Science review 8.8 & 6.11

• a main-sequence star in spectral class B
• a supergiant in spectral class K
• a main-sequence star in spectral clas K or M
• a white dwarf in spectral class B

The universe has many different components.   Which list places four components of the universe in the most likely order from smallest to largest?

• Planets, stars, galaxies, nebulae
• Nebulae, stars, planets, galaxies
• Galaxies, stars, planets, nebulae
• Planets, stars, nebulae, galaxies

• Star 1 is cooler and less bright than Star 2.
• Star 1 is hotter and brighter than Star 2.
• Star 1 is cooler and brighter than Star 2.
• Star 1 is hotter and less bright than Star 2. 

Which of these correctly compares the masses of different objects in the universe?

• A moon has less mass than a star and more mass than the planet it orbits. 
• A planet has less mass than a galaxy and more mass than the star it orbits. 
• A galaxy has less mass than a moon and more mass than a planet. 
• A star has less mass than a galaxy and more mass than a planet. 

• Main-sequence stars
• Giants
• White dwarfs
• Supergiants

• Student 1
• Student 2
• Student 3
• Student 4

The Milky Way galaxy is describes as a disk of stars orbiting a central point on the disk.  Which of these best explains why people on Earth cannot see the entire shape of the Milky Way?

• Earth is part of this galaxy.
• Many more starts exist outside the galaxy.
• The stars in the center of the galaxy are extremely small. 
• The center of the galaxy consist of a dense cluster of stars. 

• Barnard's Star is less bright than the sun, has a surface temperature below 3,800 K, and is red.
• Barnard's Star is less bright than the sun, has a surface temperature above 3,800 K, and is red.
• Barnard's Star is less bright than the sun, has a surface temperature above 3,800 K, and is red.
• Bernard's Star is brighter than the sun, has a surface temperature below 5,300 K, and is yellow. 

With the use of the Hubble Space Telescope, scientist recently discovered a giant runaway star.  It is 90 times larger than the sun and is very hot and blue-white in color.  Why does the sun to be brighter than this runaway star when viewed from Earth?

• The sun is a different color than the runaway star.
• The sun is older than the runaway star. 
• The sun is closer to Earth than the runaway star. 
• The sun is made of different elements than the runaway star. 

Why does Earth get more energy from the sun than from all the other stars in the universe combined?

• The sun is much larger than the other stars. 
• The sun is much hotter than the other stars. 
• The sun is much more dense than the other stars. 
• The sun is much closer than the other stars.