In the northern hemisphere we know that summer is truly upon us when the summer triangle appears overhead. Although not an official constellation, it is one of the easiest patterns to find in the northern summer sky.
The chart shows the view looking high in the south-east from London at 11pm UK time on 27 July, although the view remains essentially unchanged all week, with the triangle climbing higher as the evening goes on.
The brightest of its three stars is Vega, in Lyra, the lyre. It is almost overhead from the UK at this time of year. North-east from Vega is Deneb, the brightest star in Cygnus, the swan. Lower in the south-east is Altair, in Aquila, the eagle.
The summer triangle frames the northern Milky Way. From a dark site, the Milky Way reveals itself as a pale band of light running across the sky. It is the combined light of billions of stars that make up the wider sweeps of our galaxy.
From the southern hemisphere the summer triangle is also visible, but it appears in the northern sky and never climbs that high into the sky. For those in the north, grab a pair of binoculars and enjoy the rich star fields that can be seen within its confines.
