Giant Star Undergoes Weight Loss

Astronomers solve a mystery surrounding a too-large star

The enormous star WOH G64 just got a serious weight reduction. The star is almost 2,000 times as large as our Sun, and it hangs out in the Large Magellanic Cloud, some 163,000 light years away from us. Until recently, scientists thought the mass of WOH G64 was 40 times that of the Sun. But that figure didn’t make sense, since the star seemed to be way too cold for something packing that much matter.

Now, using the cleverly named Very Large Telescope, astronomers have figured out that WOH G64 is half as bright as they thought, and significantly less massive. The star’s shape has also garnered interest: It is surrounded by a dense, donut-shaped collection of gas and dust. The scientists now guess that the star’s initial mass was 25 times that of the Sun, and that anywhere from three to 9 solar masses have been siphoned off into this waistband of dust and gas, otherwise known as a torus.

“Everything is huge about this system. The star itself is so big that it would fill almost all the space between the Sun and the orbit of Saturn,” says astronomer Keiichi Ohnaka. “And the torus that surrounds it is perhaps a light-year across!”