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Author Question: Using the technique of main-sequence fitting to determine the distance to a star cluster requires ... (Read 30 times)

Capo

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on: Jul 27, 2018
Using the technique of main-sequence fitting to determine the distance to a star cluster requires that ________.
 
  A) we use ultraviolet and X-ray telescopes
  B) we have telescopes powerful enough to allow us to identify the spectral types of main-sequence stars of many masses in the cluster
  C) the cluster be near enough for us to measure the parallax of its stars
  D) we have a well-calibrated period-luminosity relation for Cepheid variable stars

Question 2

The COBE data allow us to test the isotropy of the universe.
 
  Indicate whether the statement is true or false


yuyiding

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Reply #1 on: Jul 27, 2018
Answer to Question 1

B

Answer to Question 2

TRUE


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