Unit 7 - Components of the Universe

The spectral classes of four stars are shown in comparison with an HR diagram.

Based on the information, which star is most like our Sun?

• Star 1

• Star 2

• Star 3

• Star 4

Which statement best describes a galaxy?

• A cloud of gas that is the birthplace of stars

• A system of billions of stars, gas, and dust held together by gravity

• A ball of plasma that experiences nuclear fusion in its core

• A mass of dust and ice that orbits a star in an elliptical pattern

Most stars in the universe fit into one of the four areas on the HR diagram.

Which area of the diagram represents the white dwarfs?

• Area M

• Area X

• Area P

• Area Z

Tags

NGSS.HS-ESS1-3

In November 2013 an object orbiting the Sun seemed to disappear behind the Sun. When a satellite did not detect the object, astronomers thought that the object had been destroyed when it passed close to the Sun. However, when another satellite detected a small, bright object with a fan-shaped tail, astronomers proposed that the object was not destroyed.

What type of object were astronomers most likely observing?

• A comet

• An asteroid

• A meteor

• A nebula

Tags

NGSS.HS-ESS1-4

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

Tags

NGSS.MS-PS2-4

Barnard's Star is about 5.9 light-years from the Sun. The star has an approximate temperature of 2,800 K.

Based on the diagram, what spectral class does Barnard's Star belong to?

• Spectral class O

• Spectral class B

• Spectral class A

• Spectral class M

The HR diagram shows how the Sun is classified among the stars.

A star that is several thousand times brighter than the Sun with a temp lower than 4,000 K is classified as -

• A main-sequence star in spectral class B

• A supergiant in spectral class K

• A main-sequence star in spectral class K or M

• A white dwarf in spectral class B

Tags

NGSS.HS-ESS1-3

Two stars are identified on the HR diagram below.

Based on this diagram, how do the characteristics of Star 1 and Star 2 compare?

• 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

Tags

NGSS.HS-ESS1-3

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

• Planets, stars, galaxies, nebulae

• Nebulae, stars, planets, galaxies

• Galaxies, nebulae, stars, planets

• Planets, stars, nebulae, galaxies

Tags

NGSS.MS-ESS1-3

The Milky Way galaxy is described 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 a part of this galaxy

• Many more stars exist outside the galaxy

• The stars in the center of the galaxy are extremely small

• The center of the galaxy consists of a dense cluster of stars