Chap. 13 Astrophysics Flashcards
Define stellar clustes and constellations
STELLAR CLUSTER: A group of stars which are close to each other due to the collapse of a gas cloud. They are gravitationally bound, and exist in the same region of space.
CONSTELLATION: A pattern of stars in the sky as viewed from Earth. They are probably not near each other nor gravitationally bound.
What is the **Asteroid Belt **
The Asteroids Belt is billions of rocky objects which orbit the Sun between the inner and outer planets.
What are comets
Comets are made of ice and rock and orbit the Sun with highly eccentric orbits.
What is a galaxy
A group of stars held together by gravity. Typically contains 1011 stars and is 105 ly across. Distances between stars approx. 1 ly. Distance between galaxies 106 ly. Shapes can be spiral, globular or irregular.
