What does this number measure?
A red supergiant whose photosphere expands and contracts. The disc shown represents its diameter, twice the adopted radius of 1456 nominal solar radii (1 nominal solar radius = 695 700 km). The value is a dated estimate, not an established size record. Jadlovský et al. (2026) find an average radius of 1 456 ± 108 solar radii in quiescence and 1 556 ± 110 during the active phase. This reference adopts the quiescent phase; these two averages do not bound its entire variability.
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
Jadlovský et al. (2026) find an average radius of 1 456 ± 108 solar radii in quiescence and 1 556 ± 110 during the active phase. This reference adopts the quiescent phase; these two averages do not bound its entire variability.
VX Sagittarii: artistic illustration of a stellar photosphere. A shared generic pattern for comparing diameters; neither a photograph nor a reconstruction of this star. The value and its uncertainties are given in the object information.