What does this number measure?
A yellow hypergiant in an interacting binary system. The disc shown corresponds to the diameter, twice the adopted radius of 1315 nominal solar radii (1 nominal solar radius = 695 700 km). The value is a dated estimate, not an established size record. Equivalent radius of 1 315 ± 260 solar radii in 2014, for an adopted distance of 3.6 ± 0.5 kpc. The star is distorted and has a companion: the disc is an equivalent-diameter reference, not an exact spherical shape.
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
Equivalent radius of 1 315 ± 260 solar radii in 2014, for an adopted distance of 3.6 ± 0.5 kpc. The star is distorted and has a companion: the disc is an equivalent-diameter reference, not an exact spherical shape.
HR 5171 A: an artistic illustration of a stellar photosphere. Shared generic pattern for comparing diameters; not a photograph or a reconstruction of this star. The value and its uncertainties come from the entry.