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The Evolving Universe
summary of testable topics
| Lecture I - | Introduction |
| | Cosmic distances |
Astronomy as a dynamic discipline.
Influenced by cultural processes (e.g. Stonehenge, Greek and Arabic schools, Renaissance).
Astronomy and Astrophysics versus Astrology.
Naked-eye observations (Rising/setting of stars, constellations, eclipstic, planets, comets, meteors, eclipses, Milky Way).
Emptiness and dimensions of the Universe (powers of 10).
Finite, maximum speed of light.
Concept of light-day and light-year as a measure of distance.
The connection between space and time.
Motions of objects in the night sky.
| Lecture II - | Early developments in astronomy |
| | From a geocentric to a heliocentric world view |
| | Kepler's laws |
The role of astronomy in ancient cultures (temples, rites and rituals, practical uses).
Astrology as a (modern) socio-cultural phenomenon.
Shifting world views (archeo-astronomy, antiquity, scientific revolution).
Evidence for prehistoric interest in astronomy (monuments, artifacts).
Helical rise of Sirius, astronomical alignment of the pyramids.
Greek exploration of the Earth-Moon-Sun system.
Reasonings by Eratosthenes and Aristarchus (Earth circumsphere, relative sizes and distances).
From a geocentric to a heliocentric worldview.
Discoveries of Galileo Galilei (Moon mountains, Jupiter moons, phases of Venus).
Understanding the visibility of inner and outer planets.
Maximum elongations of Mercury and Venus.
Retrograde motions of Mars, Jupiter, Saturn.
Epicycles versus ellipitical orbits.
Understanding the three laws of Kepler.
Gravity as a fundamental force of nature (Newton, escape velocity, satellite orbits).
| Lecture III - | The heavens in motion |
| | Stars and Constellations |
| | Celestial coordinates and seasons |
The naming of stars.
Constellations and their cultural backgrounds.
Angular distances on the celestial sphere.
The night sky seen at different locations on Earth (celestial poles, circumpolar stars).
Equatorial coordinates (Celestial equator, Right Ascension, Declination, meridian, zenith, nadir).
Origin of the ecliptic/zodiac, tilt of Earth axis.
Equinoxes and solstices.
Other coordinate systems (no details).
Cause and consequences of Precession.
Understanding the analemma and its cuases.
The origin of the seasons.
(Familiarity with the Stellarium software)
| Lecture IV - | Earth and Moon |
| | Lunar and Solar Eclipses |
| | Time and Calendar |
Visibility of the Moon in the sky (phases, period, movement on the celestial sphere).
Resonance beween rotation and orbital period.
Sidereal versus Synodic periods.
Geometry of Lunar and Solar eclipses.
Consequences of tilt and ellipticity of Lunar orbit.
Understanding total, partial and angular eclipses (Umbra and Penumbra).
The role of Earth atmosphere during total Lunar eclipses.
Understanding the libration and analemma of the Moon.
Tides as caused by the Moon and Sun (spring and neap tides).
Understanding the origin of our calendar (day, week, month, year).
Understanding the need for leap years.
Sidereal times versus solar time.
Global properties of the Earth (core/mantle/crust, plate tectonics, density, atmosphere, magnetic field).
Global properties of the Moon (size, surface features, density, distribution of craters).
| Lecture V - | Electromagnetic radiation |
Light as an Electro-Magnetic phenomenon (coupling of electric and magnetic fields).
The wave/particle duality of light.
Early measurements of the speed of light.
Light as a wave (wavelength, frequency, energy).
Light as a particle.
The electromagnetic spectrum (rainbow).
Different manifestations of EM radiation (gamma-rays to radio waves).
Black Body radiation, Planck curve, Wien's law (continuum spectrum).
The electronic structure of atoms, the origin of spectral lines.
The spectral lines of an Hydrogen atom.
Radiation processes (emission, absorption, transmission, reflection).
Astrophysical information from a spectrum (temperature, chemical elements, density, pressure).
The Doppler effect: redshift and blueshift.
| Lecture VI - | Telescopes |
| | Observing techniques |
Earth atmosphere as a filter, atmospheric windows, need for space-based telescopes.
Basic functions of a telescope.
Refractor and reflector telescopes (advantages and disadvantages).
The magnification of an optical telescope.
The refraction of light (water, glass, atmosphere).
Chromatic aberration of lenses.
Light-collecting power.
Diffraction limit and angular resolution (wavelength and diameter).
Seeing and its cause.
The concept and advantages of adaptive optics.
Radio telescopes (single-dish, interferometry, resolution).
