Astronomers have observed a binary star that potentially weighed 300 to 400 solar masses
https://phys.org/news/2013-04-candidate-massive-binary-star.htmlThe masses of these so-called Wolf-Rayet stars are up to 250 times the mass of the Sun. R144 is the visually brightest light source of this type in the star-forming region 30 Doradus and radiates strongly in X-rays. This was an indication that R144 is a binary star. This presumption has now been confirmed thanks to the discovery of periodic (orbital) changes in the spectrum.
