Stars, Galaxies, and the Universe

What is a light-year?

• 365 days

• the distance light travels in a year

• the distance from Earth to Andromeda

• the amount of energy the sun produces in a year

What characteristics are used to classify stars?

• distance only

• color and distance

• size, brightness, and temperature

• color, brightness, and distance

What does an H-R diagram tell us about main sequence stars?

• Main sequence stars are hot, but not very bright

• Main sequence stars are cool and bright

• Main sequence stars decrease in brightness as they increase in temperature.

• Main sequence stars increase in brightness as they increase in temperature.

Which of the following is the beginning of a star?

• nebula expands

• helium becomes hydrogen

• nuclear fusion begins

• a protostar cools

Which of the following could become a supernova?

• a high-mass star

• a medium-mass star

• a low-mass star

• a black hole

Which type of electromagnetic radiation can humans see?

• x-rays

• ultraviolet radiation

• infrared radiation

• visible light

Telescopes work by collecting and focusing what to make an image clearer?

• electromagnetic radiation

• sound waves

• radio waves

• mechanical waves

What is an object's apparent change in position when viewed from two different places?

• apparent brightness

• absolute brightness

• weight

• parallax

Which of the following uses powers of tens to write very large or very small numbers in shorter form?

• standard notation

• standard form

• expanded form

• scientific notation

What does a star's color reveal about the star?

• the spectrum

• surface temperature

• composition elements

• distance