a rightly timed pause

Plants use chlorophyll instead of some other pigment to drive photosynthesis because it is more efficient to absorb red and blue photons, based on the output of our sun and the light filtering attributes of our atmosphere. When they took these variables into account, the researchers found that planets around Class F and Class K stars, which are somewhat similar to our sun (Class G), would tend to have plants with either blue or red pigment, depending on the intensity of the starlight. Class M stars, aka red dwarfs, are cool stars that don’t give off any ultraviolet radiation late in their lives. The relatively small amount of light available could result in black plants that try to absorb all the photons they can.