High Quality Content by WIKIPEDIA articles! Vega is a nearby star of visual spectral type A0V. While similar in many ways to the star Altair, visual spectral type A7V, Vega's total X-ray luminosity is at least an order of magnitude smaller than the X-ray luminosity for Altair. Vega is the first solitary main-sequence star beyond the Sun known to be an X-ray emitter.Vega is rotating rapidly with a velocity of 274 km/s at the equator. Altair also rotates rapidly, with a velocity at the equator of around 286 km/s. Both Vega and Altair are flattened at the poles due to their high rate of rotation. Vega and Altair have lower temperatures at the equator than the poles.