Characteristics of the Sun
True or false, the sun is the brightest of all the stars
False
What is a light year?
The distance light travels in one year
Galaxies are classified by their _____
Shape
A chart that graphs a star's brightness and temperature
Hertzsprung Russell Diagram
A huge cloud of dust and gas held together by gravity
Nebula
The sun is made mostly of _____ and ______
Hydrogen and Helium
distance; time
The most abundant type of galaxy that has a smooth, circular/oval shape
Elliptical
In the Hertzrpung diagram, the brightness increases as you move ______.
toward the top of the graph
A star giving off light and heat for the first time; nuclear fusion begins.
Protostar
What category is the Sun, as indicated in the HR diagram?
Main Sequence
The closest star to Earth (besides the Sun) is _______
Alpha Centauri
A random, scattered type of galaxy that does not form a distinct shape or pattern
Irregular
Name the four categories of stars.
main sequence, supergiant, giant, white dwarf
An explosion of a massive star
Supernova
True or False, the Sun is the closest star to the Earth
True
Light travels approximately ____trillion km in one year.
9.5
Which Galaxy has a bulge in the center?
Spiral galaxy
Electromagenetic spectrum allows scientist to determine the _____of movement of objects in the universe.
direction
90% of stars are in this stage of their life cycle
main sequence
The process that fuels the Sun and allows it to give off energy is called?
Nuclear fusion
Why do astronomers use light years to measure distance in space?
distance in space are so large
A galaxy is a huge system of millions or billions of stars, together with gas and dust held together by?
gravity
ten to the power of ____ indicates visible light waves.
-5
The ___ of a star determines its life cycle
mass