What does this number measure?
A red hypergiant surrounded by an envelope of gas and dust. The disc shown represents its diameter, twice the adopted radius of 1420 nominal solar radii (1 nominal solar radius = 695 700 km). The value is a dated estimate, not an established size record. The Rosseland photospheric radius is 1 420 ± 120 solar radii in Wittkowski et al. (2012); the molecular and dusty envelope is not included in this 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
Rosseland photospheric radius of 1 420 ± 120 solar radii in Wittkowski et al. (2012); the molecular and dusty envelope is not included in this diameter.
VY Canis Majoris: artistic illustration of a stellar photosphere. A shared generic pattern is used to compare diameters; this is neither a photograph nor a reconstruction of this star. The value and its uncertainties come from the object entry.