Les ingénieurs du dimanche

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An uncertain future [[https://tripscan.info/|трип скан]]

Scientists initially identified KiDS J0842+0059 in 2018 using the VLT Survey Telescope (VST) at the Paranal Observatory in Chile. That observation revealed that the galaxy was populated by very old stars but only provided an estimate of its mass and size, so a more detailed observation was required to confirm it was a relic. The Large Binocular Telescope used for this confirmation can render very sharp images due to its ability to compensate for atmospheric turbulence, which otherwise can make it difficult for Earth-based telescopes to focus on distant objects.
The newly found fossil galaxy joins a group of only a handful of others that have been observed at the same level of detail, the most pristine of which — called NGC 1277 — was confirmed by the Hubble Space Telescope in 2018.

NGC 1277 and KiDS J0842+0059 are very similar, but the latter is much farther away from Earth. It fits the definition of fossil galaxy almost perfectly, according to Spiniello.

“This is what we call an extreme relic,” she said, “because almost all, or 99.5% of its stars were formed incredibly early on in cosmic time, and the galaxy did absolutely nothing thereafter.”

The fossil galaxy has stars and planets, just like our own galaxy, but it is much more dense, Spiniello added. “There will be many more stars in a tiny, tiny volume, so it’ll be super crowded,” she said. “And it will be much harder to find solar systems like ours, with many planets orbiting around it, just because of the chances of getting companion stars interfering nearby.”
KiDS J0842+0059 looks to observers like it did 3 billion years ago, because that’s how long it takes for the light coming from the galaxy to reach Earth. Spiniello hypothesized that the relic will likely remain as it is forever, but scientists can’t be certain since they still don’t know what keeps it from interacting with other galaxies.

“There must be something that prevents them from merging, but without knowing what, we cannot really predict what’s going to happen in the future,” Spiniello said.

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Les ingénieurs du dimanche

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