Galaxy Classification and Characteristics

The video tutorial explores the vast diversity of galaxies in the universe, focusing on their types, characteristics, and classification. It discusses the Andromeda Galaxy, the nearest to the Milky Way, and the Magellanic Clouds. The history of galaxy cataloging is covered, highlighting the Messier and New General Catalogs. The Hubble classification system is explained, detailing the differences between spiral, elliptical, and irregular galaxies.

What is the estimated number of galaxies in the universe?

• 500 billion

• 10 million

• 100 billion

• 1 trillion

Which galaxy is the closest to the Milky Way?

• Sombrero Galaxy

• Andromeda Galaxy

• Large Magellanic Cloud

• Whirlpool Galaxy

What type of galaxies are the Large and Small Magellanic Clouds considered to be?

• Elliptical

• Spiral

• Barred Spiral

• Irregular

What is a defining feature of spiral galaxies?

• They have a spherical shape.

• They are dominated by old red stars.

• They have arched spiral arms.

• They lack gas and dust.

How are barred spiral galaxies different from regular spiral galaxies?

• They have no arms.

• Their arms originate from a central bar.

• They have no nucleus.

• They are spherical.

What is a characteristic of elliptical galaxies?

• They have a central bar.

• They have very little gas and dust.

• They are dominated by young blue stars.

• They have spiral arms.

How are elliptical galaxies classified?

• By the size of their nucleus.

• By the tightness of their arms.

• By their spherical versus elliptical shape.

• By their color.

What does the Hubble Tuning Fork help classify?

• The shape of galaxies.

• The color of galaxies.

• The distance of galaxies.

• The age of galaxies.

What is the intermediate stage between elliptical and spiral galaxies called?

• Irregular

• Sb

• S0

• E7

In the Hubble classification, what distinguishes a type A spiral galaxy?

• A central bar with no arms.

• A large nucleus and tightly wound arms.

• A small nucleus and loosely wound arms.

• No nucleus and no arms.