Galaxy Classification and Characteristics

In 1926, Edwin Hubble developed a classification scheme for galaxies, known as the Hubble Tuning Fork. This scheme categorizes galaxies into three main types: elliptical, spiral, and lenticular, based on their visual appearance. Elliptical galaxies have smooth, featureless light distributions, while spiral galaxies have a flattened disc with a spiral structure and a central bulge. Lenticular galaxies have a central bulge and disc-like structure but lack a spiral structure. The classification can be extended to include irregular galaxies and additional features like bars and rings.

What is the name of the classification scheme created by Edwin Hubble for galaxies?

• Hubble Galaxy Map

• Hubble Elliptical

• Hubble Spiral

• Hubble Tuning Fork

How are elliptical galaxies characterized in Hubble's classification?

• By their smooth, featureless light distribution

• By their irregular shape

• By their spiral arms

• By their bar core

What symbol is used to denote spiral galaxies with a bar core in Hubble's scheme?

• S

• E

• S0

• SB

Which of the following is NOT a characteristic of spiral galaxies as you move from type A to C?

• Central bulge decreases in size

• Spiral arm structure becomes more open

• Amount of dust and young stars increases

• Disc size remains constant

What distinguishes lenticular galaxies from spiral galaxies?

• Higher star formation rate

• Lack of visible spiral structure

• Presence of a bar core

• Irregular shape

Which galaxy type is represented by the symbol S0 in Hubble's classification?

• Irregular

• Elliptical

• Lenticular

• Spiral

What is a key feature of irregular galaxies?

• They have a central bulge

• They lack an obvious regular structure

• They have a smooth light distribution

• They have a regular disk-like structure

Which galaxy is an example of an irregular galaxy?

• Whirlpool Galaxy

• Centaurus A

• NGC 2787

• Large Magellanic Cloud

What additional characteristics have been added to Hubble's classification since its creation?

• Color and temperature

• Bars, rings, and spiral arm characteristics

• Distance from Earth

• Size and mass

Which of the following is NOT a broad class in Hubble's original classification scheme?

• Irregular

• Elliptical

• Spiral

• Lenticular