How Did Harlow Shapley Use the Period-Luminosity Relationship of Cepheid

question 42

Multiple Choice

How did Harlow Shapley use the period-luminosity relationship of Cepheid variables to determine the size of the Milky Way galaxy?

• A) He determined the proper motion of globular clusters in the outer disk of the galaxy.
• B) He found the distance to individual Cepheid variables free floating in the halo.
• C) He found the distance to open clusters found throughout the disk of the galaxy.
• D) He found the distance to globular clusters distributed about the center of the galaxy.

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Definitions:

Alkoxymercuration

A chemical reaction that introduces an alkoxy group into an alkene to form an ether, typically involving mercury (II) acetate.

Demercuration

A chemical reaction process that removes mercury from an organomercury compound, often used in the context of reductive reactions and organic synthesis cleanup.

Synthesize

The act of chemically uniting simple elements to produce a substance that is more complex.

Ether

A class of organic compounds characterized by an oxygen atom connected to two alkyl or aryl groups, typically used as solvents or in the synthesis of other chemicals.