“Teleos” is a nearly perfect spherical bubble. But what exactly it is and why it looks like this remains a mystery. Filipovic/Publications of the Astronomical Society of Australia/arXiv The universe favors spheres. Stars, planets, Earth, the moon, all are like this. But a team of scientists led by Miroslav Filipovic, an astrophysicist at the University of Western Sydney, recently said that a spherical bubble they had discovered in the Milky Way could hardly be explained by any theory. It is suspected to be a supernova remnant, but its appearance is too perfect and lacks many of the characteristics of a supernova remnant. Researchers call the bubble “Teleios”, which means “perfect” in Greek. ” “Teleos” is only visible in faint radio wavelengths. At present, people cannot even be sure how far it is from us. Some estimate that it is only 7,175 light-years away, while others believe that it is 25,114 light-years away. And the difference in distance means different sizes, and different understandings of the mechanism of its formation. “Teleos” has similarities to another strange phenomenon – “Odd Radio Circles”. But the “strange radio rings” that first appeared in 2019 are very different from it. “Strange Radio Rings” are much larger than “Teleos” – its diameter can reach a million light-years, which is 16 times that of our Milky Way Galaxy, and is not on the same order of magnitude at all. The researchers think that “Teleos” is most likely a supernova remnant – but if so, it must be a type of supernova remnant that no one has seen before. As the name suggests, a supernova remnant is the remnant of a supernova explosion. When a star reaches the end of its life, it explodes violently if certain conditions are met. The supernova that left “Teleos” may be a type Ia supernova. Type Ia supernovae are a type of supernova that do not cause the core of a massive star to collapse after running out of fuel for fusion, but occur in a special type of binary star. One of these binaries is a white dwarf – a white dwarf is the core of a low-mass star that is no longer fusing; the other is a star whose core is still fusing. This white dwarf is so close to its companion that it grabs a lot of material from its companion and accumulates it on itself. If it accumulates too much material beyond the critical point, it will explode. Researchers believe that Teleos may also be left behind by an extremely rare type Iax supernova. Such supernova explosions do not completely destroy the original white dwarf, but leave behind some remnants. Scientists call such remnants “zombie stars.” But there are problems with both possibilities. If Teleos was left behind by a type Ia supernova, it should theoretically produce X-rays. However, it did not. And if “Teleos” was left by an Iax supernova, then it should be closer, only 3,262 light-years away. Calculations show that if “Teleos” is 7,175 light-years away, then its diameter is about 46 light-years; if it is 25,114 light-years away, then its diameter is about 157 light-years. And if “Teleos” is a remnant of an Iax-type supernova, then its diameter is only about 11 light-years. At its distance, researchers did find a “zombie star” left behind by a suspected supernova. But another independent measurement shows that if “Teleos” is 11 light-years in diameter, then it is not actually at the distance of 3,262 light-years. The spherical bubble “Teleos” (lower left in the image) and its surroundings in the plane of the Milky Way galaxy. Filipovic/Publications of the Astronomical Society of Australia/arXiv In addition to the “uncertain” distance and size, it is also a mystery why “Teleos” is so round. “Teleos” is almost a perfect sphere. This may suggest that the eruption occurred in a nearly perfectly symmetrical form, so the gas and dust it threw would appear to be a nearly perfect sphere. However, this is not in line with people’s assumptions about type Ia or Iax supernovae. In nature, the shape of supernova explosions is actually asymmetric due to the influence of the surrounding environment and its own factors, so supernova remnants usually tend to be asymmetrical as well. So why was the supernova explosion that left “Teleos” so symmetrical? The researchers say that all the possibilities they can think of are facing challenges. In particular, it is puzzling that the X-rays predicted by theoretical models should not be observed. So far, it seems that “Teleos” is still the most likely supernova remnant, but in fact there is still no direct evidence to confirm either possibility.
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