In a Binary Star System,an Unseen Component Is Found to Have

question 393

Multiple Choice

In a binary star system,an unseen component is found to have 8 solar masses.It would be visible if the system were a normal star,so it must be a collapsed object.Theoretical considerations tell us that it must be a:

• A) black hole.
• B) neutron star.
• C) white dwarf.
• D) brown dwarf.

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Definitions:

Truman Doctrine

President Harry S. Truman’s program announced in 1947 of aid to European countries—particularly Greece and Turkey—threatened by communism.

Cold War

A period of geopolitical tension between the Soviet Union and the United States from the late 1940s to 1991, marked by espionage, political rivalry, and the threat of nuclear warfare.

Freedom Train

A seven-car exhibit train that toured the United States from 1947 to 1949 to promote American history and ideals.

Marshall Plan

U.S. program for the reconstruction of post–World War Ⅱ Europe through massive aid to former enemy nations as well as allies; proposed by General George C. Marshall in 1947.