ALTAIR - is the brightest star in the constellation Aquila and the twelfth brightest star in the nighttime sky, at visual magnitude 0.77.Altair is a vertex of the Summer Triangle. It is a white star located 17 light years away from Earth (about 100 trillion miles), one of the closest stars visible to the naked eye. Altair is most notable for its extremely rapid rotation, by measuring the width of its spectral lines, it was determined that its equator does a complete rotation in about 6½ hours. For comparison, our Sun requires just over 25 days for a complete rotation. As a result of its rapid rotation, Altair is oblate, its equatorial diameter is at least 22 percent greater than its polar diameter. Altair, along with Beta Aquilae and Gamma Aquilae, form the well-known line of stars sometimes referred to as the shaft of Aquila.
