If you’re a night owl or an early bird, you can use the waning gibbous moon on the night of September 3, 2015 to find Aldebaran, the constellation Taurus’ brightest star. You can also spot the Pleiades star cluster, although you might need binoculars to see the dipper-shaped Pleiades in the moon’s glare.
From mid-northern latitudes, the threesome – the moon, Aldebaran and the Pleiades – climbs above the eastern horizon at late evening on September 3, or around midnight. To know precisely when Aldebaran and the moon rise into your sky, check out this U.S. Naval Observatory page.
The moon, Aldebaran and the Pleiades go upward and westward throughout the night, and reach their high point in the sky just before the first stirrings of morning twilight.
From mid-northern latitudes, look for the moon, Aldebaran and the Pleiades high in the south to southeast in the dark hour before dawn.
From the northern tropics, look high overhead for this threesome.
From the Southern Hemisphere, look for the moon, Aldebaran and Pleiades in your northern sky.
The lit side of the waning moon always points in the direction that it travels in front the constellations of the Zodiac. At present, the waning moon is moving toward the star Aldebaran as we speak. The sky chart below shows you the moon’s daily change of position in the dark hour before dawn for mid-northern North American latitudes.
If you live along the eastern seaboard in the United States, or in eastern Canada, you can actually watch the moon occult – cover over – Aldebaran on the night of September 4-5. We list a few occultation times for your convenience, below.
New York City, New York (September 4-5):
Occultation starts: 11:56 p.m. EDT on September 4
Occultation ends: 12:40 a.m. EDT on September 5
Boston, Massachusetts (September 4-5)
Occultation starts: 11:57 p.m. EDT on September 4
Occultation ends: 12:42 a.m. EDT on September 5
Toronto, Canada (September 5)
Occultation starts: 12:05 a.m. EDT on September 5
Occultation ends: 12:41 a.m. EDT on September 5
Montreal, Canada (September 5)
Occultation starts: 12:06 a.m. EDT on September 5
Occultation ends: 12:43 a.m. EDT on September 5
Click here for more on the lunar occultation of Aldebaran on the night of September 4-5. At this link, the occultation times are given in Universal Time. You must convert to your local clock time to know when Aldebaran disappears behind the lit side of the moon and then reappears on the moon’s dark side. The conversions:
Eastern Daylight Time (EDT): Universal Time – 4 hours
Atlantic Daylight time (ADT): Universal Time – 3 hours
Newfoundland Daylight Time (NDT): Universal Time – 2.5 hours
Bottom line: If you’re a night owl or early bird, watch the moon pass in front of the constellation Taurus the Bull over the next several days. Today’s sky chart shows the night of September 3-4.