How to find the Great Square
When to look
September, October, November evenings
Face south-east, then south
Four medium-bright stars in a big, nearly empty square, bigger than your outstretched hand, high in the autumn sky. Autumn evenings, September to November, high in the south-east and then the south. The drawing below is made from the real positions of its 4 stars, as the sky looks when you face it, with bigger dots for brighter stars. No telescope needed.
The Great Square is four stars in a big square. It's high in the sky in the fall. Can you count any stars inside it?
The Great Square marks the body of the constellation Pegasus; one corner star, Alpheratz, belongs to the next-door constellation Andromeda. It's so big and empty that counting the faint stars inside it is a good test of how dark your sky is.
From a town you may see no stars inside the square; from a dark site, a dozen or more. From Alpheratz, a chain of stars leads north-east to the Andromeda Galaxy, a faint smudge to bare eyes that is about 2.5 million light-years away.
The stars in it
Markab, Scheat, Alpheratz, Algenib. The brightest is Alpheratz.
How to find it
- Go out after dark with a grown-up, and give your eyes ten minutes away from screens.
- Face south-east, then south and look for: four medium-bright stars in a big, nearly empty square, bigger than your outstretched hand, high in the autumn sky.
- Hold up this page's drawing or the printed card and match the shape to the sky. If the sky is clear.
More star patterns
“Star patterns turn through the night, so the shape may be tipped on its side. Turn your head, not the sky.”