The distinct three-star belt and hourglass shape of Orion make it easy to spot in the winter night sky. But what if we told you that these are not complete constellations, but rather, asterisms?

An asterism is a pattern of stars in the night sky. That may sound like a constellation, but there are only 88 star patterns officially known as constellations. They divide up the sky and assist astronomers in locating objects. Conversely, asterisms are familiar shapes that may cross multiple constellations. Cultures throughout history have created these patterns as part of storytelling, honoring ancestors, and timekeeping. Orion’s hourglass is just one example.

Try looking for these asterisms this season and beyond:
• Winter Circle (or Hexagon) – this asterism makes up a large portion of the Winter sky using stars Rigel, Aldebaran, Capella, Pollux, Procyon, and Sirius as its points. Similarly, the Winter Triangle can be found using Procyon, Sirius, and Betelgeuse as points. Orion’s Belt is also considered an asterism.

• Diamond of Virgo – this springtime asterism consists of: Arcturus, in the constellation Boötes; Cor Caroli, in Canes Venatici; Denebola in Leo, and Spica in Virgo. Sparkling at the center of this diamond is the bright cluster Coma Berenices, or Bernice’s Hair – an ancient asterism turned constellation!

• Summer Triangle – as the nights warm up, the Summer Triangle dominates the heavens. Comprising the bright stars Vega in Lyra, Deneb in Cygnus, and Altair in Aquila, this prominent asterism is the inspiration behind the Japanese Tanabata festival.

• Great Square of Pegasus – by Autumn, the Great Square of Pegasus can be seen. This square-shaped asterism takes up a large portion of the sky, and consists of the stars: Scheat, Alpheratz, Markab and Algenib.
Tracing these outlines can guide you to objects like galaxies and star clusters. The Hyades, for example, is an open star cluster in the Taurus constellation, just outside the Winter Circle. It is a favorite of amateur and professional astronomers alike.

How to Spot Asterisms
• Use Star Maps and Star Apps
• Use Constellations to lead you to asterisms
• Use Celestial Landmarks, such as bright stars. Vega in the Lyra constellation is a great example.