A circumpolar star or constellation is one that never sets as seen from a given location, but always stays above the observer’s horizon, and can be viewed all year round. Which ones are circumpolar depend on where you are on the planet. For example, from mid-northern latitudes, the stars shown on this chart are circumpolar and are always on view, although the further south you travel, the fewer circumpolar stars there will be (see Circumpolar Stars).
As we have seen, this area of sky is visible from mid-northern latitudes throughout the year and includes the constellations that surround Ursa Minor (the Little Bear) and its prominent leading star Polaris, also known as the Pole Star, and which lies due north.
Generally speaking the Plough, together with the rest of Ursa Major (the Great Bear), can be seen around the zenith or overhead point during mid-evenings in spring, whilst summer evenings see Draco (the Dragon) in this position. Cassiopeia takes their place during the autumn months and the faint and somewhat sprawling Camelopardalis (the Giraffe) in winter.
To start your search of the north circumpolar sky, first of all print out this chart and, facing north, hold it above your head. Now, using the Plough as a guide, rotate the chart and align the pattern of stars shown so they match up with their locations in the sky. Once you’ve done this, the chart will enable you to identify the stars and constellations you can actually see. Once you’ve identified the main constellations shown here, the rest of the (fainter) stars on this chart can be picked out (providing the sky is reasonably dark and clear).
By far the most prominent and well-known group in this region is the Plough, a conspicuous pattern of stars formed from the seven brightest members of Ursa Major. The Plough acts as a useful direction finder to many other stars and constellations. One of these is Polaris. If you extend the line from Merak, through Dubhe in the Plough as shown here this will lead you to Polaris, from which the rest of the stars in Ursa Minor can be picked out.
Now continue the line from Merak and Dubhe roughly as far again past Polaris and this will bring you to Cassiopeia, a distinct W-shaped group of five bright stars. According to legend, Cassiopeia was the mother of Princess Andromeda and wife of King Cepheus of Ethiopia, Cepheus being depicted here as one of the constellations adjoining Cassiopeia. Andromeda lies a little further away from Polaris than Cassiopeia and is best seen in during the autumn.
Other groups in this area of sky include Draco (the Dragon) which winds its way around Ursa Minor, and the two obscure constellations Camelopardalis (the Giraffe) and Lynx (the Lynx). Very clear skies are needed in order to pick out these latter two groups. Neither Camelopardalis or Lynx contain any particularly bright stars and you may need the help of a pair of binoculars to help you identify them.