Re: Astronomical Quiz

From: Jeff Umbarger (
Date: Wed Apr 20 2005 - 01:03:27 EDT

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    No, if I specified a point in the celestial sphere
    (let's say RA 12h and Dec +10.0, then you could only
    stand on 10.0N latitude to have the celestial point go
    overhead. Let me clarify with a "bad" example: If the
    point in the stellar field is where Sirus is (RA:
    6.75hr Dec.:-17.75deg) then you would have to stand on
    17.75 South latitude and wait until 6.75hr RA was
    directly above (zenith). This will happen at slightly
    different times throughout the year - sometimes in
    darkness and sometimes in light. But there is one
    point in the stellar field that is always over it's
    corresponding point on earth (that is, a zenith to) in
    light (that is, with the sun less than 6 degrees below
    the horizon) for that point on earth. Where is the
    point in the sky (not on earth!)?
    - Jeff
    --- Tim Rogers <> wrote:
    > Just for clarification, would this be true for any
    > location on the planet?
    > When you say "when observed from directly below on
    > the earth's surface," do 
    > you mean *just* below the earth's surface
    > (centimeters or inches?)
    > Tim Rogers
    > Sugar Hill, GA  USA
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