Winter Sky Asterisms

 When you look up into the sky at the stars in the winter (arguably the best season for stargazing) there are a number of recognizable star patterns, which on their own do not make a constellation. These types of star patterns are called asterisms! Asterisms are defined as a prominent group of stars that is smaller than a constellation. They can be used to easily locate other celestial objects in the night sky. Examples of winter asterisms include; the Winter Hexagon and Triangle, Cassiopeia’s W, Orion’s Belt, and the Big Dipper.

The Winter Hexagon is a collection of some 1st magnitude stars, or the brightest stars in the sky, arranged in a noticeable hexagonal pattern. The six stars come from six different constellations; Rigel in Orion the Hunter, Aldebaran in Taurus the Bull, Capella in Auriga the Charioteer, Pollux in Gemini the Twins, Procyon in Canis Minor the Small Dog, and Sirius in Canis Major the Big Dog. Three stars within the Winter Hexagon make up the Winter Triangle, Betelgeuse in Orion, Sirius in Canis Major, and Procyon in Canis Minor. The Winter Hexagon and Triangle are located in the sky to the east, right above the horizon.

Winter Hexagon and Triangle

The Cassiopeia constellation itself has a large number of stars, but 5 of the brightest are arranged in a large “W.” The constellation is seen in the sky year round in our hemisphere, but during the winter months, Cassiopeia’s “W” is located above the North Star, or Polaris, and is upside down. During the summer months, the “W” shape is right-side up. To locate Cassiopeia or the “W” Asterism, search the northeast section of the sky, near the Little Dipper.

Cassiopeia's W

 Orion’s Belt and the Big Dipper are possibly the two most famous winter sky asterisms. Orion’s Belt is a line of 3 stars that makes up Orion’s waistline in The Hunter’s constellation. This asterism is an easy tool to use to locate the Orion Constellation! Look to the southern skies near the horizon for Orion. The Big Dipper is formed from the 7 brightest stars in the Ursa Major, or the Great Bear, Constellation. 6 of these 7 stars are at 2nd magnitude or higher, making it one of the most easily spotted star formations in the sky! Search the northern skies, right above the horizon for the Great Bear.

Orion the Hunter

Ursa Major

If you are looking to go stargazing in the next coming weeks, be sure to keep an eye out for these winter asterisms and their constellations! Beaver Creek Reserve is a great place to look for stars all year round! Listed as an area of Wisconsin’s darkest skies, Beaver Creek partners with the Chippewa Valley Astronomical Society to host a variety of sky gazing programs in our Hobbs Observatory. Hobbs Observatory Astronomical Series are held on the third Saturday of every month and include a 30-45 minute program on various astronomical topics, followed by public observing with the telescopes if conditions are right. Public Observing sessions are held on all clear Saturdays from May through October. These sessions begin 30-45 minutes after the sun sets, and run for about 2 hours. Check out Beaver Creek Reserve to experience some of the best stargazing opportunities in the area!