The Ultimate Guide to Observing the Winter Sky (Northern Hemisphere)

Orion

Orion, the Hunter in Greek mythology, is one of the most recognizable and easiest-to-identify constellations in the Northern Hemisphere's winter sky. In the Southern Hemisphere, it is visible in the summer sky and is seen upside down! If you use your imagination, Orion appears like a "bow tie" in the sky! Three medium bright stars in a row, Alnitak, Alnilam, and Mintaka, comprise Orion's Belt. The four corner stars, the reddish star Betelgeuse top left, Bellatrix top right, Saiph bottom left, and bluish-white Rigel bottom right, make out Orion's body. Some fainter stars create patterns that make Orion appear holding a club and shield as he faces a charging Taurus. You might notice three faint stars that make up his sword region, including a "fuzzy star" in the middle. We will cover that later.

Taurus

Taurus, the Bull, can be seen to the upper right of Orion. This easily recognizable zodiac constellation is famous for its V-shaped horns and appears to be charging at Orion. Taurus is easy to find and can be seen from the city. Its bright reddish-orange star, Aldebaran, forms one of the bull's eyes and helps find the famous Hyades star cluster. Although Aldebaran appears to be part of the cluster, it is not, and it is further away but lies in the same line of sight.

Auriga

The celestial Charioteer Auriga is shaped like a pentagon and can be found above the constellation Taurus. Both Taurus and Auriga share the same star, El-Nath. Auriga can be identified by its brightest star, Capella, a multiple-star system consisting of four stars — two large binary stars and two fainter binary dwarf stars. Auriga is often shown holding a female goat and three baby goats, known as "The Kids," along with the reins of a chariot. Several bright open clusters are visible because part of the winter Milky Way passes through its borders.

Gemini

Gemini, the Twins in Latin, is another zodiac constellation located to the upper left of Orion and between fellow zodiac constellations Taurus and Cancer. The two brightest stars in the constellation are named after Pollux and Castor, two bright stars in Greek mythology. They represent the heads of the twins. Fainter stars outline their bodies down to their feet. Pollux, a golden star, is known to have an extrasolar planet or exoplanet. Scientists estimate it has a mass of at least 2.3 times that of Jupiter! Castor is white with a tinge of blue, but what makes Castor unique is that it is a triple star. Each of its components is a double star, so there are six stars in all!

Canis Major

Canis Major, the Big Dog, and Orion's faithful companion, stands below and to the left of his master, who dominates the winter sky. The three bright stars in Orion's belt point to the brightest star in the night sky, Sirius, also known as the Dog star, which makes up the canine's head. Sirius appears to be a single star but is, in fact, a double star. Its faint companion star, Sirius B, "The Pup," is a white dwarf that orbits the primary star every 50 years, making it a binary star system. Sirius is near Earth, only 8.6 lightyears away from us.

Canis Minor

Unlike its bigger brother, Canis Major, Canis Minor, the Little Dog, is the smaller of Orion's two hunting dogs between Canis Major and Gemini. Its constellation is only composed of two naked-eye stars resembling a straight line. Procyon is the brighter star of the two, known as the "Little Dog Star." This white/yellow star can be located by drawing an imaginary line through the two stars marking Orion's shoulders, Betelgeuse and Bellatrix. And just like Sirius, Procyon is a binary star system with a white dwarf star and is a close neighbor at 11.5 lightyears from us.

Lepus

Lepus, "the Hare" in Latin, lies south of the celestial equator but can be seen in the Northern Hemisphere in winter. It is a small constellation and can be found just below Orion. First identified by the Greek astronomer Ptolemy, Lepus is represented as a rabbit pursued by Orion and his two faithful hunting dogs, Canis Major and Canis Minor. Luckily for the rabbit, Orion encountered Taurus the Bull instead, but the rabbit's "on the run" position is forever etched in the sky.

Winter Hexagon 

One of two major asterisms seen in the winter night sky, the Winter Hexagon is not an official constellation but an outline formed by seven first magnitude or brighter stars in six prominent winter constellations: Sirius in Canis Major, Procyon in Canis Minor, Pollux in Gemini, Castor in Gemini, Capella in Auriga, Aldebaran in Taurus, and Rigel in Orion. Use your imagination and connect with the stars to see this cool wintertime pattern. No binoculars or telescopes are needed.

