With summer’s luminaries dropping from view, a new season opens up in the evening sky. Pegasus slides into view in the east shortly after night falls, marked by the Great Square. The constellations that form the “celestial sea” — Capricornus, Aquarius, Pisces, and others with a watery theme — flow across the south during the night. The Milky Way arches high overhead during the evening, putting on a grand display from sites with dark skies.
This Week's Stargazing Tips
September 2: First-Quarter Moon
The Moon is at first quarter early today. Sunlight illuminates exactly one-half of the lunar hemisphere that faces Earth. The sunlit portion of the Moon will continue to grow until the Moon is full on September 8, the night of the Harvest Moon.
September 3: Gamma Cephei
Gamma Cephei forms the “top” of the northern constellation Cepheus, the king. The constellation looks like a child’s drawing of a house, with Gamma Cephei at the top of the roof. The system consists of two stars and at least one planet.
September 4: Zenith
Vega, one of the brightest stars in the night sky, passes high overhead this evening. From the middle latitudes of the United States, in fact, it passes directly overhead, the point in the sky called the zenith.
September 5: Dabih
The gibbous Moon will hide one of the brightest stars of Capricornus tonight. Dabih stands close to the left of the Moon as night falls. The Moon will then slide closer to the star, eventually passing directly in front of it and blocking it from view.
September 6: Ophiuchus
The 13th constellation of the zodiac rolls across the sky this evening. Ophiuchus is in the southwest at nightfall and begins to set after midnight. It covers such a huge area that it takes several hours for the whole thing to drop below the horizon.
September 7: Rasalhague
The brightest star of Ophiuchus, the serpent bearer, is Rasalhague, from an Arabic name that means “head of the serpent bearer.” To see it, first find bright orange Antares, which is much lower in that direction. Look directly above Antares until you come to the first moderately bright star.
September 8: Harvest Moon
The Moon is full at 8:38 p.m. CDT tonight. As the full Moon closest to the autumnal equinox, it is known as the Harvest Moon. In ages past, the Harvest Moon’s light gave farmers extra time to harvest their crops.
Check last week's tips if you missed a day.