Most promising sub-Neptune-sized planets for atmospheric characterisation. Point colours illustrate the S/N of a JWST/NIRSPEC observation relative to TRAPPIST-1 b. S/N below 1/100th of TRAPPIST-1 b have been removed to enhance readability of the figure. The planets for which the presence of an atmosphere could be assessed by JWST within ~ 100h are encircled in red, if their atmospheric signals are above JWST’s threshold of ~ 50 ppm. The size of the circle is proportional to the size of the planet.