What does this number measure?
The distance separating us from the nearest star to the Sun. Proxima Centauri lies a little over four light-years away. We observe its light after several years of travel; this distance is distinct from the star's diameter.
Compare the stated dimensions
The comparison uses the number in each fact sheet: altitude, height, diameter, length or distance, depending on the reference. Two values in metres do not necessarily describe the same property.
Source and limitations
Catalogue order of magnitude; a source is provided, but this measurement has not been individually audited.
Sun–Proxima distance: schematic axis between the centres; stars enlarged and a break in scale symbolized in the middle.