Space Time
Also known as NGC 6888, Caldwell 27, Sh2-105.
One record per aspect. The origin says what kind of thing each value is; the source says where it came from; the limit says what it cannot tell you.
Crescent Nebula image-field center is placed at J2000 RA 20.2 h, Dec 38.7° in Cygnus, at an adopted distance of 5,000 light-years.
Crescent Nebula (stellar outflow nebula; central source Crescent Nebula, illuminating stellar system): projected footprint at the adopted distance 35.3 × 36.3 light-years; outer radius used for arrival 18.2 light-years.
Emission-line palette: hydrogen-alpha red, oxygen blue and sulfur yellow. The original wide field is preserved in Evidence; the close-view aperture emphasizes the Crescent. Projected structure follows the credited observation at its published angular scale and an approximate adopted distance. Shallow depth is illustrative, not measured tomography. The source palette is preserved; brightness is adjusted for the navigable view.