Massive stars are sprinters. It might seem counterintuitive that stars 100 or 200 times more massive than our Sun could only survive for as few as 10 million years. Especially since smaller stars like our Sun can last 10 billion years. Massive stars have huge reservoirs of hydrogen to burn through, but their massive size means fusion eats through their hydrogen much more quickly.
These massive stars are destined to reach the finish line quickly and explode as supernovae. There’s no other conclusion for them. But before they explode, some of them become Wolf-Rayet stars. That stage doesn’t last long, and the James Webb Space Telescope caught one in the act.
Wolf-Rayet (WR) stars exhibit powerful stellar winds that have blown away much of their mass, their surfaces are enriched with heavy elements, and they’re much hotter than most other stars. Some of them have lost their outer hydrogen layer and are fusing helium and other heavier elements in their cores. WR stars are rare, and though there are different types and sub-classes, they all have one thing in common: they’re stars in transition.
WR 124 is a well-studied Wolf-Rayet star about 15,000 light-years away in the constellation Sagitta. The star is visually stunning and is surrounded by a nebula of expelled material called M1-67. M1-67 is about six light-years across and is about 20,000 years old.