The Hertzsprung-Russell diagram below shows how the brightness, surface temperature, and color of stars are related.Which of these observations of Barnard’s Star is most likely accurate? *

Captionless Image
A Barnard’s Star is less bright than the sun, has a surface temperature below 3,800 K, and is red.
B Barnard’s Star is less bright than the sun, has a surface temperature above 3,800K, and is red.
C Barnard’s Star is brighter than the sun, has a surface temperature below 5,300 K, and is yellow. D Barnard’s Star is brighter than the sun, has a surface temperature above 5,300 K, and is yellow.
D Barnard’s Star is brighter than the sun, has a surface temperature above 5,300 K, and is yellow.

2. 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? *
1 point
A Earth is a part of this galaxy.
B Many more stars exist outside the galaxy.
C The stars in the center of the galaxy are extremely small.
D The center of the galaxy consists of a dense cluster of stars.
3.The picture shows sand used to make a model of a galaxy. In the model, each grain of sand best represents: *

A a comet
B a black hole
C an asteroid
D a star

4. Which unit of measurement do astronomers use when measuring the distance between two stars found in the Milky Way? *
1 point
A meter
B light-year
C kilometer
D astronomical unit

5.The sun is a mid-sized, main sequence star. What stage is next in the life cycle of the sun? *
1 point
A red giant
B blackhole
C white dwarf
D neutron star

6. Why does Earth get more energy from the sun than from all the other stars in the universe combined? *
1 point
A The sun is much larger than the other stars.
B The sun is much hotter than the other stars.
C The sun is much more dense than the other stars.
D The sun is much closer than the other stars.

7. Astronomers study many different kinds of objects in our Solar System. Which of the following best describes a difference between comets and asteroids? *
1 point
A Comets orbit planets, and most asteroids orbit the Sun.
B Comets are hot balls of gas, and asteroids are made mostly of ice.
C Comets are made mostly of ice, and asteroids are made mostly of rocks.
D Comets orbit the Sun between Mars and Jupiter, and asteroids form patterns in the sky.

8. Why are light-years used to measure distances in space? *
1 point
A The speed of light is slower in space.
B The speed of light is faster than time.
C Distances in space constantly change.
D Distances between stars are very large.

9. 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? *
1 point
A Comet
B An Asteroid
C A meteor
D A nebula

10. Main sequence stars that are much larger and more massive than our Sun will become Super Giants. They will end their life cycle as *
1 point
A supernova
B nebula
C white dwarf
D neutron star or black hole