Today:
Arcturus now settles lower in the west by dark. The second brightest star seen in the northern latitudes, Arcturus is due west at 8:00, and sets tonight in the northwest shortly after 11 o’clock. Its brightness is a combination of distance – relatively close at 37 light years away – and its size, some 26 times the diameter of our Sun.
Friday:
The brightest star in the Summer Triangle, Vega, appears nearly overhead as the last of the twilight fades near 7:40 PM. Vega’s brilliance is due, in part, to its location just 25 light years away, and because it is the fourth brightest star within 50 light years of here. Later this evening, near 9 o’clock, a second star in the Summer Triangle, Deneb, crosses the very top of the sky, the Zenith.
Saturday:
The Moon rises about a half hour before sunset this evening, one day before it becomes exactly Full, the “Corn Moon” as this year’s September Moon is known. The Harvest Moon occurs closest to the Equinox, which this year is October 6th, though the Full Moon goes by many names in various cultures, including the Mid-Autumn Moon in China, the Barley Moon in the British Isles, and the Nut Moon to the Cherokee. The Full Moon appears opposite from the Sun, as was Saturn will be in two weeks. That’s why you’ll see Saturn just to the Moon’s left as the evening progresses.