| Right Ascension | 5 : 18.2 (h:m) |
|---|---|
| Declination | -69 : 15 (deg:m) |
| Distance | 169 (kly) |
| Visual brightness | 8.6 .. 11.7 (mag) |
| Spectral type | A0eq |
S Doradus is the brightest star in the Large Magellanic Cloud and was often claimed to be the brightest star known in the universe. It lies in the very young open cluster NGC 1910 which is located on the northern rim of the central bar of the cloud, measures 250 light years in diameter, and contains also a number of other extremely brigt stars.
The star S Doradus shows a spectrum which is very similar of the remarkable variable P Cygni, another variable of the same type. These stars are extremely massive, more than at least 60 solar masses. This results in an enormous luminosity, which first makes them use up their nuclear fuel very fast so that the lifetime of these stars cannot exceed a few million years, after which time they will explode as supernovae. Second, the luminosity makes up an enormous radiation pressure at the star's surface, tending to blowing away significant portions of the stellar mass both as a steady flow of very strong stellar winds and occasionally in the ejection of a gaseous enveloping shell.
The light curve of S Doradus, in addition, may point to a long period (40 year) eclipsing variable behaviour, according to Burnham.