Unit 06: Investigating the Universe

Star

• A celestial body that orbits a planet and reflects light

• A luminous globe of gas which produces its own heat and light by nuclear reaction made of mostly hydrogen and helium gas.

• A solid mass of rock that forms the surface of a planet

• A large collection of stars, gas, and dust bound together by gravity.

Hertzsprung-Russell diagram

• A diagram that shows the relationship between the brightness, surface temperature, and color of stars.

• A chart that categorizes stars based on their distance from Earth.

• A graph that illustrates the lifecycle stages of a star.

• A plot that compares the mass and age of different celestial bodies.

Black hole

• A region in space where gravity is so strong that even light cannot escape.

• A type of star that is extremely hot and bright.

• A massive object that emits light and heat.

• A celestial body that orbits a planet.

Nebulae

• Clouds of dust and gas; site of star formation; remains of dead or dying stars.

• Solid structures formed by the collision of planets.

• Bright stars that are visible from Earth.

• Black holes that consume everything around them.

Cosmic microwave background

• Electromagnetic radiation that remains from the Big Bang and early stages of the universe.

• A type of radiation emitted by black holes.

• The light emitted by stars in the Milky Way galaxy.

• Radiation produced by the collision of cosmic rays with the Earth's atmosphere.

Luminosity

• Total amount of light (energy) emitted by a star or other celestial body.

• The brightness of a star as seen from Earth.

• The distance a star is from Earth.

• The temperature of a star's surface.

Galaxy

• A system of stars and associated matter held together by gravitational attraction.

• A large body of ice and dust that orbits the sun.

• A cluster of planets revolving around a star.

• A type of celestial event that occurs in space.

Big Bang theory

• A scientific theory about the formation of black holes.

• A scientific theory concerning the early development and shape of the universe from a dense state, which began and is still expanding.

• A theory that explains the extinction of dinosaurs.

• A hypothesis about the future of the universe's expansion.

Magnitude

• The measure of the observed visible brightness of a star.

• The distance between two stars in light years.

• The temperature of a star's surface in Kelvin.

• The size of a star compared to the Sun.

Milky Way galaxy

• A galaxy that contains our Sun and its solar system, including Earth.

• A galaxy located in the Andromeda constellation.

• A galaxy known for its spiral shape and bright center.

• A galaxy that is the closest to Earth.