A - type stars are more rare than K - type stars, G - type stars or F - type stars (which are similar to our sun, Sol). Because of their luminosity, they are the second most common stars in the night sky, after B - type stars. Some of the brightest stars we see are A - type stars, including Sirius A, Vega, Altair or Fomalhaut. As long as speed of light remains a hard barrier for cosmic transportation, many settlers will look at these stars as possible destinations. They have a large Habitable Zone.