Winter Triangle

The second of two major asterisms seen in the winter night sky, the Winter Triangle, is not an official constellation. Its outline is formed by three zero magnitude or brighter stars in three prominent winter constellations: Betelgeuse in Orion, Procyon in Canis Minor, and Sirius in Canis Major. Use your imagination and connect the stars to see this cool wintertime triangle of bright stars. No binoculars or telescopes are needed.

The Orion Nebula (Messier 42) 
The Orion Nebula, also known as M42, is one of the most famous and easily visible deep sky objects in the winter sky. M42 is located in Orion's sword region and, with the unaided eye, appears to be a "fuzzy star" shining at magnitude 4. The nebula is transformed into a huge grayish "cosmic flower" of gas and dust through a telescope or a small pair of binoculars. M42 is an interstellar nursery where baby stars are formed. The famous cluster of stars called the Trapezium is in the nebula's core. It illuminates the gases in the Orion Nebula, a diffuse cloud of gas and dust about 1,300 lightyears away.

Pleiades Star Cluster (Messier 45)
The Pleiades, also known as "The Seven Sisters" or M45 is an easily visible wintertime object in Taurus that resembles a "little dipper" with a trail of stars that looks like a tail. Each of the seven sisters has names: Maia, Alcyone, Asterope, Celaeno, Taygete, Electra, and Merope. However, this famous cluster comprises hundreds of super-hot young bluish stars about 410 light years away from Earth. The brightest stars in the formation glow from gas that formed within the last 100 million years. Use Orion's belt as a pointer to the bright star, Aldebaran, and then toward the Pleiades. Use your unaided eyes, small binoculars, or a low-powered telescope for the best views.

Hyades Star Cluster 
The V-shaped figure of stars (except Aldebaran) that forms the bull's head highlights the five brightest stars in the Hyades. In a dark sky, the Hyades stars are visible to the unaided eye but come alive in small binoculars or through a low-power telescope. An easy target for beginners!

Crab Nebula (Messier 1) 
Located in Taurus next to its "Southern Horn" star, Zeta Tauri, the Crab Nebula is the first entry in the Messier catalog. The Crab Nebula is a supernova remnant first observed and documented by Chinese astronomers in 1054 AD. The explosion was so bright that it was visible to the naked eye for up to two years after it went supernova. At magnitude 8.4, it will appear as a hazy cloud in an 8" telescope at 50x from the city. Viewing this nebula in dark skies is highly recommended. There, M1 will be visible in smaller aperture telescopes.

Open Star Clusters (Messier 36, 37, 38)
The constellation Auriga has several beautiful, bright open star clusters that are popular targets for amateur astronomers. M36, also known as the Pinwheel Cluster, is an open star cluster with an apparent magnitude of 6.3 that lies about 4,100 light years from Earth. This cluster contains at least 60 stars and is viewable in binoculars and small aperture telescopes. Binoculars will show a fuzzy patch of light, and small aperture telescopes will reveal just over a dozen brightest stars in the cluster, which appears like a pinwheel. M37 is the brightest and largest of these three open clusters in Auriga. M37 has an apparent magnitude of 6.2 and lies at a distance of 4,511 lightyears from Earth. From the city, binoculars will reveal a fuzzy patch of light, but a small telescope will reveal a tight cluster of stars. An 8-inch telescope will resolve hundreds of stars within the cluster, but the best views will be away from light pollution. M38, known as the Starfish Cluster, has an apparent magnitude of 7.4 and lies at a distance of 4,200 lightyears from Earth. Messier 38 can be seen along with M36 in the same field of view in binoculars as hazy patches. A small to medium-sized telescope will reveal the cluster's "X" shape and many of its stars arranged in pairs.

Open Star Cluster (Messier 35) 
At the foot of Gemini (same side as Castor) resides M35, a beautiful large open star cluster. Believed to be about 175 million years old, M35 is about the size of the full Moon and is barely visible with the naked eye at magnitude 5.1 from a dark sky. M35 is easily visible from the city through binoculars and any size telescope. Just southwest of M35 is a smaller neighboring star cluster, NGC 2158. Use a telescope to spot both clusters side by side.

