Active and Normal Galaxies

What is the name of our home galaxy?

• Messier 81

• the Whirlpool Galaxy

• the Milky Way

• the Andromeda Galaxy

In the early 20th Century, "faint fuzzies" displaying a variety of shapes in the sky were simply called ___

• faint fuzzies

• nebulae

• smoky dots

• bulging halos

Which astronomer argued, in 1920, that "the Milky Way was all there is"?

• Harlow Shapley

• Edwin Hubble

• Heber Curtis

• Milton Humason

Which astronomer argued, in 1920, that the Milky Way was just one of many galaxies?

• Harlow Shapley

• Edwin Hubble

• Heber Curtis

• Milton Humason

Shapley erroneously noted that one of the spiral nebulae had been seen to rotate, so it must be ___

• small

• big

• old

• young

Which astronomers "unlocked the mystery" of spiral nebulae in the 1920's?

• Harlow Shapley and Milton Humason

• Heber Curtis and Milton Humason

• Edwin Hubble and Harlow Shapley

• Edwin Hubble and Milton Humason

In the 1920's, what type of pulsating stars were observed in the spiral nebula M31 in Andromeda?

• RR Lyrae stars

• G2V type stars

• pulsars

• Cepheid variables

It was known, for Cepheid variables, that the time it took them to pulse was directly related to their ___

• luminosity

• size

• mass

• distance from Earth

If you can measure the period of Cepheid variables, you can determine how far away they are simply by ___

• calculating their absolute magnitude

• measuring the red shift

• measuring their apparent brightness

• using spectroscopy

In the 1920's it was determined that the "Great Andromeda Nebula" was actually ___

• a spiral nebulae

• a Cepheid variable

• within the Milky Way

• an entirely separate galaxy