STARS AND GALAXIES IN THE UNIVERSE

What is a galaxy?

• A single large star

• A set of bodies consisting of millions of stars, gas, and dust particles

• A planet with many moons

• A cluster of black holes

Answer explanation

A galaxy is defined as a set of bodies consisting of millions of stars, gas, and dust particles, making this choice the correct answer. The other options describe different astronomical objects.

Which of the following is NOT a form of galaxy?

• Spiral

• Elliptical

• Irregular

• Cylindrical

Answer explanation

Cylindrical is not a recognized form of galaxy. The main types of galaxies are Spiral, Elliptical, and Irregular, each with distinct shapes and characteristics.

The Milky Way is an example of which type of galaxy?

• Elliptical

• Irregular

• Spiral

• Spherical

Answer explanation

The Milky Way is classified as a spiral galaxy due to its distinct spiral arms and flat disk shape, which are characteristic features of this type of galaxy.

Approximately how many stars are in the Milky Way galaxy?

• 2 million

• 20 million

• 2 billion

• 200 billion

Answer explanation

The Milky Way galaxy is estimated to contain around 200 billion stars, making this the correct choice. Other options significantly underestimate the number of stars in our galaxy.

Where is our solar system located in the Milky Way galaxy?

• At the center

• At the edge of one of the spiral arms

• Between two spiral arms

• Outside the main galaxy structure

Answer explanation

Our solar system is located between two spiral arms of the Milky Way galaxy, specifically in the Orion Arm, which is situated between the Perseus and Sagittarius Arms.

Which characteristic is NOT mentioned as a way to classify stars?

• Color

• Size

• Age

• Temperature

Answer explanation

The characteristic 'Age' is not commonly used to classify stars. Instead, stars are typically classified by their color, size, and temperature, making 'Age' the correct answer as it is not mentioned.

What is the relationship between a star's color and its temperature?

• Red stars are hotter than blue stars

• Blue stars are hotter than red stars

• All stars have the same temperature regardless of color

• There is no relationship between color and temperature

Answer explanation

The color of a star is directly related to its temperature. Blue stars are the hottest, while red stars are the coolest. This is due to the fact that hotter stars emit more blue light, while cooler stars emit more red light.

Which color indicates the highest temperature for a star?

• Red

• Orange

• Yellow

• Blue

Answer explanation

The color blue indicates the highest temperature for a star. In the spectrum of star colors, blue stars are the hottest, followed by white, yellow, orange, and red, which are cooler.

What is the correct order of star colors from hottest to coolest?

• Blue, white, yellow, orange, red

• Red, orange, yellow, white, blue

• White, blue, yellow, orange, red

• Yellow, orange, red, white, blue

Answer explanation

Stars are classified by their temperature and color. The correct order from hottest to coolest is blue, white, yellow, orange, and red. Therefore, the correct answer is 'Blue, white, yellow, orange, red'.

The Andromeda galaxy is an example of which type of galaxy?

• Elliptical

•  Irregular

• Spiral

• Lenticular

Answer explanation

The Andromeda galaxy is classified as a spiral galaxy due to its distinct spiral arms and flat disk structure, which is characteristic of this type of galaxy. This makes 'Spiral' the correct answer.