
Mysterious ‘Perfect’ Sphere Discovered Deep in the Milky Way: A Supernova Remnant Unlike Any Other
Astronomers have stumbled upon a celestial enigma deep within the Milky Way: a nearly perfect spherical object dubbed Teleios, Greek for "perfect." This isn't your average star or planet; it's a supernova remnant (SNR), the expanding shell of gas and dust from a massive stellar explosion. But Teleios stands out because of its exceptional symmetry, challenging our understanding of how these remnants typically form.

The discovery, led by astrophysicist Miroslav Filipović at Western Sydney University, was accidental. While scanning images from the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope, Filipović noticed Teleios's unusually circular shape. "Its perfectly circular shape was unusual, and so I investigated further," Filipović told Space.com. Its shape boasts a circularity score of 95.4%, making it one of the most symmetric SNRs ever found.
Why is this perfect sphere so intriguing? While SNR models often suggest a circular shape, real-world remnants are typically distorted by asymmetries in the initial explosion or interference from the surrounding environment. Filipović notes, "What makes Teleios' shape so remarkable is that it displays none of these asymmetries."
The key to Teleios's pristine form may lie in its location. Situated 2.2 degrees below the Galactic Plane, it resides in a region with significantly less interstellar gas and dust. This sparse environment could have allowed the remnant to expand undisturbed for millennia.

Adding to the mystery, Teleios emits primarily in radio wavelengths, with only a faint hint of hydrogen-alpha emissions. This is unusual, as most SNRs are visible across multiple frequencies. This characteristic makes it difficult to determine the type of supernova that birthed Teleios. The most likely candidate is a Type Ia supernova, a white dwarf explosion in a binary star system. However, the data doesn't perfectly align with this model.
Estimates place Teleios between 7,175 and 25,114 light-years from Earth, spanning either 46 or 157 light-years in diameter, depending on the distance. Regardless of its exact size, one thing is certain: Teleios presents a unique opportunity to study the evolution of supernova remnants in a relatively undisturbed environment.
The discovery of Teleios comes at a time when radio astronomy is experiencing a golden age, with new instruments like ASKAP and MeerKAT opening up possibilities for groundbreaking discoveries. Further research will be crucial to unravelling the remaining mysteries surrounding this celestial sphere.
What do you think created this near-perfect explosion? Share your thoughts and theories in the comments below!