended background. You can start any course at any time.
Description
Stars, galaxies and the physics used to understand them: astronomical scales and units, the inverse-square law and order-of-magnitude reasoning, with the Sun's luminosity, mass, radius and temperature worked out from four measurements; the celestial sphere, horizon and equatorial coordinates, sidereal time, precession, proper motion and the aberration of starlight; telescopes and detectors across the electromagnetic spectrum, atmospheric windows, diffraction, seeing, adaptive optics, radio interferometry and the Event Horizon Telescope, CCDs and photon-counting signal-to-noise calculations; trigonometric parallax from Bessel to Gaia, apparent and absolute magnitudes, the distance modulus and extinction, and the distance ladder of Cepheid variables, the tip of the red giant branch and Type Ia supernovae; stellar spectra, effective temperatures, the Saha and Boltzmann equations, the spectral sequence and the Hertzsprung–Russell diagram; visual, spectroscopic and eclipsing binaries, the mass function and the mass–luminosity relation; stellar structure through hydrostatic equilibrium, the virial theorem, polytropes, radiative and convective transport, the Eddington limit, the proton–proton chain and CNO cycle, solar neutrinos and helioseismology; star formation and the Jeans mass, red giants, the helium flash, asymptotic giant branch stars, planetary nebulae, white dwarfs and the Chandrasekhar limit, and cluster ages; core-collapse and thermonuclear supernovae, Supernova 1987A, the origin of the elements, neutron stars and pulsars, black holes and gravitational waves; the structure of the Milky Way, rotation curves and the evidence for dark matter, spiral arms, galaxy types and quasars; exoplanet detection by radial velocity, transits, imaging and microlensing, the exoplanet census and habitable zones; and a capstone on the expanding universe, the cosmic microwave background, Big Bang nucleosynthesis, dark energy and the Hubble tension, with runnable Python examples throughout.
Part of the Science stream, typically taken in year 4.