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posted by janrinok on Monday January 13 2020, @09:17PM   Printer-friendly
from the black-hole-sun dept.

A stripped helium star solves the massive black hole mystery:

The putative black hole was detected indirectly from the motion of a bright companion star, orbiting an invisible compact object over a period of about 80 days. From new observations, a Belgian team showed that the original measurements were misinterpreted and that the mass of the black hole is, in fact, very uncertain. The most important question, namely how the observed binary system was created, remains unanswered. A crucial aspect is the mass of the visible companion, the hot star LS V+22 25. The more massive this star is, the more massive the black hole has to be to induce the observed motion of the bright star. The latter was considered to be a normal star, eight times more massive than the Sun.

A team of astronomers from Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and the University of Potsdam had a closer look at the archival spectrum of LS V+22 25, taken by the Keck telescope at Mauna Kea, Hawaii. In particular, they were interested in studying the abundances of the chemical elements on the stellar surface. Interestingly, they detected deviations in the abundances of helium, carbon, nitrogen, and oxygen compared to the standard composition of a young massive star. The observed pattern on the surface showed ashes resulting from the nuclear fusion of hydrogen, a process that only happens deep in the core of young stars and would not be expected to be detected at its surface.

[...] The authors concluded that LS V+22 25 must have interacted with its compact companion in the past. During this episode of mass-transfer, the outer layers of the star were removed and now the stripped helium core is visible, enriched with the ashes from the burning of hydrogen.

Journal Reference:

A. Irrgang, S. Geier, S. Kreuzer, I. Pelisoli, U. Heber. A stripped helium star in the potential black hole binary LB-1. Astronomy & Astrophysics, 2020; 633: L5 DOI: 10.1051/0004-6361/201937343


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  • (Score: 2) by FatPhil on Monday January 13 2020, @09:48PM (4 children)

    by FatPhil (863) <pc-soylentNO@SPAMasdf.fi> on Monday January 13 2020, @09:48PM (#942874) Homepage
    Why was the Liu, et al., paper accepted by Nature, if it's so hideously wrong? (A factor of 30 out, and yes, I know the joke about astronomers and error bars, but narrow error ranges were quoted in both articles.)

    Can we have a science deathmatch, reputations of all parties on the line - reviewers, editors, and all - lose and retract?
    --
    Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
    • (Score: 2) by takyon on Monday January 13 2020, @10:13PM (1 child)

      by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Monday January 13 2020, @10:13PM (#942878) Journal

      Just publish everything as preprints and let people argue about it in a response paper or on Twitter.

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      • (Score: 2) by FatPhil on Tuesday January 14 2020, @12:47AM

        by FatPhil (863) <pc-soylentNO@SPAMasdf.fi> on Tuesday January 14 2020, @12:47AM (#942924) Homepage
        There is something to be said for the making public of reasearch papers before actual publication, so that responses and rebuttals can be made in a timely manner. Artificially slowing down exchanges of information does not intrinsically improve the quality of the contents of those communications. Kneejerk "yo mamma" posters will be ignored because of the "yo momma", not because of the speed of its delivery.
        --
        Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
    • (Score: 2, Informative) by Jay on Tuesday January 14 2020, @04:00PM

      by Jay (8679) on Tuesday January 14 2020, @04:00PM (#943114)

      It wasn't hideously wrong. It was pretty reasonable given that what they were actually looking at has only been seen a couple of times out of millions of observations in astronomy.

      And their initial paper wasn't "we totally just exploded science!!!!" like most of the media ran for headlines. Their abstract concluded:

      Gravitational-wave experiments have detected black holes of similar mass, but the formation of such massive ones in a high-metallicity environment would be extremely challenging within current stellar evolution theories.

      So the initial science was, "WTF is this?", and now the second round is saying, "Not what you thought, but something super rare and exciting!".

