On a good night the Mizar-Alcor double can be seen with the naked eye. Actually the system consists of six stars as each of the three stars is itself a double star. A spectroscope is needed to detect their companions. The group is about 88 light years from us. May This star is one of the few carbon stars visible to the naked eye.
Carbon stars are giant stars larger than the orbits of the inner planets of our solar system.
They are best described as huge hot vacuums. Unstable, they pulsate in size and brightness at irregular intervals, averaging 160 days in this case. At its brightest Y can be seen visually as a dim, very red star, below the handle of the Big Dipper. It's so red because it is so cool. It is thought to be less than half the temperature of our sun.