Vega has not much of the elements heavier than helium. Vega is a suspected variable star that may vary slightly in magnitude in a periodic manner. It is spinning rapidly with a velocity of 274 km/s at the equator. This is causing the equator to bulge outward because of centrifugal effects, and, as a result, there is a variation of temperature across the star's photosphere that reaches a maximum at the poles. From Earth, Vega is being observed from the direction of one of these poles.