Today, in questions you didn't know you needed the answer to: Is there such a thing as a perfect ball? And if there were, would it contain the secrets of the universe? To wit, a spherical object lurking in our galaxy is so perfectly round that astronomers can't explain how it was formed.Dubbed "Teleios" after the Greek word for "perfect," the object is what's known as a supernova remnant (SNR), a glowing cloud of hot gases and other material left behind after a massive star dies in a powerful explosion called a supernova. And it's definitely earned its nickname. According to the astronomers' findings, as reported in a pre-print study accepted for publication in Publications of the Astronomical Society of Australia, this is one of the most circular galactic SNRs ever found."The shape indicates Teleios has remained relatively untouched by its environment," said lead author Miroslav Filipovic, an astronomer at Western Sydney University, in an written with his colleagues earlier this year. "This presents us with an opportunity to make inferences about the initial supernova explosion, providing rare insight into one of the most energetic events in the universe."When a star goes supernova, it blasts all that stellar material into space in a tremendous release of energy bright enough to momentarily outshine even entire galaxies. The astronomers believe that Teleios is the result of a rare type of explosion — we're talking happening only once every 500 years in the Milky Way rare — called a type Ia supernova that occurs in binary star systems. When a smaller but far denser white dwarf siphons enough matter from its companion star whose orbit has crept too close, the stolen stellar material detonates in an epic thermonuclear explosion that obliterates both the stars.For something so symmetrical to emerge out of an event so violent is unusual, to put it mildly."The supernova remnant will be deformed by its environment over time. If one side of the explosion slams into an interstellar cloud, we'll see a squashed shape," explained Filipovic in the essay. "So, a near-perfect circle in a messy universe is a special find."Teleios was uncovered as part of the Evolutionary Map of the Universe (EMU) survey using the Australian Square Kilometer Array Pathfinder (ASKAP), an enormous radio telescope that's proving to be a powerful tool for finding SNRs that aren't visible in other wavelengths. Teleios, exclusively seen at radio-continuum frequencies, is one of them. Along with its perfect shape, it has one of the lowest surface brightnesses among all known galactic SNRs.The astronomers estimate that Teleios lies at a distance of either 2.2 or 7.7 kiloparsecs away (or approximately 7,100 or 25,100 light years). The uncertainty surrounding its distance means its age and size are hard to pin down, too. It's either on the younger side at less than 1,000 years old, or much older at over 10,000 years old. Likewise, it could be as small as 46 light years across, or as large as 157 light years. In any case, their findings place Teleios at a stage of its evolution called the Sedov-Taylor phase, during which the expansion of the SNR first begins to slow down, as it sweeps up additional mass from the interstellar medium of space. There's a catch, though: this process should produce detectable x-ray emissions, but the astronomers haven't see any.Maybe, the astronomers explored, Teleios is actually the remnant of an even rarer type of Ia supernova: a type Iax, in which the white dwarf partially survives as "zombie star." In that case, Teleios might be much closer at less than 3,200 light years away while being about 10.7 light years across.No hard answer, however, can be made from the data we have now. But this is just the beginning, and the astronomers are optimistic that more detailed observations in the future will one day help put this mystery to bed.Share This Article