Vocabulary

__**Hertzsprung- Russel Diagram:**__ a scatter graph of stars showing the relationship between the stars' absoute magnitudes or luminosities __**Magnitude:**__ greatness of size and amount __**Luminosity:**__ the intrisitic brightness of a celestial object __**Nebula:**__ a cloud of dust and gas in outer space __**Main Sequence:**__ The main sequence is a continuous and distinctive band of stars that appear on plots of stellar color versus brightness. __**Giant:**__ Of very great size or force. __**Super Giant:**__ a very large star that is even brighter than a giant, often despite being relatively cool. __**Supernova:**__ a star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass. __**Dwarfs:**__ cause to seem small or insignificant in comparison. __**Galaxy:**__ a system of million or billion of stars, together with gas or dust, held together by gravitational attraction. __**Fusion:**__ the process or result of joining two or more things together to form a single entity. __**Black Hole:**__ a region of space having a gravitational field so intense that no matter or radiation can escape. __**Neutron Star:**__ a celestial object or very small radius and very high density __**Protostar:**__ A contracting mass of gas that represents an early stage in the formation of a star, before nucleosynthesis has begun. __**Scientific Theory:**__ a theory that explains scientific observations __**Big Bang Theory:**__ a theory that the universe originated sometime between 10 billion and 20 billion years ago. __**Light Years:**__ a unit of astronomical distance equivalent to the distance that light travels in one year __**Light Second: T**__he distance light travels in a vacuum in one second
 * __Main Sequence:__** The main sequence is a continuous and distinctive band of stars that appear on plots of stellar color versus brightness
 * __Luminosity:__** The intrinsic brightness of a celestial object
 * __Hertzsprung Russell Diagram:__** The Hertzsprung–Russell diagram is a scatter graph of stars showing the relationship between the stars' absolute magnitudes or luminosity versus their spectral types or classifications and effective temperatures