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Submission + - Another large Black hole in "our" Galaxy (arxiv.org)

RockDoctor writes: A recent paper on ArXiv reports a novel idea about the central regions of "our" galaxy.

Remember the hoopla a few years ago about radio-astronomical observations producing an "image" of our central black hole — or rather, an image of the accretion disc around the black hole — long designated by astronomers as "Sagittarius A*" (or SGR-A*)? If you remember the image published then, one thing should be striking — it's not very symmetrical. If you think about viewing a spinning object, then you'd expect to see something with a "mirror" symmetry plane where we would see the rotation axis (if someone had marked it). If anything, that published image has three bright spots on a fainter ring. And the spots are not even approximately the same brightness.

This paper suggests that the image we see is the result of the light (radio waves) from SGR-A* being "lensed" by another black hole, near (but not quite on) the line of sight between SGR-A* and us. By various modelling approaches, they then refine this idea to a "best-fit" of a black hole with mass around 1000 times the Sun, orbiting between the distance of the closest-observed star to SGR-A* ("S2" — most imaginative name, ever!), and around 10 times that distance. That's far enough to make a strong interaction with "S2" unlikely within the lifetime of S2 before it's accretion onto SGR-A*.)

The region around SGR-A* is crowded. Within 25 parsecs (~80 light years, the distance to Regulus [in the constellation Leo] or Merak [in the Great Bear]) there is around 4 times more mass in several millions of "normal" stars than in the SGR-A* black hole. Finding a large (not "super massive") black hole in such a concentration of matter shouldn't surprise anyone.

This proposed black hole is larger than anything which has been detected by gravitational waves (yet) ; but not immensely larger — only a factor of 15 or so. (The authors also anticipate the "what about these big black holes spiralling together?" question : quote "and the amplitude of gravitational waves generated by the binary black holes is negligible.")

Being so close to SGR-A*, the proposed black hole is likely to be moving rapidly across our line of sight. At the distance of "S2" it's orbital period would be around 26 years (but the "new" black hole is probably further out than than that). Which might be an explanation for some of the variability and "flickering" reported for SGR-A* ever since it's discovery.

As always, more observations are needed. Which, for SGR-A* are frequently being taken, so improving (or ruling out) this explanation should happen fairly quickly. But it's a very interesting, and fun, idea.

Submission + - Surado, formerly Slashdot Japan, is closing at the end of the month. (srad.jp) 1

AmiMoJo writes: Slashdot Japan was launched on May 28, 2001. On 2025/03/31, it will finally close. Since starting the site separated from the main Slashdot one, and eventually rebranded as "Surado", which was it's Japanese nickname.

Last year the site stopped posting new stories, and was subsequently unable to find a buyer. In a final story announcing the end, many users expressed their sadness and gratitude for all the years of service.

Comment Re:More basic (Score 1) 65

I am not sure why you say it is "particularly useless". It's not appropriate for storing large amounts of raw data. It is probably the best electronic format for storing actual documents, that is, things like engineering reports and analysis that have to be rendered properly and are primarily intended to be read by a person. It's still not nearly as good/safe as actual paper but if your application cannot tolerate math symbols showing as random font-substituted garbage, then it's about the only game in town.

Comment Re:More basic (Score 1) 65

We pass data files as text or FORTRAN binary, not PDF. We archive engineering reports as PDF, TIFF scans - or, the best, actual paper in a file cabinet, which so far has proven far and away the most reliable. PDF is hardly immune to corruption issues itself, depending on how you do it, it ALSO attempts to OCR or somehow convert information into something, and invariably corrupts the document. If it's not searchable, fine, at least it is *correct*.

Comment Re:More basic (Score 3, Insightful) 65

Right, it is more-or-less making images of each page. That's also the appeal of it, in that you don't ruin the formatting or render something incorrectly because you don't have a particular font, or some other local feature required to make something like WORD work. Even just the "font substitution" bug alone is enough to make people want to use PDF, and I haven't heard any better solution for archival documents.

We had a Platinum-level trouble ticket with MS for the font substitution issue, they concluded it was insoluble and that to keep our documents from getting corrupted, that we print it on paper, scan it as a TIFF, and save the TIFFS.

Aside from paper - which works fantastically well for this purpose, from the many examples I have at hand - I still don't see an answer that keeps searchable electronic documents intact over time and program version changes. And certainly not that are WYSIWYG when creating it in the first place. Various typesetting programs, - TeX and LaTex, formerly Runoff, etc, are just as prone to bit rot over version changes over many years/decades and also *torturous to use in the first place*.

Comment Re:Let's all register for Cause And Effect 101! (Score 3, Insightful) 94

No it isn't, nuclear reactors and power plants are pretty straightforward and similar to coal plants with the exception of the reactor. What costs are the unnecessary requirements, regulation, lawsuits, and everything else associated with it. All of which is the results of a bunch of know-nothing chicken littles that use every excuse to oppose it.

Comment Re:Let's all register for Cause And Effect 101! (Score 0, Troll) 94

You have nailed it, nuclear has never been costly, it's fighting tooth and nail for years/decades with the stupid f'ing hippies who chain themselves across the gates and file one legal brief after another that costs something.

      You have to understand that 99% of the people involved in the "environmental movement" know absolutely nothing about the topic, and also, do not care one whit for any practical solution to supplying energy.

      They don't believe in supplying energy, they believe in rolling back any progress and living in an agricultural commune. The fact that this destroys modern society is the goal. Oh, and incidentally, 4ish billion people will also have to somehow "go" because that's about what the Earth can support with a basic algricultrual revolution economy. Naturally, being morons, they mostly dont realize that, and the few that do, don't care.

Comment Re:I don't get it (Score 1) 111

Great analysis, exactly what I have come to expect from the usual denizens here. Designing and qualifying a complex life-critical system like this can't be done using your sorts of script-kiddie and hobbyist garbage, it is a very exacting and demanding process, you can't just slap stuff in there and then expect it to control a weapons systemÂ

Comment Re:Done. (Score 3, Insightful) 76

This is derived for a population size of infinity, in this cases, 150,000,000 might as well be infinity.

This is very simple, entry-level statistical theory. It;'s not just pulling things out of the air, it's mathematically true (under the assumptions of the derivation (like, normal distribution,etc). Stuff like this is not even a specialist type information, it's basic knowledge, in the same sense that you do not have to be an expert on planetary geology to know the earth is very roughly a ball.

        Brett

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