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Astronomers Discover Giant Ancient Stars in Milky Way (theguardian.com) 25

Astronomers have discovered a mysterious group of giant elderly stars at the heart of the Milky Way that are emitting solar system-sized clouds of dust and gas. The stars, which have been named "old smokers," sat quietly for many years, fading almost to invisibility, before suddenly puffing out vast clouds of smoke. The discovery was made during the monitoring of almost a billion stars in infrared light during a 10-year survey of the night sky. The Guardian: The astronomers had set out to capture rarely seen newborn stars -- known as protostars -- while undergoing the equivalent of a stellar growth spurt. During these periods, young stars rapidly acquire mass by gorging on surrounding star-forming gas, leading to a sudden increase in luminosity. The team tracked hundreds of millions of stars and identified 32 erupting protostars that increased in brightness at least 40-fold and in some cases more than 300-fold.

Another group of red giant stars near the centre of the Milky Way unexpectedly showed up in the analysis, however. When they were studied in more detail using the European Southern Observatory's Very Large Telescope, seven of the stars were deemed to be a new type of red giant star, which the researchers named "old smokers." Convection currents and instabilities within the star could trigger the release of enormous columns of smoke, Prof Philip Lucas of the University of Hertfordshire, who led the observations, suggested.

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Astronomers Discover Giant Ancient Stars in Milky Way

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  • by Impy the Impiuos Imp ( 442658 ) on Friday January 26, 2024 @11:14AM (#64189608) Journal

    Astronomers have discovered a mysterious group of giant elderly stars at the heart of the Milky Way that are emitting solar system-sized clouds of dust and gas.

    "The cloud measures...my god! 82 AUs in diameter!"

    Restore the grandeur of Vger!

  • When is the Sun going to flicker and belch? Kind of odd how the thing is so damn stable, is statistical mechanics so fucking reliable? Fucking Boltzmann what an ass.

    • by MightyMartian ( 840721 ) on Friday January 26, 2024 @12:18PM (#64189824) Journal

      Because it's a middle aged star, and in general, so long as they've got lots of hydrogen fuel, stars like the Sun are pretty well behaved. When the hydrogen supply finally begins to run out, in a few billion years, if there's anyone around, life will get a lot more uncomfortable.

    • Re: (Score:3, Funny)

      by iggymanz ( 596061 )

      red dwarfs flare violently, bigger stars become unstable after nearly exhausting their nuclear fuel. Our sun has billions of years to get that way but cheer up just the slow expansion of it will render Earth unfit for multicellular life in mere hundreds of millions of years.

    • Selection bias. If Sol were less stable we probably wouldn't exist.
  • They were the stars that were shaking their fists at the younger stars complaining how they ruined the galaxy
    • They were the stars that were shaking their fists at the younger stars complaining how they ruined the galaxy

      Sounds like ancient stars residing in an astrophysical retirement home.

      I can hear it now: Stay away from my Dark Matter you immature little ruffians !

    • by Tablizer ( 95088 )

      and git off my dust lane!

  • H. A. Rey, who wrote *the* book for fledgling astronomers, The Stars, said that the Aztecs believed the stars were a bunch of old men smoking cigars and swapping lies...Turns out they were right...
  • "Giant red star" implies it's the end-of-life of a relatively large star, which don't typically live that long, so how can they be "ancient"? I would consider "ancient" to be about 10 or more billion years old. They should be long gone into small white neutron stars or black holes. It did say "new kind of star", so maybe they don't know yet.

    • What if the universe is not only stranger than you imagine, but stranger than you can imagine?

    • Yes, I noticed that too - which is why I've got the Grauniad page opening in one tab, and I'm about to go off and hunt up the named research leader on Arx[which should be a Chi]iv.

      I've said it before, and I'll say it again - don't waste time reading the press release (or journalistic regurgitation of it). Go direct to the Friendly Paper.

      Which I'll now try to find.

  • by RockDoctor ( 15477 ) on Saturday January 27, 2024 @01:10AM (#64191716) Journal
    In this case, the paper is in MNRAS (Monthly Notices of the Royal Astronomical Society) [oup.com], though the paper is Open Access, so you can get the whole shebang from there as a PDF, if that's how you like your papers.

    It's a descriptive paper of 222 variable sources detected by a 9.5 year survey of the Galactic Bulge (that's the bright blob of the Milky Way, in and around the constellation of Sagittarius ; it's the central region of the galaxy). Many of the variable sources they detect fit into established categories (well, it's hardly the first survey of any part of the sky, so people should have come up with classifications already!), but ...

    Additionally, we report the discovery of a significant population of aperiodic late-type giant stars suffering deep extinction events, strongly clustered in the Nuclear Disc of the Milky Way.

    Which seem to be the novelty. However, possibly confusingly to journalists without a science background, they also make comments about commonalities observed in the class of "Young Stellar Objects" (YSOs) and how they accrete and expel matter - though maybe at different times. The two different classes seem to be confusing to the PR-writers. RTFP!

    The variability that they found in their target - YSOs - included multiple dimmings, inferred to be due to patchy distribution of circumstellar matter. (Supplementary information figure E1 : "Light curves of the eight dipping YSOs. The variation in these systems is thought to be due to variable extinction by circumstellar matter." That may not mean much to you, but to me it sounds like the irregular and sometimes deep dimmings seen in "Tabby's Star [slashdot.org]". See - Dyson sphere fan's - it hasn't been forgotten. Just reeled into a wider class of prosaic phenomena as an extreme example.

    But where do they mention "old smokers"? Nowhere - in the paper. Working their way through the variable objects they detected, they report

    Our initial classifications break down as follows: 70 CVs [Cataclysmic Variables], 40 YSOs, 38 microlensing events [a whole 'nother topic, but expected in a survey against the galactic core], 35 LPVs [Long Period Variables], 21 sources that we call âdipping giantsâ(TM), 10 sources that we classify as âunusualâ(TM) and eight transients denoted âsparseâ(TM), where there are too few detections over time to attempt an astrophysical classification.

    The "eight transients denoted âsparseâ(TM)," would seem to be the Press Release's "seven of the stars [...] deemed to be a new type of red giant star, which the researchers named 'old smokers'." The reader should note that one observation of a spectrum is normally sufficient to identify a star in the "red giant" phase of it's life ; but by the astronomer's own classification, these stars have too little data to be understood. (There is a silent "[comma] so far" in there ; there always is.)

    The wider significance of this possible discovery of a new class of stars is easily overstated though. The Press Release notes quote the team leader as saying that

    âoeThe discovery of a new type of star that throws off matter could have wider significance for the spread of heavy elements in the nuclear disc and metal-rich regions of other galaxies,â

    Which is certainly not untrue. But it doesn't mention that essentially all large stars are thought to lose significant amounts of mass in the later stages of their life, and the bigger the star, the more mass they lose. There are whole classes of star identified by their massive outflows of newly synthesised elements in the last millennia of their lives, such as

  • ...older stars have found themselves addicted, unable kick the habit, and unable to stop smoking.

    This is a terrible burden on intergalactic healthcare and a bad influence on a younger generation.

"Consequences, Schmonsequences, as long as I'm rich." -- Looney Tunes, Ali Baba Bunny (1957, Chuck Jones)

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