Study Notes for Chapter 30:

Study Notes forStudy Notes forChapter 30:Chapter 30:

Stars, Galaxies, and the Stars, Galaxies, and the UniverseUniverse

Chapter 30 Section Chapter 30 Section 1:1:

Characteristics of StarsCharacteristics of Stars

11 By analyzing the light that a star By analyzing the light that a star

emits, astronomers can determine emits, astronomers can determine the __________ and __________ of a the __________ and __________ of a star.star.

compositiontemperature

22 Scientists determine the Scientists determine the

composition and temperature of composition and temperature of stars by analyzing the ______ of the stars by analyzing the ______ of the light that stars emit.light that stars emit.

spectra

33 The _______ stars are ____ in color, The _______ stars are ____ in color,

the hottest stars are _____.the hottest stars are _____.coolest red

blue

44 Stars _______ to move in the sky Stars _______ to move in the sky

because ______ is moving.because ______ is moving.appear

Earth

55 A star moving away from the Earth A star moving away from the Earth

has a spectrum that is shifted has a spectrum that is shifted toward ______.toward ______.

red

66 A light-year is the distance _____ A light-year is the distance _____

travels in a year. travels in a year. light

77 About ______ stars are visible from About ______ stars are visible from

Earth without a telescope.Earth without a telescope.6,000

88 ________ magnitude is the ________ magnitude is the

brightness of a star as it appears brightness of a star as it appears from Earth.from Earth.

Apparent

99 ________ magnitude is the true ________ magnitude is the true

brightness of a star.brightness of a star.Absolute

Chapter 30 Section Chapter 30 Section 2:2:

Stellar EvolutionStellar Evolution

1010 After its temperature rises to After its temperature rises to

10,000,000°C, a _________ becomes 10,000,000°C, a _________ becomes a star when nuclear fusion begins.a star when nuclear fusion begins.protostar

1111 During the main sequence stage, During the main sequence stage,

________ fuses into _______ to ________ fuses into _______ to generate energy in a star’s core.generate energy in a star’s core.

hydrogenhelium

1212 A star with the sun’s mass would A star with the sun’s mass would

stay on the _____ sequence of the stay on the _____ sequence of the H-R diagram for about 10 billion H-R diagram for about 10 billion years.years.

main

1313 A large, bright star whose hot core A large, bright star whose hot core

has used most of its hydrogen is a has used most of its hydrogen is a _____._____.

giant

1414 A small, hot, extremely dense core A small, hot, extremely dense core

left after a star collapses is a _____ left after a star collapses is a _____ dwarf.dwarf.

white

1515 A white ______ is a hot, extremely A white ______ is a hot, extremely

dense core of matter left after a dense core of matter left after a star _________.star _________.

dwarfcollapses

1616 Many astronomers believe that Many astronomers believe that

black _______ do not exist.black _______ do not exist.dwarfs

Chapter 30 Section Chapter 30 Section 3:3:

Star GroupsStar Groups

1717 A galaxy is made of stars, dust, and A galaxy is made of stars, dust, and

gas bound together by _______.gas bound together by _______.gravity

Chapter 30 Section Chapter 30 Section 4:4:

The Big Bang TheoryThe Big Bang Theory

1818 Hubble’s discovery that there was Hubble’s discovery that there was

____ shift in the spectra of galaxies ____ shift in the spectra of galaxies lead to an understanding that the lead to an understanding that the universe is _________.universe is _________.

red

expanding

1919 Red shift in the spectra of galaxies Red shift in the spectra of galaxies

told ________ that the universe is told ________ that the universe is expanding.expanding.Hubble

2020 The ____ bang occurred about ___ The ____ bang occurred about ___

billion years ago.billion years ago.big 14

2121 Astronomers believe that cosmic Astronomers believe that cosmic

background ________ formed shortly background ________ formed shortly after the big bang.after the big bang.radiation

2222 Most of the universe is made of Most of the universe is made of

_____ energy and dark _______._____ energy and dark _______.dark

matter

THE ENDTHE END