Stellarium question

[Craig123]

Hi 

Just a quick question about Stellarium.

I keep hoping to image The Elephants trunk but eveytime I get the chance it's always right overhead... Then the camera and filter wheel end up hitting the mount after an hour or two. Looking at Stellarium is it correct that the centre point of the Azimuthal grid is the Zenith. 

TIA

 

[vlaiv]

Yes, it is correct - that is how you define Zenith - highest point in the sky, and in Alt/Az grid - altitude goes from 0 to 90 degrees from horizon to highest point. Azimuth just represents circles perpendicular to that. Same as Equatorial grid - but there top point is where earth spin axis "penetrates" sky dome - so it is "tilted" Alt/Az grid and level of tilt depends on your location on the globe (at north pole both Alt/Az and Eq grids are the same, while on equator they are tilted by 90 degrees to each other).

[Craig123]

1 minute ago, vlaiv said:

Yes, it is correct - that is how you define Zenith - highest point in the sky, and in Alt/Az grid - altitude goes from 0 to 90 degrees from horizon to highest point. Azimuth just represents circles perpendicular to that. Same as Equatorial grid - but there top point is where earth spin axis "penetrates" sky dome - so it is "tilted" Alt/Az grid and level of tilt depends on your location on the globe (at north pole both Alt/Az and Eq grids are the same, while on equator they are tilted by 90 degrees to each other).

Thanks.. that's very helpful to know as before I wasnt using that grid and  guessing how high it would be..and  of course I was usually wrong. Much appreciated.