Chapter 20 Vocab Flashcards
Star
Very hot sphere of hydrogen and helium gas that emits light.
Red giant
The star is red because it’s surface is cooler and the core is hot enough to convert helium into carbon and oxygen.
White dwarf
Small and very dense star about the size of earth
Supernova
Giant explosion in which a massive star collapses and throws its outer layers in space
Black hole
The leftover core has a mass that is greater than three solar masses and it will collapse and from a black hole
Lightyear
The distance that light travels in one year about 9.5 trillion km
Galaxy
Collection of gas, dust, and stars, bound togetherness by gravity
Cluster
A group of stars or galaxies bound by gravity
Interstellar star
The gas and dust located between the stars in a galaxy.
Quasar
Very luminous objects that produce energy at high rates and are thought to be the most distant objects in the universe
Universe
The sum of all the space matter and energy that exist and that existed in the past and will exist in the future
Red shift
An apparent shift toward longer wavelengths of light caused when a luminous object moves away from the observer
Blue shift
An apparent shift toward shorter wavelengths when luminous object moves toward the observer
The Big Bang theory
The theory that all matter and energy in the universe was compressed into and extremely small volume that 10 to 20 billion years ago it exploded and began expanding in all directions
Nebula
Cloud of dust hydrogen and helium
