Circumpolar star declination problem

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SUMMARY

The discussion revolves around calculating the minimum declination for a star to be considered circumpolar from the summit of Damavand Mountain in Iran. The observer's latitude is 35° 57′ N, and the altitude is 5,600 meters. The angle of dip was calculated using the formula A = 57.3 * √(2H/R), resulting in approximately 2 degrees 24 minutes 9.06 seconds. The correct approach to determine the marginal declination involves subtracting this angle from the calculated declination of 54 degrees 3 minutes, leading to a final result of 56 degrees 27 minutes 9.06 seconds.

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trina1990
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hi, heres' problem from an international olympiad

"The Damavand Mountain is located at the North part of Iran, in south coast of
Caspian Sea. Consider an observer standing on the Damavand mountaintop (latitude =
35° 57′ N; longitude = 52° 6' E; altitude 5.6 x 10^3m from the mean sea level) and looking at
the sky over the Caspian Sea. What is the minimum declination for a star, to be seen
marginally circumpolar for this observer. Geodetic radius of the Earth at this latitude
is 6370.8 km. Surface level of the Caspian Sea is approximately equal to the mean sea level."

i tried to walk through this problem this way...
the " angle of dip" or the angle subtended by the altitude to the horizon is
A= 57.3(root over) (2H/R) degree
where H=height of the mountain
R= radius of earth

i calculated A to be 2 degrees 24 minutes 9.06 seconds of arcs...

then i calculated the declination of the circumpolar star at this latitude from this formula,
declination>= ( 90 - latitude), so, dec=54 degrees 3minutes..

now to get the marginal declination for that altitude on the mountain top, should i add the "angle of dip" to this calculated declination? like declination=56 degrees 27 minutes 9.06 seconds...?

i need a verification to my calculation & if ther's any error please suggest me the right way to solve...please help...
 
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No, you subtract. On top of the mountain, you can see farther from Polaris, which means a lower minimum declination.
 
oki. . Got it. . Many many thanks
 

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