The Christmas night sky 2023: The Northern Cross lights the way


The Yuletide evening sky offers a delightful celestial spectacle. As you gaze towards the east, you’ll be captivated by a stunning display of brilliant stars, resembling a celestial Christmas tree. These groupings of stars, known as asterisms, are distinct and can be found within or forming part of recognized constellation outlines. They vary in size, ranging from expansive formations visible to the naked eye to intricate stellar settings that require a telescope. Asterisms can be observed throughout the year, in every quarter of the sky.

Some of the larger asterisms, such as the Big Dipper in Ursa Major and the Great Square of Pegasus, are more well-known than their host constellations. One particularly famous asterism graces the northwest sky on frosty evenings. Originally referred to as the “Bird” in ancient times, this constellation later became known as Cygnus, the Swan. However, its brightest six stars form an asterism called the Northern Cross, which is more popularly recognized. The top of the Cross is adorned by the radiant star, Deneb, while Albereo, situated at the foot, consists of two stars with strikingly contrasting colors: an orange third magnitude star and a fifth magnitude blue companion. Even with a low-power telescope, you can clearly see this beautiful pair.

Although the Northern Cross is typically associated with summertime, it is currently best positioned for viewing, appearing majestically upright on the northwest horizon around 8:30 p.m. local time. Its orientation during this time of year makes it resemble a Christmas symbol. Additionally, just before dawn on Easter morning, the Cross lies horizontally in the eastern sky.

Moving towards the southeast part of the sky, you’ll notice a large package tied with a pretty bow in the same time frame. Four bright stars outline the package, while three stars positioned closely together and in a straight line form the decorative bow. While this may seem like a product of modern imagination, tradition tells us that these seven stars represent Orion, a mighty hunter and one of the most prominent constellations visible from anywhere on Earth. Orion’s figure is connected to great national heroes, warriors, and demigods in various ancient cultures. However, unlike Hercules, Orion is a somewhat enigmatic figure, with numerous mythological stories surrounding him.

The origin of Orion’s name remains uncertain, although some scholars suggest it may have a connection to the Greek word “Arion,” meaning warrior. Regardless, it is universally acknowledged that Orion is depicted in the stars holding his club raised in his right hand. Hanging from his left hand is the skin of a lion he has slain, which he defiantly brandishes in the face of Taurus, the Bull, charging towards him.

Within the faint zodiacal constellation of Cancer, located to the east, lies the star cluster known as Preasepe, resembling a manger. Cancer is relatively devoid of bright stars and is positioned between the Twin Stars of Gemini and the Sickle of Leo. The Aselli, two stars feeding from the manger, bracket Preasepe to the north and south. To the naked eye, the manger appears as a soft, fuzzy patch or dim glow. However, when observed through binoculars or low-power telescopes, it reveals a mesmerizing sight of several dozen stars. In 1610, Galileo described Preasepe as a collection of more than 40 small stars.

While many Christmas cards depict Santa Claus and his reindeer with a full moon illuminating the night sky, this year’s Christmas night sky will not feature an official full moon. The moon will reach its full phase at 7:33 p.m. Eastern Time on the night after Christmas, known as the Full Cold Moon. On Christmas night, the moon will still be in the waxing gibbous phase, appearing 99% illuminated. Even on Christmas Eve, it will shine at 96% of full. Although some may mistake a moon that is 90% illuminated for a full moon, the next time a full moon coincides with Christmas Night will not occur until 2034.

If you wake up an hour or so before sunrise, cast your gaze towards the east-southeast, and you’ll be greeted by a celestial gem known as “The Shepherd’s Star” — the planet Venus. Flammarion described Venus as a brilliantly shining star in the morning sky, surpassing the luminosity of all other stars. Its resplendence evokes the image of the biblical “Star in the East.”

For those fortunate enough to receive a telescope as a holiday gift, Venus might appear underwhelming as it will display a less appealing gibbous phase. However, two other magnificent planetary targets await your observation. Jupiter, the bright “star” visible in the evening sky, can be found about halfway up from the east-northeast horizon after sundown. Through a telescope, you’ll witness its captivating cloud bands and the presence of its four largest moons. Additionally, “the lord of the rings,” Saturn, can be spotted in the south-southwest sky during the evening. With a telescope magnifying at least 30 power, you’ll be treated to a breathtaking view of Saturn’s iconic rings, currently tilted approximately 9 degrees to our line of sight.

So, as you venture out to stargaze during this festive season, take delight in the celestial wonders that adorn our Yuletide evening sky. From the enchanting asterisms and the awe-inspiring Northern Cross to the mythical figure of Orion and the starry manger of Preasepe, the heavens offer a captivating spectacle to behold. And if you rise early on Christmas morning, let Venus, “The Shepherd’s Star,” remind you of the biblical tale of the Star in the East. With a telescope, explore the majestic Jupiter and the magnificent Saturn, unveiling their hidden splendors. May these celestial wonders bring joy and wonder to your holiday season.



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