Maia (20 Tauri)

Maia Nebula (NGC 1432)

The Maia Nebula, NGC 1432.

Maia (20 Tauri) is the fourth brightest star in the Pleiades after Alcyone, Atlas, and Electra, and the 15th brightest star in the constellation Taurus. It is named after one of the seven mythical daughters of Atlas and Pleione.


Maia is a B star that spins more slowly than any other B star in the Pleiades and, as a result, has an atmosphere in which different kinds of atoms are able to drift down under the pull of gravity, while others are lifted up by radiation. These effects make Maia a mercury-manganese star (see manganese star) – a star in which these two, and certain other, chemical elements are greatly enhanced. Maia has also been at the center of a debate. Fifty years ago, Otto Struve suggested that it was slightly variable, with a period of a few hours, and it subsequently became the prototype of a class of 'Maia variables' that also included Pherkad (Gamma Ursae Minoris). However, the reality of this class was disputed and it is now known that the prototype and some others in the purported class are in fact stable (though others do vary but not for any common reason).


Maia illuminates a nearby reflection nebula known as the Maia Nebula or NGC 1432 (apparent diameter 30'; R.A. 3h 45.8m, Dec. +24° 22').


visual magnitude 3.87
absolute magnitude -1.35
spectral type B8III
surface temperature 12,600 K
luminosity 700 Lsun
distance 360 light-years
position R.A. 03h 45m 49.6s,
Dec. +24° 22' 04"