↑ The surface gravity is calculated directly from Newton's law of universal gravitation, which gives the formula g = G M r 2 {\displaystyle \scriptstyle g={\frac {GM}{r^{2}}}} where M is the mass of the object, r is its radius, and G is the gravitational constant.
↑ Taking the absolute visual magnitude of TRAPPIST-1 M V ∗ = 18.4 {\displaystyle \scriptstyle M_{V_{\ast }}=18.4} and the absolute visual magnitude of the Sun M V ⊙ = 4.83 {\displaystyle \scriptstyle M_{V_{\odot }}=4.83} , the visual luminosity can be calculated by L V ∗ L V ⊙ = 10 0.4 ( M V ⊙ − M V ∗ ) {\displaystyle \scriptstyle {\frac {L_{V_{\ast }}}{L_{V_{\odot }}}}=10^{0.4\left(M_{V_{\odot }}-M_{V_{\ast }}\right)}}
