{{ t.label }}
Hours above altitude threshold
Latitude {{ latLabel }}
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Usable dark hours by RA / Dec
{{ darkInfo }}
Clear points
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Planets at local midnight
Planet
RA
Dec
Usable
{{ p.name }}
{{ p.raLabel }}
{{ p.decLabel }}
{{ p.hoursLabel }}
cos H = (sin alt − sin φ sin δ) / (cos φ cos δ) · usable = overlap of [RA − H, RA + H] with the astronomical dark window (Sun below −18°), in local sidereal time