A dazzling star system once feared as a potential “Death Star” has turned out to be much less threatening than scientists once thought—and even more mysterious.
Wolf-Rayet 104, a famous “pinwheel star” located in our galaxy, has been closely studied for years.
Now, new research led by astronomer Grant Hill from the W. M. Keck Observatory has confirmed that WR 104 is made up of two massive stars orbiting each other every 8 months.
Their powerful stellar winds crash into one another, creating a beautiful spiral of dust that glows in infrared light and spins like a cosmic pinwheel.
This glowing spiral, first captured by the Keck Observatory in 1999, amazed astronomers and raised eyebrows.
One of the two stars is a Wolf-Rayet star—an old, massive star with a strong wind rich in carbon.
The other is an even larger OB-type star, still burning hydrogen and producing a powerful wind of its own.
When the winds from these stars collide, they create carbon-based materials (often called “dust” by astronomers) that form the glowing spiral pattern we see from Earth.
But at the time of its discovery, there was a major concern: was WR 104 aiming a deadly gamma-ray burst (GRB) right at us?
Some scientists believed the system was facing Earth directly—like looking down at a spinning garden hose. If true, a future supernova from one of the stars could send a powerful GRB in our direction, with potentially devastating effects. That’s why WR 104 got its dramatic nickname: the “Death Star.”
Hill’s new research, published in the Monthly Notices of the Royal Astronomical Society, used data from three Keck instruments to take a closer look at the stars’ motion. By studying their light and measuring how they move, Hill made a surprising discovery.
Although the dust spiral appears to be spinning face-on from our view, the actual orbit of the stars is tilted by at least 30 to 40 degrees—not pointing directly at Earth after all. That means the chance of a gamma-ray burst hitting us is much lower than feared.
While this is reassuring news, it also raises new questions. Why is the dust spiral tilted differently from the stars’ orbit? Are there unknown forces or processes shaping the spiral? Scientists aren’t sure yet, but they’re excited to find out.
“This discovery is a great reminder that space is full of surprises,” said Hill. “Sometimes we find answers, but we also end up with even more mysteries to explore.”
WR 104 may no longer be the Death Star, but it’s certainly still a star full of secrets.