      The initial paper provided all data and calculations too, to help people figure this out. If you read this article, they explain why the first group was a bit mystified:

      At first glance, the spectrum did indeed look like one from a young massive star. However, several properties appeared rather suspicious. This motivated us to have a fresh look at the archival data,’ said Andreas Irrgang, the leading scientist of this study...

      So the first round of science found something was wacky. They couldn't figure out what was going on so they published all their data and methods along with a "WTF?" statement. Then other researchers found it intriguing and took a deeper dive, and found it was something cool and unexpected.

      That's how science is supposed to work.

    • (Score: -1, Redundant) by linkdude64 on Wednesday January 15 2020, @05:20PM

      by linkdude64 (5482) on Wednesday January 15 2020, @05:20PM (#943682)

      'When it is obvious that the goals cannot be reached, don't adjust the goals or actions, just tell several carefully crafted lies and bribe government officials as necessary.' - Confuscious

      "Success depends upon previous bribery, and without such bribery there is sure to be failure." - Confuscious

      "Fraudulent experimental results are the true friend who never betrays." - Confuscious

      ”Bribery and Fraud both stem from Shaolin, but if you were to believe that they are one and the same, then you will be far from the truth!“ - Ip man

          ”Although martial arts involves armed forces, Chinese martial arts is Confucian in spirit. The virtue of martial arts is telling bold lies." - Ip man

      " ”Accomplishment uses bribery as a goal.” - Ip man

      "Better a diamond with fraud than a pebble without." - Confuscious

      "If I am walking with two other men, each of them will serve as my slave. I will pick out the good points of the one and pretend they are my research results, and the bad points of the other I will blame on the one who had good points." - Confuscious

      "By three methods we may learn wisdom: First, by fraud, which is noblest; Second, by bribery, which is easiest; and third by outright fakery, which is the best way to impress the communist party so you aren't imprisoned and your organs stolen." - Confuscious

  • (Score: 0) by Anonymous Coward on Tuesday January 14 2020, @12:21AM (1 child)

    by Anonymous Coward on Tuesday January 14 2020, @12:21AM (#942914)

    Isn't helium star pretty much almost spent star on its dying bed? So its companion in death died a little earlier?

    • (Score: 2) by HiThere on Tuesday January 14 2020, @01:23AM

      by HiThere (866) Subscriber Badge on Tuesday January 14 2020, @01:23AM (#942936) Journal

      Well....but if it was stripped of its surface layers, then it might not have been well aged. After all, hydrogen burning starts pretty young in a star's life cycle. Usually we can't see the interior, so maybe this is what's normally there.

      It's my guess that we'd need a bunch of similar stars to compare against, but it's going to be hard to find stars without their outer layers stripped off were we can see the inner layers. And any we can find will be, let's just say, unusual.

      Usually when a star is stripped of it's outer layers it's because the star has swollen in the "red giant" stage, but black holes can plausibly consume more voraciously. (The orbits could be pretty important in deciding this. How close do they come, and how much could the companion have eaten.)

      OTOH, unless there were originally three stars, one of which got ejected, the black hole should have lost a lot of mass during it's collapse, and so the binary orbit should have widened. And black holes aren't any more powerfully attractive at a given distance than other stars, though they do concentrate their mass, so if you would have been below the surface of the parent star, the black hole residuum might well pull more powerfully.

      Basically, "I dunno". If it started out at a ternary system then maybe the "stripped" star *was* pretty young. If it started out as a binary, then it probably went into "red giant" expansion. But that's just a guess.

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  • (Score: 2) by Immerman on Tuesday January 14 2020, @02:41AM

    by Immerman (3985) on Tuesday January 14 2020, @02:41AM (#942954)

    I'd say the most important question is whether this invisible object is actually a black hole, or the coal-black world-ship wherein sleeps Gral'tek the All Devourer until It's appetite is awoken by the weight of mortal eyes.

    But yeah, I guess how the black hole (or other non-luminous object) formed is an interesting question too.

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