KW Sagittarii


KW Sagittarii is a red supergiant, located approximately 1,900 parsecs away from our Sun in the direction of the constellation Sagittarius. It is one of the largest known stars. If placed at the center of the Solar System, the star's surface would engulf Mars.

Distance

A distance of 2,400 parsecs is based on the assumption of membership on the Sagittarius OB5 association. The parallax derived from the Hipparcos mission is negative so doesn't give much information about the distance except that it is likely to be large. The Gaia Data Release 2 parallax is and implies a distance of around. A calculation using a prior based on known galactic structure gives a distance of.

Characteristics

In 2005, Levesque calculate that the star has a bolometric luminosity of over and a radius around based on the assumption of an effective temperature of 3,700 K. In 2012, Marcaide calculate that the star has a bolometric luminosity of less than based on the measured flux and an assumed distance, and a radius around based on the measured angular diameter and luminosity. The effective temperature was then derived from the luminosity and radius.