An Power Squadron acquaintance emailed me the following questions. I draw a large blank, which likely indicates a great void in my underdstanding of Celestial Navigation. Any assistance, answers and explaination would be appreciated. It seems to me that data is missing, year, dates, times, but I could certainly be off base there.
1. GHA Nunki = 60, Lo = 15 E, RA Nunki = 250. What is LHA of Aries ?
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If the Right Ascension of Nunki is 250 then its SHA must be 110. (This must be a made up example because its SHA is actually 76.) Since the GHA is 60 subtract 110 to find the GHA of Aries which comes out to be 310. Add your easterly longitude to this to come up with LHA Aries of 325.
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2. You are at Lo 14 W at ZT 1400. The LMT at your Location is ?
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The central meridian for the zone time is 15 W. You are one degree east of that so your LMT is 1404 since it takes four minutes for the sun to travel that one extra degree and to arrive at the central
meridian.
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3. You are at L 23 41.7' S, Lo 107 12.3' E. At this time, the GHA of the moon is 323 28.8' and its declination is 17 38.6' S. What is the approximate direction of the moon from your position?
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You add your east longitude to the moon's GHA to find your LHA. 323 + 107 = 430 -360 = LHA 70. I would guess the ZN is about west since the declination and the latitude are close. H.O. 249 gives the ZN of 261.
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gl
Thanks in advance.
Alan
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