Fireworks galaxy, NGC 6946, in the constellations Cepheus and Cygnus. Torrey, 6/4/2016 (revised color)

It is new moon early June and the nights are dark but short. Summer solstice is only two weeks off and it does not get dark enough for observing until 10:40 PM. It will start getting light again in just five and half hours. Dark enough for observing is known as astronomical twilight and technically starts when the sun is 18 degrees below the horizon or almost two hours after sunset. Before astronomical twilight comes nautical twilight, defined by the old mariners as when the horizon at sea is still barely discernible. Continue reading →