Observable Objects in Our Universe
Planetary System, with our solar system as an example, and many new exosolar systems are discovered
Galaxy
Compact Objects
The Universe
History
Components: The Universe is mainly composed of dark matter, dark energy and only a few atomic matters.
Black holes
Quasars
Morphology of our Milky Way is like a bar surrounded with several spiral arms.
Morphology and age: Hubble Tuning Fork shows that the more irregular the shape of a galaxy is, the younger it is.
Planet
Star
Detection Methods, including transit, radial velocity, micorlensing, photometry, direct imaging...
Components: The components of planets vary as their radius gets larger.
The Sun is mainly formed by hydrogen, helium, and a small quantity of metal.
Life cycle of stars is determined by their mass. High mass stars will become black holes or neutron stars, while low mass ones will become black dwarfs.
HR diagram, a traditional diagram by which we understand and classify stars, with temperature as x-axis and brightness as y-axis
Spectral types: Stars are divided into seven classes, O, B, A, F, G, K, M, according to their surface temperature.
Major Studies into Different Objects
An exercise to judge which star cluster is older.
The spectral lines of planetary and star formation nebula differ.
Pulsars
Neutron stars
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