Life Cycle of a Star and HR Diagram

The spectral class of four stars are shown in comparison with a Hertzsprung-Russell diagram. Based on the information, which star is most like the 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 experience nuclear fusion in its core.

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

Which statement about stars is correct?

• Star formation begins in a nebula.

• White dwarfs become main-sequence stars when they gain mass.

• Supergiants are stars that can absorb black holes.

• Main-sequence stars are formed by comets.

Tags

NGSS.HS-ESS1-3

Most stars in the universe fit into one of the four areas on this Hertzsprung-Russell diagram. Which area of the diagram represents the white dwarfs?

• Area M

• Area X

• Area P

• Area Z

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

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 Hertzsprung-Russell diagram shows how the sun is classified among the stars. A star that is several thousand times brighter than the sun with a temperature lower than 4,000 K would be 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

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

Two stars are identified on the Hertzsprung-Russell 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.

A Hertzsprung-Russell diagram is shown below. Based on this diagram, which type of stars would belong to spectral class M and have the highest luminosity?

• Main-sequence stars

• Giants

• White dwarfs

• Supergiants