What kind of stars tend to have shorter lifetimes according to their spectral type?

Herbig Ae/Be stars are a specific type of intermediate-mass young stars that are in the pre-main sequence stage of their development. These stars typically have higher masses compared to main-sequence stars like K, G, and M type stars. The lifetime of a star is inversely related to its mass; more massive stars burn through their nuclear fuel at a much faster rate, leading to shorter lifespans.

Herbig Ae/Be stars have notably shorter lifetimes because they can be significantly more massive than their main-sequence counterparts and evolve rapidly through various phases. Their lifetimes can range from a few million to tens of millions of years, which is significantly shorter when compared to lower-mass stars such as K, G, or M stars, which can live for billions of years.

K stars are cooler and less massive than A or B stars and therefore have longer lifetimes. G stars, like our Sun, are mid-range in mass and also have substantial lifetimes. M stars, despite being among the least massive, can live for hundreds of billions of years. Thus, Herbig Ae/Be stars have intrinsically shorter lifetimes due to their greater mass and accelerated rate of fusion compared to the other spectral types listed.