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Thread: Question about Right Ascension

  1. #1
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    Question about Right Ascension

    so the stars on the Meridian at midnight would have a Right Ascension value of about how many hours away from the Right Ascension of the Sun?

    can someone answer this and then explain?

  2. #2
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    Quote Originally Posted by frbee View Post
    so the stars on the Meridian at midnight would have a Right Ascension value of about how many hours away from the Right Ascension of the Sun?

    can someone answer this and then explain?
    RA is angle measured eastward from vernal equinox in hours 0-24 hrs. The sun's RA can be looked up for today's date (the sun starts with RA = 0 at vernal equinox and increases by 2 hr/month after that) .

    The stars on meridian would be approx. = RA(sun) + 12 hr.

    (because at midnight, the sun is 180 degrees = 12 hr. around from the meridian).

  3. #3
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    then it is 12 hours away?

  4. #4
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    Quote Originally Posted by frbee View Post
    then it is 12 hours away?
    yes, it is 12 hrs. away

  5. #5
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    thanks thoth.

  6. #6
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    Now he can score that 100% on his quiz!

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