Complementarity of astronomical images from different telescopes.
Use of satellites to observe outside atmospheric windows.
The relevance of computer simulations (exploring time).
| Lectures VII & VIII - The Solar system - I & II |
Constituents of the Solar system:
Sun, different classes of planets and their moons (redefinition of a planet).
Asteroids, comets, meteoroids.
Oort cloud, Kuiper belt.
Structure of the Solar system:
Planetary orbits and the orientation of rotation axes of planets.
The formation of the Solar system (angular momentum, protoplanetary disk, dust, planetesimals).
Understanding the relation between the formation process and the structure of the Solar system.
Protoplanetary disk around other stars.
Detection of exoplanets.
Orbital and rotation periods of planets.
Definiton of the Astronomical Unit.
Consequences of Kepler's laws.
Inner versus outer planets (visibility, phases, retrograde motion).
Terrestrial versus Jovian planets (composition, size, distance from Sun).
Classical versus Dwarf planets (size, gravitational influence).
Location and extent of the Kuiper Belt and the Oort Cloud.
General properties of individual planets:
Physical properties (composition, size, density, surface temperatures, magnetic fields).
Atmospheric properties (presence, relative pressure, composition).
Geological properties (surface structures, plate tectonics, vulcanism, craters).
Specific characteristic properties (rings, rotation axis, liquids on/below surface).
Small Solar System Bodies:
Location of asteroids, comets and Trans-Neptunian Objects.
Differences between asteroids and comets (composition, size, orbits).
Understanding cometary tails (origin, development, orientation).
The origin of meteors.
| Lecture IX - | The Sun |
| | Introduction to the stars |
The Sun:
General properties (distance, size, mass, density, luminosity, surface temperature).
Energy source (nuclear fusion and the proton-proton cycle).
Hydrostatic equilibtium, the Sun as a dynamic system.
Radiation, convection and conduction to transport energy.
Structure of the atmosphere (photosphere, chromosphere, corona).
Understanding sunspots (temperature, umbra, penumbra, location on the Sun, relation to magnetic fields).
The Solar cycle, the butterfly diagram, cause of the Maunder minimum.
Granulation and convection.
Prominences and spicules in the chromosphere.
The Corona and the Solar wind (Coronal mass Ejections and the Aurora).
The Solar spectrum (temperature, absorption lines, spectral class, Luminosity Class).
Photometry:
The use of filters to estimate colours and temperatures.
Wien's law and Stefan-Boltzmann's law (luminosity, temperature and size/surface area).
The magnitude system (brightest and faintest objects).
Relation between luminosity and magnitudes.
Apparent versus Absolute magnitudes.
Definition of Absolute magnitude.
Stars:
Distances from parallax, definition of parsec.
Proper motions (time scales).
Spectral (sub)classes, temperatures and absorption lines (O-B-A-F-G-K-M).
Relation between colour, temperature and spectrum of a star.
The meaning and origin of Luminosity Classes or Pressure Classes I--V.
Concept of stellar dwafs versus giants.
Relation between luminosity, surface temperature and size.
The Hertzsprung-Russell diagram:
Luminosity (absolute magnitude) versus surface temperature (spectral type).
Location of the Main Sequence, Giants, Supergiants, White Dwarfs.
The range in mass, temperature, luminosity and size of stars.
Calculating distances from Luminosity Class, temperature and apparent magnitude.
| Lecture X - | Interstellar Matter |
| | Star Formation |
Interstellar Matter:
The distribution of the ISM (optical, infrared, radio).
The composition of the ISM (gas, dust).
Manifestations of the ISM (emission/fluorescence, absorption, reflection).
The cause of interstellar reddening (reddening versus Doppler redshift).
Characteristic densities and temperatures of the ISM.
Diffuse cirrus and Giant Molecular Clouds.
Star Formation:
Star forming regions (basic structure, gas and dust, UV radiation, Evaporating Gaseous Globules).
Stars form in groups (hundreds to thousands in a group).
Protostars (protoplanetary disks, jets, Herbig-Haro objects).
Time scales for star formation (pre-Main Sequence evolutionary tracks, depends on mass).
Arrival of protostars on the (Zero-Age) Main Sequence.
Causes for the minimum and maximum stellar masses.
Mass-Luminosity relation on the Main Sequence.
| Lecture XI - | Stellar Evolution |
| | The death of stars |
Brown Dwarfs as failed stars (Jupiter).
Mass and lifetime on the Main Sequence:
Disproportionate relation between mass and luminosity.
