Comparison between the Sun and the ultracool dwarf star TRAPPIST-1
This picture shows the Sun and the ultracool dwarf star TRAPPIST-1 to scale. The faint star has only 11% of the diameter of the sun and is much redder in colour.
As the planets found around TRAPPIST-1 orbit much closer to their star than Mercury is to the Sun, they are exposed to similar levels of radiation as Venus, Earth and Mars in the Solar System.
Last Update: 1 September 2019