The two brightest stars, Alpha and Beta Aquarii, are luminous yellow supergiants, of spectral types G0Ib and G2Ib respectively, that were once hot blue-white B-class main sequence stars 5 to 9 times as massive as the Sun. The two are also moving through space perpendicular to the plane of the Milky Way. Just shading Alpha, Beta Aquarii is the brightest star in Aquarius with an apparent magnitude of 2.91. It also has the proper name of Sadalsuud. Having cooled and swollen to around 50 times the Sun's diameter, it is around 2200 times as luminous as the Sun. It is around 6.4 times as massive as the Sun and around 56 million years old. Sadalsuud is 540 ± 20 light-years from Earth. Alpha Aquarii, also known as Sadalmelik, has an apparent magnitude of 2.94. It is 520 ± 20 light-years distant from Earth, and is around 6.5 times as massive as the Sun and 3000 times as luminous. It is 53 million years old.