A Class A star is the third brightest type of main sequence star. They are typically coloured white. They make up roughly 0.7% of main sequence stars.

A typical Class A star has a mass of 2 (1.6 to 2.9) solar masses, a radius of 1.7 (1.5 to 2.4) solar radii, a luminosity of 20 (6.5 to 54) solar luminosities, a surface temperature of 8500 K (7200 K to 9500 K), and a lifespan of 1 billion years.

They are hot, bright, and short lived, which means that significant complex life in unlikely to develop around them. However, some simply life may have time to form in the habitable zone approximately 5 AU away from the parent star.

Stellar Classes
Y · T · L · M · K · G · F · A · B · O · W · D · Neutron star · Black hole