Harlow Shapley made the first accurate determination of the position of the center of the galaxy by studying ____.
a. globular clusters
b. open clusters
c. emission nebulae
d. spiral tracers
e. stellar associations
Question 2The ____ of an object is a measure of the amount of matter it contains. The ____ is a measure of the gravitational force on an object.
a. weight; mass
b. mass; weight
c. energy; force
d. force; energy
e. momentum; energy
Question 3What property of a Cepheid variable can you determine if you know its period?
a. surface temperature
b. absolute magnitude
c. apparent magnitude
d. mass
e. radius
Question 4When two objects of unequal mass orbit each other, the center of mass is ____.
a. at the center of the more massive object
b. at the center of the least massive object
c. half way between the centers of each object
d. always closer to the less massive of the two objects
e. always closer to the more massive of the two objects
Question 5William and Caroline Herschel's map included four of the following hypotheses in their model of the galaxy. Which one was the exception?
a. They thought that the holes in the sky were caused by interstellar dust clouds.
b. They proposed that the galaxy had a disk shape.
c. They provided accurate measurements of the distances to stars.
d. They placed the Sun in the center of the galaxy.
e. They found errors caused by a lack of knowledge of the interstellar medium.