Caption: Sky map for the summer night sky. Click on sky_map_unlabeled_summer.pdf for the pdf file.
Features:
Declination is the vertical angular coordinate.
The full range of right ascension is 0h -- 24h.
The sky map only shows the region ∼ 11.5h -- 24h -- 0.5h.
Right ascension 0h is vernal equinox: the point where the Sun crosses the celestial equator going north on about Mar21 every year.
Vernal equinox also means the event of the Sun crossing the vernal equinox.
Declination is measured north and south from the celestial equator which is zero declination.
North is positive and south is negative.
The sky map only extends to declination ∼ 55°, and so the north celestial pole (NCP) and south celestial pole (SCP) regions are NOT shown.
In the summer, the Sun is on the northern segment of the ecliptic (which is in the daytime sky) and the summer night sky contains the southern segment as seen in the sky map.