STAR Atlas:PRO™ frequently asked questions - FAQs
How do I find the time that Astronomical Twilight occurs?
Astronomical Twilight occurs when the Sun has set 18-Degrees below the west horizon. This is the Time when the Sky is completely dark from the effects of the Sun, and is also the optimal Time to begin astronomical observing.
To find when Dark Skies begin; -
1. Start Star Atlas: Pro
2. Go to [Clocks] on the main menu.
3. The time of Astronomical Twilight and when dark skies begin, is shown on the second last item of this menu.