from the you-say-that-like-its-a-bad-thing dept.
https://mashable.com/article/space-solar-system-white-dwarf-discovery
Some 90 light-years away, the researchers spotted an over 10 billion-year old white dwarf star — meaning the remaining hot core of a dead star similar to the sun — that's surrounded by a graveyard of broken apart chunks of planets, called planetesimals. The faint star has pulled in debris from these objects. But this solar system is unlike anything around us. It teems with elements like lithium and potassium. Crucially, no planets in our solar system have such a composition.
[...] As noted above, this solar system is old. That means the white dwarf (called WDJ2147-4035) and its surrounding solar system formed, and died, before the sun and Earth were even born. In fact, the chunks of former planets around WDJ2147-4035 are the oldest planetesimals that have ever been found in our galaxy around a white dwarf, Elms noted.
They discovered this white dwarf, and another one of a similar age, using an observatory in space called Gaia. [...] In WDJ2147-4035, they found chemicals like lithium, potassium and sodium had accreted — or got pulled in by gravity and amassed around — the ancient star. White dwarfs are made of hydrogen or helium, so the rocky remains of planets were responsible for supplying the other unique elements, the researchers concluded (by running simulations of this solar system's evolution).
Interestingly, the other white dwarf (WDJ1922+0233) they discovered was significantly different than the mysterious one. It's more familiar. They determined this star had pulled in planetary debris that's similar to Earth's rocky crust. So although one solar system remains an anomaly, the other one shows that Earth isn't so unique in the cosmos: There are other solar systems out there somewhat like it.
These two solar systems, however, are filled with graveyards of former planets. Over 95 percent of stars, like the sun, evolve into white dwarfs. Near the end of their lives, they expand into colossal red giant giants, destroying or disrupting nearby objects. When our sun expands, it will engulf planets like Mercury, Venus, and maybe even Earth, before it sheds its outer layers. The red giants will leave behind relics of broken apart planets and moons. The remnant star itself will be a white dwarf.
This is our cosmic destiny. Just not for a long, long, long time.
Journal Reference:
Abbigail K Elms, Pier-Emmanuel Tremblay, Boris T Gänsicke, et al., Spectral analysis of ultra-cool white dwarfs polluted by planetary debris, MNRAS, 517, 2022. DOI: 10.1093/mnras/stac2908
(Score: 1, Insightful) by Anonymous Coward on Tuesday November 15 2022, @08:21PM
(Score: 2) by TheGratefulNet on Wednesday November 16 2022, @01:10PM
they mentioned lithium; which is likely very relevant to many of the readers of this site.
(.. reference loosely stolen from lawrence krauss' cosmology lectures)
"It is now safe to switch off your computer."
(Score: 2) by mcgrew on Wednesday November 16 2022, @05:06PM (1 child)
Admins get way too few thanks around here. Please keep up the good work!
mcgrewbooks.com mcgrew.info nooze.org
(Score: 3, Insightful) by hubie on Thursday November 17 2022, @12:21AM
And thanks to whomever submitted it!