12. The Milky Way Galaxy

The central region of our Galaxy is not as flat as its main disk of stars. Which of the following has roughly the same shape as our central region of stars?

A peanut

Your weird cousin, who is really into astronomy, decides that the return address he uses on his letters is incomplete! To his city, state, and country, he begins to add: "North America, Earth, Solar System..." If he now wants to include the name of the Galaxy's spiral-structure feature in which the Earth is located, how should his address end?

Orion Spur

. Astronomers today know a lot about the size and shape of the Milky Way Galaxy. Which of the following common objects most resembles the shape of our Galaxy?

a CD or a DVD

Astronomers now know that surrounding the main body of our Galaxy (which our various kinds of telescopes have shown to us) and our fainter halo of stars there is

an invisible halo made of dark matter

Which of the following statements about the nuclear bulge of our Galaxy is FALSE?

it is significantly thicker than the disk of the galaxy

our milky way galaxy is what type of galaxy

spiral

William Herschel thought that the Sun and Earth were roughly at the center of the great grouping of stars we call the milky way. Today we know this is not the case. What was a key reason that Herschel did not realize our true position in the Milky Way?

the dust that extends throughout the disk of the Galaxy only allowed Herschel to see the small part of the Milky Way that surrounds us

Which of the following is NOT part of the growing chain of evidence that makes many astronomers suspect there is a black hole at the very center of the Milky Way Galaxy?

the existence of a strong radio source at the center whose size appears to be no larger than Jupiter's orbit

The very strong source of radio waves at the center of our Galaxy is called

Sagittarius A