In the Sky This Month

The Horsehead Nebula, in the constellation Orion, is visible through telescopes. It consists of a bright pink cloud of hydrogen gas with a dark cloud of cold dust in front of it. Part of the dust cloud forms the outline of a horse’s head.

The star Spica poses near the Moon at first light tomorrow. They climb into good view by 2 or 3 a.m., with Spica to the lower right of the Moon. Spica is the brightest star of the constellation Virgo and one of the 20 brightest stars in the entire night sky.

Phoenix, the mythical bird that represents rebirth, stands just above the southeastern horizon at sunset and drops from view by midnight for skywatchers in the southern United States. The constellation’s brightest star, Ankaa, is at its northern tip.

Three steeds gallop across the sky tonight: Pegasus, the flying horse; Equuleus, the little horse; and Monoceros, the unicorn. Pegasus is the brightest. Look for its Great Square high in the sky: four fairly bright stars that outline the horse’s body

Sirius is the leading light of Canis Major, the big dog, so it is known as the Dog Star. It is the brightest star in the night sky. Sirius is much brighter than the Sun, and it’s also a close neighbor at a distance of less than nine light-years.

The gibbous Moon climbs into good view late this evening. The bright star Regulus, the heart of Leo, the lion, follows it across the sky.

The star cluster Messier 34 sits on the border between the constellations Perseus and Andromeda. It is high overhead during the evening, between two bright stars. Under a clear, dark sky, M34 is just visible to the unaided eye as a fuzzy patch of light.

Orion, the hunter, stands well up in the east and southeast by about 8 p.m. Its most prominent feature is a row of three stars known as Orion’s Belt. Early Christians associated those stars with the Three Magi, the wise men who brought gifts to baby Jesus.

The Moon is full today at 11:49 a.m. CST. As the full Moon closest to the winter solstice, which was yesterday, it is the Long-Night Moon. It will be visible longer than any other full Moon of the year.

Today is the winter solstice. It is the shortest day of the year in the northern hemisphere. The Sun rises late, sets early, and scoots low across the sky during the day. The Moon is full, so it is in view longer than any other full Moon of the year.