Sirius
Sirius, also known as Alpha Canis Majoris or the Dog Star, is the brightest star in the night sky, with an apparent magnitude of −1.46, and glows like a white, sparkling diamond. Sirius is 25 times more luminous than our Sun, and its name comes from a Greek word meaning "glowing" or "scorching." Sirius is a binary star. In 2025, its companion, Sirius B "The Pup," a white dwarf star, will reach its largest separation from Sirius "A" in its 50-year orbital cycle. The next few years will be a good time to try to glimpse Sirius B in telescopes as small as 4" (102mm) in aperture. It will be challenging to spot due to Sirius' overwhelming brightness, but the view will be rewarding if you are successful.

Open Star Cluster (Messier 41)
Located about four degrees south of Sirius, M41 is a relatively bright open star cluster of about 100 stars and can be seen with the unaided eye from a dark sky site. From the city, M41 appears as a hazy patch of light in binoculars, with stars resolvable in small telescopes. At the cluster's center resides an orange giant—700 times more luminous than our Sun.

Open Star Clusters (Messier 46, 47)
M46 and M47 are bright open star clusters about a degree apart in Puppis, the Stern. M46 contains around 500 stars and is almost the size of the full Moon, with an apparent magnitude of 6.1. M46 is easy to spot in binoculars and small telescopes. Using Sirius as a guidepost, M46 is located about 14 degrees northeast of the Dog Star, Sirius. In dark skies, a modest aperture telescope will reveal planetary nebula NGC 2438, which appears like a tiny bubble nestled within the cluster's northern boundary. M47 is one of the least densely populated open clusters, with only around 50 stars, taking up about the same size as the full Moon. M47 has an apparent magnitude of 4.2 and is about 12 degrees northeast of the Dog Star, Sirius. Binoculars or a small telescope will easily reveal this loose cluster of stars.

Globular Star Cluster (Messier 79) 
M79 is a rare wintertime globular cluster in Lepus, the Hare, constellation directly south of Orion. The cluster contains about 150,000 stars and has an apparent magnitude of 8.5. It appears as a hazy star in binoculars, while small telescopes will reveal a hazy, brighter core. 8" telescopes will resolve the core into stars.  M79 is an ideal target for urban viewing, and you won't have to wait until summertime to view globular clusters when they are most plentiful.

The winter solstice occurs on Thursday, December 21, at 7:27 p.m. PST in the Northern Hemisphere. It is the shortest day and the longest night of the year. The Sun will appear at its lowest point in the sky as the Northern Hemisphere is tilted farthest away from the Sun. In the Southern Hemisphere, the opposite occurs as the Southern Hemisphere is tilted towards the Sun, and the summer solstice occurs.

Tip #1: Use an Astronomy App or Star Chart

Tip #2: Seeing Conditions

Steady seeing conditions are critical while observing objects such as planets, the Moon, or double stars. However, poor seeing conditions less affect deep-sky objects such as nebulae and galaxies. Avoid nights of bad seeing when our atmosphere is turbulent, and your targets appear like shimmering blobs in your telescope's eyepiece. Start with low magnification and work up if the views remain steady. You will be amazed at how sharp and detailed objects can appear during a night of good seeing.

Tip #3: Telescope Cooldown

Tip #4: Collimation

Collimate, collimate, collimate! If you own a Newtonian or Schmidt-Cassegrain telescope, ensure your telescope's optics are collimated. It can make a difference when it comes to discerning fine detail. If the optics are slightly out of alignment, you may cheat yourself out of seeing the clearest and sharpest details. Make it a habit to check collimation and adjust once your telescope is cooled down. Most refractor telescopes generally do not need to be collimated.

Tip #5: Dress in layers

Wintertime offers us amazing views of intergalactic space with an abundance of cosmic jewels, so the cold temperatures should not deter us from venturing outside to use our binoculars or telescopes. Make sure to dress warmly and in layers if you need to adjust your clothing as temperatures change as the night goes on. If you have a beanie and scarf, wear them to keep your head, ears, and neck warm. Gloves are useful too, but they can make things difficult, such as holding on or changing eyepieces. Wear double socks and insulated boots to keep your feet warm, and if you have hand and foot warmers, they can make a world of difference in keeping you warm.