What type of star is lyra?

Answer 1

The star RR Lyrae is a special type of star, slightly smaller than the Sun, which pulsates in brightness. There are many stars of this type, and they are useful in astronomy because the period of variation depend on their mass and brightness, so they can be used as a standard candle.

Asronomer look for RR Lyrae-type stars in globular clusters, and when they can find one it tells them the distance to that cluster, even if it's too far away to have its parallax measured.