Astronomy Basics

Astronomy

Branches of Astronomy

• Astrophysics: study of the physical nature of celestial objects and phenomena
• Planetary Science: study of planets, moons, asteroids, comets, and other objects in our solar system
• Cosmology: study of the origin, evolution, and fate of the universe

Types of Celestial Objects

• Stars: massive, luminous balls of gas that are held together by their own gravity
  • Main Sequence: stage in a star's life where it fuses hydrogen into helium
  • Red Giant: stage in a star's life where it expands to become larger and cooler
  • White Dwarf: stage in a star's life where it has exhausted its fuel and has shrunk to a small size
• Galaxies: massive, gravitationally bound systems consisting of stars, stellar remnants, interstellar gas, dust, and dark matter
  • Spiral: galaxy with a spiral shape, e.g. Milky Way
  • Elliptical: galaxy with an elliptical shape
  • Irregular: galaxy with an irregular shape
• Planets: large, rocky or gaseous objects that orbit around a star
  • Terrestrial: rocky planets, e.g. Earth, Mars
  • Jovian: gas giant planets, e.g. Jupiter, Saturn

Astronomical Phenomena

• Eclipse: phenomenon where one celestial object passes through the shadow of another
  • Solar Eclipse: eclipse where the Moon passes through the Earth's shadow
  • Lunar Eclipse: eclipse where the Earth passes through the Moon's shadow
• Black Holes: regions of spacetime where gravity is so strong that not even light can escape
• Supernovae: extremely powerful explosions that occur when a star runs out of fuel and collapses

Astronomical Tools and Techniques

• Telescopes: instruments used to observe and study celestial objects
  • Refracting Telescopes: use lenses to focus light
  • Reflecting Telescopes: use mirrors to focus light
• Spectroscopy: technique used to analyze the light coming from celestial objects
  • Emission Spectra: spectra showing the light emitted by an object
  • Absorption Spectra: spectra showing the light absorbed by an object

Branches of Astronomy

• Astrophysics is the study of the physical nature of celestial objects and phenomena.
• Planetary Science is the study of planets, moons, asteroids, comets, and other objects in our solar system.
• Cosmology is the study of the origin, evolution, and fate of the universe.

Celestial Objects

• Stars are massive, luminous balls of gas that are held together by their own gravity.
• The main sequence is a stage in a star's life where it fuses hydrogen into helium.
• In the red giant stage, a star expands to become larger and cooler.
• A white dwarf is a stage in a star's life where it has exhausted its fuel and has shrunk to a small size.
• Galaxies are massive, gravitationally bound systems consisting of stars, stellar remnants, interstellar gas, dust, and dark matter.
• Spiral galaxies have a spiral shape, such as the Milky Way.
• Elliptical galaxies have an elliptical shape.
• Irregular galaxies have an irregular shape.
• Planets are large, rocky or gaseous objects that orbit around a star.
• Terrestrial planets are rocky planets, such as Earth and Mars.
• Jovian planets are gas giant planets, such as Jupiter and Saturn.

Astronomical Phenomena

• An eclipse occurs when one celestial object passes through the shadow of another.
• A solar eclipse occurs when the Moon passes through the Earth's shadow.
• A lunar eclipse occurs when the Earth passes through the Moon's shadow.
• Black holes are regions of spacetime where gravity is so strong that not even light can escape.
• Supernovae are extremely powerful explosions that occur when a star runs out of fuel and collapses.

Astronomical Tools and Techniques

• Telescopes are instruments used to observe and study celestial objects.
• Refracting telescopes use lenses to focus light.
• Reflecting telescopes use mirrors to focus light.
• Spectroscopy is a technique used to analyze the light coming from celestial objects.
• Emission spectra show the light emitted by an object.
• Absorption spectra show the light absorbed by an object.

Learn about the branches of astronomy, including astrophysics, planetary science, and cosmology. Explore the different types of celestial objects, such as stars and their life stages.