5.3 a₀ (Bohr radius) is equal to 0.00000000000000000000000002964506205728106 ly (light-year). To convert from Bohr radius to light-year, multiply by 0.000000000000000000000000005593407935336049 or divide by 178,781,882,451,761,600,000,000,000.
physical constant; the most probable distance between an electron and the nucleus in a nonrelativistic model of the hydrogen atom with infinitely heavy nucleus