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Need homework help (Astronomy)

  1. Oct 24, 2007 #1
    I cannot figure out the answers for the following problems:

    1) If a star has a parrallax of 0.016 second of arc and an apparent magnitude of 6, how far away is it, and what is its absolute magnitude?

    7) If a star is 10 times the radius of the sun and half as hot, what will its luminosity be?

    13) If the orbital velocity of the eclipsing binary in Figure 8-17 is 153 km/s and the smaller star becomes completely eclipsed in 2.5 hours, what is its diameter?
  2. jcsd
  3. Oct 24, 2007 #2


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