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Home Q & A Board Science-Related Homework Help Physics
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tqwolfork tqwolfork
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11 years ago
1. the cluster be near enough for us to measure the parallax of its stars  
2. we use ultraviolet and X-ray telescopes  
3. we have a well-calibrated period-luminosity relation for Cepheid variable stars  
4. we have telescopes powerful enough to allow us to identify the spectral types of main-sequence stars of many masses in the cluster  
I have finals no time to do homework.
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liftedlifted
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11 years ago
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