Astronomy

A light year is ____

• 365 days

• the distance light travels in a year

• the distance from Earth to Proxima Centauri

• the amount of light the sun produces in a year

Characteristics used to classify stars include

• shape, size, and color

• size, shape, and brightness

• color, brightness, and shape

• size, brightness, and temperature

The Hertzsprung-Russell Diagram shows that main-sequence stars

• are mostly hot and dim

• are mostly cool and bright

• increase in brightness as they increase in temperature

• decrease in brightness as they increase in temperature

A star is born when

• a nebula expands

• helium and oxygen combine

• nuclear fusion starts

• a protostar begins to cool

Eclipsing binary stars can sometimes be identified because

• they are brighter than any single stars

• they are all white dwarfs

• they become dimmer at regular intervals

• they are cool red stars

A supernova is the explosion of a dying

• medium-mass star

• high-mass star

• protostar

• low-mass star

From the cosmic background radiation, scientifsts can infer that, just after the big bang, the universe must have been

• very small

• hot

• the same average termperature it is today

• cooler than it is today

According to Hubble's Law, the farther away a galaxy is,

• the faster it is moving toward us

• the slower it is moving toward us

• the slower it is moving away from us

• the faster it is moving away from us

The electromagnetic spectrum consists of

• all of the colors of ligth you can see with your eyes

• all fo the different types of electromagnetic waves

• a band of colors fromed when white light passes through a prism

• the distance between the crest of one wave and the crest of the next wave

A range of colors formed when white light passes through a prism is called a

• lens

• photograph

• spectrum

• ray