The Summer Triangle (all night) After dusk in early July, Vega, Deneb, and Altair are the first stars to appear in the darkening eastern sky. Those three bright, white stars form the Summer Triangle asterism - an annual feature of the summer sky that remains visible until the end of December! The highest and most easterly of the trio is Vega, in Lyra. At magnitude 0.03, Vega is the brightest star in the summer sky, mainly due to its relative proximity. It’s only 25 light-years away from the sun. Magnitude 0.75 Altair, in Aquila, occupies the lower right (southern) corner of the triangle. Altair is 17 light-years from the sun. By contrast, Deneb, which shines somewhat less brightly at magnitude 1.25, is a staggering 2,600 light-years away from us; but it shines so brightly because of its greater intrinsic luminosity. The Milky Way passes between Vega and Altair and through Deneb.