Tags: Star.
BO Microscopii (BO Mic) is a star in the constellation Microscopium located about 170 light years from the Sun. It has been dubbed Speedy Mic because of the ultra-rapid rotation rate. The projected rotational velocity at the equator of this star is about 135 km/s which with an estimated inclination of 70° to the line of sight from the Earth means it completes a rotation every 0.380 ± 0.004 days.