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Submission + - French troops boarded Russian tanker (dailymail.co.uk)

Submitted by schwit1
schwit1 writes: French troops have boarded the deck of a tanker alleged to be from Russia's 'shadow fleet' and suspected of involvement in drone flights over Denmark last month.

Submission + - An Online Group Says It's Behind a Campus Swatting Wave (nytimes.com)

Submitted by schwit1
schwit1 writes: Members of the group offered on Telegram to draw armed officers to schools, malls and airports, though their claims are unverified. Such false emergency calls have disrupted campus life in recent days.

An online group said that it was behind a number of recent hoax emergency calls that drew a heavy law enforcement response to college campuses across the United States and were timed to coincide with the start of the school year.

The group, which calls itself Purgatory, highlighted news media coverage of the recent hoaxes in a public-facing channel on Telegram, an encrypted messaging service often used by criminals.

The online group is suspected of being connected to several of the episodes, including reports of shootings, according to cybersecurity experts, law enforcement agencies and the group members’ own posts in a social media chat. The group’s claims could not be independently verified.

Federal authorities previously connected the same network to a series of bomb scares and bogus shooting reports in early 2024, for which three men pleaded guilty this year.

The spreading of false reports — a practice known as swatting — is intended to sow fear and chaos at educational and governmental institutions, as well as commercial places. Some swatting episodes have focused on the homes of politicians and other famous people.

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

Submitted by RockDoctor
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.

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