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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 3rd times the charm (Score 5, Interesting) 246

The important thing to remember with Starship is that the last two flights incorporated an entirely new design.with multiple experiments. These were fundamentally new rockets largely unlike their largely successful prior versions. Rather than a tweak of a nearly successful version to fix a few things we saw major changes one or two of which unfortunately is causing some catastrophic problems. They never got this far, but even just the tile system included probably a hundred different experiments.

Unfortunately since they didn't get that far it is also possible some of those tile experiments will cause catastrophic failure on re-entry if they try them all again. The thing about experiments is you need to to survive long enough to get to them. Hopefully some of those experiments were more about manufacturing rather than survivability so they can down select the most promising alternatives next ship in production. Regardless, we are still seeing a lot of changes each flight and those changes have the potential to not work.

Comment Only renamed the US area (Score 4, Informative) 371

The order renamed the area bounded by the US and the Continental shelf "extending to the seaward boundary with Mexico and Cuba in the area formerly named as the Gulf of Mexico"

That area is recognized by both countries to be under US jurisdiction by treaty. Mexico could retain the Gulf of Mexico name in their waters without conflicting names.

Comment Aerotolerant anaerobes (Score 1) 31

People are grasping at how O2 could be liberated from molecules, and photosynthesis is the only known way. What if the O2 were not liberated? What if it were always there but the other molecules were reduced?. This line of thinking got me to aerotolerant anaerobes as a possible mechanism for creating such deposits.

The list of requirements is: 1. A bunch of these guys trapped down there with your typical N2+O2+trace gas atmosphere typical of Earth, or perhaps some other O2 rich atmosphere that existed earlier in Earth's history. 2. They thrive down there, and all their competition dies off. 3. They're not just a little aerotolerant, but *very* aerotolerant, evolving to the point where they could survive until they run out of the other elements they need and of course 4. None of the other things down there react strongly with O2, and sedimentary rock layers trap that environment until now, when they crack and release the gas.

It's a lot of coincidences and takes time, but not more than the coincidence and time for life to evolve in the first place.

Comment Re: And the CEOâ(TM)s heart swelled up thre (Score 1) 236

How can you fix what government broke without government to at least unwind all the mistakes they(we) made? Yes, when government micromanages a free market it is bad, but putting in place simple regulations and then policing things like fraud is why we have government. You can't have a free market if the people can steal from one another without systematic use of violence to punish transgressors.

Comment Re: And the CEOâ(TM)s heart swelled up three (Score 1) 236

I am ok with an option out model for health like you can opt out of a 401k. But some minimum being required is probably more preferable overall. Most people need retirement savings beyond Social Security and will get sick before Medicare. Health Savings accounts should absolutely be an option to get whatever money the employer would have spent subsidizing the insurance plan.

Comment Re: And the CEOâ(TM)s heart swelled up three (Score 4, Interesting) 236

Yes, we need employers to stop forcing us into crappy plans. The government can play a role here. Make the market for health insurance work better and give people better options for using those employer funds to save up money tax free in health savings accounts. Don't require minimum withdrawals under a certain age so people can save up while they are healthier.

The employer's HR benefits administrators choosing the cheapest plan or the one with the best sales team isn't a free market and doesn't put the decision making into the hands of the people actually using the health insurance.

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