it is the twelfth brightest star in the night sky. it is in the g-cloud—a fog 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. it is one of the vertices of the summer triangle (the other two vertices are deneb and vega). it is 16.7 light-years (5.13 parsecs) from the sun and is one of the closest stars visible to the naked eye.