WOH G64

WOH G64 is a red hypergiant star in the Large Magellanic Cloud satellite galaxy in the southern constellation of Dorado. It is 168,000 light years away from Earth and is one of the largest known stars, with a radius 1,540 times that of the Sun, or about 1.07 billion kilometres (7.14 AU), corresponding to a volume some 3.65 billion times bigger than the Sun. If placed at the center of the Solar System, the star's surface would engulf Jupiter.

History

The star was discovered in the 1970s by Westerlund, Olander and Hedin. Like NML Cygni, the "WOH" in the star's name comes from the names of its three discoverers, but in this case refers to a whole catalogue of giant and supergiant stars in the LMC. Westerlund also discovered another notable cool hypergiant star, Westerlund 1-26, found in the massive super star cluster Westerlund 1 in the constellation Ara.

Characteristics

The combination of the star's temperature and luminosity places it at the upper right corner of the Hertzsprung–Russell diagram. The star's evolved evolutionary state means that it can no longer hold on to its atmosphere due to low density, high radiation pressure, and the relatively opaque products of thermonuclear fusion. The intervening dust clouds makes the study of the star very difficult. It may be even possible that it has a bright hot companion, however there has been no confirmation of this observation. The strong stellar wind of WOH G64 has created a torus-shaped cloud roughly a light year in diameter containing 3-9 solar masses of expelled material.