I am designing a bi-newt and I am trying to decide the specification for the instrument. It needs 90 degreees to view the zenith (my eyes horizontal). How low to the horizon is desired? Is anything needed below 10 degrees? I plan to rotate the star diagonal as the scope lowers in order to prevent neck strain.
What declination angle range needed?
Started by BoyntonStu, 03/05/2006 01:15AM
Posted 03/05/2006 01:15AM
Opening Post
Posted 03/05/2006 01:30PM
#1
>>>I am designing a bi-newt and I am trying to decide the specification for the instrument. It needs 90 degreees to view the zenith (my eyes horizontal). How low to the horizon is desired? Is anything needed below 10 degrees? I plan to rotate the star diagonal as the scope lowers in order to prevent neck strain.
====
Stu:
I believe you are interested in the range of "altitudes" required, not the range of "declinations." The declination is the north-south coordinate in the polar coordinate system, the "dec" of Polaris, the North Star, is 89 degrees. The declination of the zenith is equal to your latitude...
Now on to the question... Personally I would want to be able to view the horizon. From my favorite spot, Omega Centauri, the most grand of all globulars at magnitude 3.7 reaches a maximum elevation of 10 degrees. It is a great binocular target, 7.5 times brighter than M13!
I think no matter where you live, there will always be targets near the horizon that are tantalizing....
Jon
====
Stu:
I believe you are interested in the range of "altitudes" required, not the range of "declinations." The declination is the north-south coordinate in the polar coordinate system, the "dec" of Polaris, the North Star, is 89 degrees. The declination of the zenith is equal to your latitude...
Now on to the question... Personally I would want to be able to view the horizon. From my favorite spot, Omega Centauri, the most grand of all globulars at magnitude 3.7 reaches a maximum elevation of 10 degrees. It is a great binocular target, 7.5 times brighter than M13!
I think no matter where you live, there will always be targets near the horizon that are tantalizing....
Jon
Funding Member
