- BETA DOR (Beta Doradus). Among the most important of all stars are the Cepheid variables, named after the prototype, Delta Cephei. Many of them dot the naked- eye starry sky, their number including Eta Aquilae, Zeta Geminorum (Mekbuda), even Polaris, the brightest of them (though Polaris’s variations are too small to be witnessed by eye). Here is another bright one, fourth magnitude (averaging 3.76) Beta Doradus, the second brightest star (after Alpha) in the modern southern constellation Dorado, the Swordfish.