Fields in Astronomy
Observational Astronomy is the area of Astronomy that deals with direct observations of the universe.
Theoretical Astronomy is Astronomy's theoretical branch
Planetary Astronomy is the field of Astronomy that studies planets
Solar astronomy is the field of Astronomy that studies the Sun.
Stellar astronomy is the field of Astronomy that studies stars.
Galactic Astronomy is the field of Astronomy that studies galaxy the Milky Way
Extragalactic Astronomy is the field of Astronomy that studies galaxies outside the Milky Way.
Cosmology studies the Universe, its structure, composition, history and origin. The influenced by philosophical assumptions on Cosmology results in different cosmologies be produced by different starting assumptions. The Big Bang assumes an unbounded universe, however this resulted in the biggest failure of the Big Bang. This is failure results from the fact that the results of measurements of Type Ia Supernovae produced the one type of result that the Big Bang predicted would not happen. Rather than doing real science an questioning the Big Bang, Dark Energy was invented for the sole purpose of saving the Big Bang from reality.