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Meridian Flip Clock

 
The Meridian Flip Clock is visible in the Main APT screen.
 
Related videos:
 
The Meridian Flip Clock gives an easy way to monitor the important event for most telescope mounts - the passing through the celestial meridian. Usually this affects mount tracking because of the gear engagement change. For other setups it is important to monitor the meridian closing because in some positions the telescope can hit the tripod or pier.
 
In order to show data the Meridian Flip Clock needs a connection to the mount and also the tracking to be engaged. If there is no mount or it is not tracking the clock looks like:
 
 
In some steps during automated meridian flip process the tracking is disabled, but the object position is known so the Meridian Flip Clock will continue to show accurate calculations of the meridian passing moment.
 
If the option "Auto-hide Meridian Flip Clock" in Scope & Focuser settings tab is enabled, the clock be invisible when there is no mount connection.
 
Few theory notes. The celestial meridian is a whole circle, not only the visible part from horizon to horizon. Every object is crossing the meridian two times per 24h - once in the highest position (point A) and once in the lowest position (point B) of it path. For the objects near to the celestial poles is possible both the highest and lowest positions to be above the horizon. Point A defines the transition from the Easter celestial hemisphere to the Western hemisphere. Point B from Western to Eastern.
 
The Meridian Flip Clock shows the time and the minutes to next meridian crossing which can be Point A or B. As soon as object is in Point A it has exactly 720 minutes (12h) to reach Point B. The amount of time is same from Point B to Point A.
 
Both sides of the clock shows E or W. The left side shows in which celestial hemisphere the object is in the moment. The numbers between the two letters show the minutes to next meridian passing the exact time of this moment. The next two pictures show that the scope is pointing to an object in the Easter celestial hemisphere:
 
Shows the exact time of the meridian flip
 
Shows the minutes till the meridian flip
 
In 19:30 the W will be in left E in right showing that scope is pointing in the Western celestial hemisphere, the minutes will be 720 (12h), the time will be 7:30. This shows when next meridian crossing (in Point B) will happen.