Relation between mass and survival on the Main Sequence.
Understanding the concept of evolutionary tracks in the Hertzsprung-Russel diagram.
The importance of open star cluster in understanding stellar evolution:
Main Sequence fitting to determine distances to star clusters.
Main Sequence turn-off point, isochrones.
Determining the age of a star cluster.
Life on the Main Sequence:
Fusion of 4 Hydrogen nuclei into 1 Helium nucleus (only in a star's core).
The proton-proton and CNO cycles.
The stellar thermostat.
Energy production from nuclear fusion and contraction.
Reduction of particles in the core as Hydrogen fusion progresses.
Post-Main Sequence stellar evolution:
Distinguish 4 mass ranges.
Strongly depends on mass.
Massive stars evolve more quickly (turn-off point reveals age of star cluster).
Understand general internal stellar structure (build up of core, fusion in shells).
Internal structure changes to maintain hydrostatic equilibrium (evolution on Red Giant Branch).
Helium flash.
Helium fusion in core, Hydrogen fusion in surrounding shell (life on Horizontal Giant Branch).
Build-up of Carbon core, Helium and Hydrogen fusion in shells, (evolution on Asymptotic Giant Branch).
More massive stars (Red Supergiants) form heavier elements in core (Magnesium, Silicon, Iron).
The death of stars:
Mass loss, Planetary Nebulae.
White Dwarfs (size, mass, tempeature).
Recurrent Nova's in evolved binary stars.
Supernovae type Ia (exploding White Dwarfs) and type II (exploding massive stars).
Origin of chemical elements in the Universe.
Neutron stars (size, mass, magnetic fields).
Pulsars (nature).
Black Holes.
| Lecture XII - | The Milky Way |
Appearance of the Milky Way in the night sky.
History of measuring the size of the Milky Way (Herschel, Kapteyn, role of dust).
General constituents (disk, bulge, halo, spiral arms).
Location, distance and age of open and globular star cluster.
Shape and size of the Milky Way (Shapley).
Location and orbit of the Sun (concept of a Galactic year).
Population I and II stars (age, location, chemical composition, orbits).
Young O and B type stars in Solar neighbourhood (hint for spiral arms).
Radio waves from Hydrogen atoms (21cm spectral line).
The distribution of Hydrogen gas (using the Doppler effect and rotation of the Milky Way).
Rotation curve and Dark Matter.
Formation of spiral arms (differential rotation, density waves, periodic induced star formation).
The center of the Milky Way (stellar orbits reveal a super-massive Black Hole).
Highly energetic processes (radio and X-rays).
The discovery of nebulae (Messier, Earl of Rosse).
The three contributions of Edwin Hubble, discovery of extragalactic universe.
Spiral (late-type) galaxies (relative importance of bulge, arms, bar, dust, star formation).
Elliptical (early-type) galaxies (no gas, no dust, no star formation, old stars).
Irregular galaxies (Magellanic Clouds).
Morphological classification ('tuning fork').
The expanding Universe, cosmological redshift (Hubble's Law).
Distribution of dust and gas in late-type galaxies.
Measuring rotation curves and Dark Matter.
Understanding collisions and merging of galaxies (computer simulations).
Groups and clusters of galaxies.
The morphology-density relation.
| Lecture XIV - | Active galaxies |
| | Cosmology |
Active galaxies:
Jets from nuclei of elliptical galaxies.
UV-bright nuclei.
Extremely hot gas in nuclei (spectral lines).
Clouds of radio emission at the ends of long jets.
X-ray and gamma-ray radiation from nuclei (highly energetic processes).
Motions in jets indicate energetic explosions.
A general class of Active Galactic Nuclei.
Bright Quasars as an extreme form of highly redshifted AGN.
Implication of fast variability.
A unified geometric model of AGN's driven by a supermassive Black Hole.
Cosmic evolution of AGN's.
Cosmology:
A long journey from a geo-centric world view to a relativistic Universe.
Implications from Olber's Paradox.
Consequence of an expanding universe.
The concept of cosmic 'archeology'.
The formation and evolution of galaxies.
The distribution of galaxies in an expanding universe.
The (Perfect) Cosmological Principle.
The Cosmic Microwave Background (temperature and fluctuations).
How the distribution of galaxies emerged from the Big Bang, the role of Dark Matter.
The past and future of cosmic expansion (open or closed universe).
The first 400.000 years after the Big Bang, the origin of the CMB
Dark Energy (cosmological constant) and an accelerated expansion.
The amount of matter and energy in the universe.
'We are a way for the cosmos to know itself.'
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