Altair (α Aquilae, α Aql) is the brightest star in the constellation Aquila and the twelfth brightest star in the night sky. It is currently in the G-cloud—a nearby accumulation of gas and dust known as an interstellar cloud. Altair is an A-type main sequence star with an apparent visual magnitude of 0.77 and is one of the vertices of the Summer Triangle (the other two vertices are marked by Deneb and Vega). It is 16.7 light-years (5.13 parsecs) from Earth and is one of the closest stars visible to the naked eye.