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Circumpolar Stars

  1. Nov 16, 2007 #1
    Help appreciated in advance...

    If one is in the NH, then a circumpolar star must have a declination greater than 90 - observer's latitude.

    But if one is in the SH, what is the corrected formula? do we just convert their latitude to -ve (e.g. 26 South becomes -26) and/or do we change the sign of the equation above....

    if we were asked the question:

    Q) If an observer's latitude is 26 degrees south, find the declination of stars that are circumpolar to this observer.

    How would one solve such a question
  2. jcsd
  3. Nov 16, 2007 #2


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    Declination of the south pole is -90
    so you could either take your southern latitide as -ve and use exactly the same equation

    -90 - -26 = -64 or use positive values and flip the sign at the end, 90 - 26 = 64 => -64
  4. Nov 16, 2007 #3
    so would that mean stars need to have a declination greater than/less than 64 degrees south.

    i.e. would a star be circumpolar if its dec is -63 or -65?
  5. Nov 16, 2007 #4


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    Always confusing to talk about greater/less with negative numbers so lets say nearer -90, ie -65 is circumpolar
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