September 2017

Star calendar September 2017

1 Sept    The equation of time is zero.

2 Sept    The bright star 3 fist-widths above the moon is magnitude 0.93 Altair.

11 Sept    High in the south before first light, the Pleiades Cluster is 1 fist-width above the moon. Aldebaran is 1½ fist-widths to the left.

12 Sept    At its greatest elongation west, Mercury is 17.9 degrees from the sun and rises 1½ hours before sunrise. Aldebaran is less than ¼ finger-width to the moon’s left before first light. The moon occults Aldebaran shortly after sunrise.

13 Sept    Orion lies to the moon’s lower right this morning. The constellation’s brightest star, magnitude 0.5 Betelgeuse, is 1 fist-width below the moon. The moon is at perigee, 57.99 Earth-radii away.

15 Sept    The Gemini Twins, Pollux and Castor, are 1 fist-width to the moon’s upper left. Pollux is the brighter of the two. Procyon is a little more than 1 fist-width to the moon’s lower right.

17 Sept    Low in the east before first light, the waning crescent moon is 3 finger-widths above Venus. Regulus is just below Venus. Mars and Mercury lie beyond Regulus.

18 Sept    The moon slides past Venus and Regulus and lies between Regulus and Mars.

19 Sept    Magnitude -4.0 Venus is less than ½ finger-width above magnitude 1.4 Regulus.

20 Sept    Venus slides to Regulus’ lower left this morning.

21 Sept    Look low in the west as the sky darkens this evening. Magnitude -1.7 Jupiter is 2 finger-widths to the left of the thin crescent moon.

22 Sept    Jupiter is to the lower right of the moon this evening. Autumn begins in the Northern Hemisphere at 4:02 p.m. EDT as the sun crosses the celestial equator from north to south.

25 Sept    Antares, the heart of the Scorpion, is 4 finger-widths below the moon this evening. Saturn is 1 fist-width to the left.

26 Sept   Saturn is 1 finger-width below the moon this evening.

27 Sept    The moon is at apogee, 63.40 Earth-radii away.

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