An illustration of the so-called “Death Star” known as Wolf-Rayet 104 which appears like a cosmic pinwheel. | Credit: U.C. Berkeley Space Sciences Laboratory/W. M. Keck Observatory
Cosmic Pinwheel “Death Star” Less Threatening Than Previously Thought
A celestial formation dubbed the “cosmic pinwheel,” once feared by astronomers for its potential to bombard Earth with deadly gamma radiation, is likely less perilous than initially believed, according to new research.
Understanding Wolf-Rayet 104
Located approximately 8,000 light-years from Earth in the Sagittarius constellation, the heart of this cosmic pinwheel comprises a binary system of two massive, scorching stars. Observations over the last two decades indicate that substantial gas plumes, expelled from both stars, interact within the expansive space separating them, resulting in a spiraling stream of heated gas and dust visible in the cosmos.
Previous Gamma-Ray Concerns
Earlier investigations suggested that Earth is positioned along the axis of this system, known scientifically as Wolf-Rayet 104, raising apprehensions about potential exposure to intense gamma rays unleashed during the stars’ eventual supernovae. This perceived threat led to the system being ominously dubbed the “Death Star.”
New Study Reveals Tilted Orbit
A recent analysis of data acquired at the Keck Observatory in Hawai’i, focusing on the velocities of the two massive stars, their orbital paths, and spectral characteristics stemming from the colliding stellar winds, indicates that the stars’ orbits are inclined at a 30 to 40-degree angle relative to Earth. This tilt significantly diminishes the likelihood of a gamma-ray threat compared to prior estimations.
Grant Hill, the study’s author from Keck Observatory, stated, “Initially, I anticipated that the primary focus would be the interacting stellar winds, with a face-on orbit assumed. However, I encountered a surprising revelation – the orbit is inclined by a minimum of 30 to 40 degrees from our line of sight.”
An infrared image of Wolf-Rayet 104 captured by Keck Observatory’s NIRC instrument in 1998 | Credit: U.C. Berkeley Space Sciences Laboratory/W. M. Keck Observatory
Reduced Threat to Earth
This altered understanding of Wolf-Rayet 104’s orientation suggests a significantly decreased probability of Earth encountering harmful gamma-ray bursts from this system.
Unresolved Puzzle: Dust Spiral Misalignment
These findings have also presented astronomers with an intriguing conundrum: the discrepancy between the seemingly face-on dust spiral and the now-established tilted stellar orbit.
According to the new study, this discrepancy may suggest more intricate physics are involved, potentially including previously unidentified processes capable of displacing the dust spiral from the orbital plane.
Further Reading:
- James Webb Space Telescope Detects Red Dots Fueling Black Holes
- James Webb Telescope Observes Planet-Forming Dust Shells Traversing Space
- New X-Ray Space Telescope Uncovers ‘Hidden Black Hole’ Engulfing Star
Continued Mysteries in Astronomy
Hill concluded, “This is a prime illustration of how astronomical research often leads to unexpected mysteries. Ultimately, these surprises deepen our understanding of physics and the cosmos. Wolf-Rayet 104, it seems, still holds undiscovered secrets.”
The research findings were published in the November issue of the journal Monthly Notices of the Royal Astronomical Society.