The Unifying Mystery of Black Hole Jets: Stellar and Supermassive Connections
SHOW NOTES Black hole jets follow one universal rule Adelle Goodwin (Curtin University / ICRAR, Forrest Research Foundation Fellow) and Andrew Mummery (Institute for Advanced Study, Princeton) show that supermassive black holes launch their outflows at the same critical accretion rate as stellar-mass black holes — about 2% of the Eddington limit — making accretion-outflow coupling scale-invariant across seven orders of magnitude in mass. Nature Astronomy, 17 September 2026. DOI: 10.1038/s41550-026-02951-1 JWST's Little Red Dots are black hole seeds caught mid-growth Sunmyon Chon, Shingo Hirano, Tomoaki Ishiyama, Seok-Jun Chang and Volker Springel ran fully cosmological radiation-hydrodynamic simulations on Japan's ATERUI III supercomputer and produced heavy black hole seeds of about a million solar masses, whose optically thick discs generate exactly the broad hydrogen emission seen in Little Red Dots. Nature 657, 621-625, 16 September 2026. DOI: 10.1038/s41586-026-10985-8 Earth's centre of mass moves about half as far as we thought Donald Argus, Felix Landerer and colleagues at NASA's Jet Propulsion Laboratory, with the University of Nevada, the University of Montana and the Helmholtz Centre for Geosciences, revise the annual oscillation between Earth's centre of mass and its centre of figure down from roughly 11 millimetres to about 4 to 5.5. Geophysical Journal International, ggag314. DOI: 10.1093/gji/ggag314 Two numbers explain the weather on a world 20 light-years away Merle Schrader and colleagues at Trinity College Dublin applied principal component analysis to one rotation of JWST spectroscopy of the brown dwarf SIMP 0136 and found two components — temperature and vertical cloud structure — account for all the detectable variability. Astronomy & Astrophysics, open access. DOI: 10.1051/0004-6361/202660109 The Sun goes blank With only active region AR4528 left on the Earth-facing disc and rotating out of view, the Sun was on the verge of its first spotless day since 24 February 2026 — which itself ended a 1,335-day run of continuous sunspot activity stretching back to June 2022. Skywatch: Venus at greatest brilliancy, first quarter Moon, Observe the Moon Night Venus reaches greatest brilliancy on 18 September at magnitude -4.8; the Moon reaches exact first quarter at 20:43 UTC the same day, setting up International Observe the Moon Night on Saturday 19 September. All times and altitudes in this segment were computed for Sydney, Los Angeles, New York and London. SKYWATCH — COMPUTED REFERENCE Computed in-session with PyEphem 4.2.1. Local times. Sydney on AEST (UTC+10); Los Angeles PDT; New York EDT; London BST. City Sunset Venus alt Venus sets Mercury Mars pre-dawn Sydney 17:45 39.2 deg 20:58 (3h13m) 16.4 deg (sets 1h20m) 20.4 deg Los Angeles 18:52 14.3 deg 20:10 (1h19m) 8.8 deg (sets 0h43m) 48.4 deg New York 18:56 10.3 deg 19:59 (1h03m) 7.0 deg (sets 0h38m) 46.1 deg London 19:04 3.6 deg 19:32 (0h28m) 3.9 deg (sets 0h26m) 40.6 deg · Venus greatest brilliancy: 18 September 2026, magnitude -4.8. Disc 39.6 arcsec, 26% illuminated. · By 22 September the disc has grown to 42.3 arcsec but the lit fraction has fallen to 22.7% — the two changes nearly cancel, which is why listings disagree on the date. The peak is genuinely flat. · Moon reaches exact first quarter 18 September at 20:43 UTC = 06:43 AEST Sat 19 Sep / 16:43 EDT Fri 18 / 13:43 PDT Fri 18 / 21:43 BST Fri 18. · Moon altitude at sunset: Sydney 81.6 deg (near overhead), Los Angeles 27.1 deg, New York 20.4 deg, London 9.4 deg. · International Observe the Moon Night: Saturday 19 September 2026. NASA event at the U.S. Space & Rocket Center, Huntsville, 5:30-8:00pm CST. · Pre-dawn Sat 19 Sep at nautical dawn — Jupiter: Los Angeles 26.4 deg, New York 25.1 deg, London 21.9 deg, Sydney 8.9 deg. · Mars-Jupiter separation: 22.9 deg on 18 Sep, 12.0 deg mid-October, 1.2 deg mid-November 2026. · Saturn is up essentially all night; sets 06:47 Sydney, 07:55 Los Angeles. Opposition 4 October 2026, disc 19.6 arcsec, rings approx 7 deg open. · September equinox: a single instant, 00:05:09 UTC on 23 September 2026 — evening of the 22nd in the Americas, mid-morning of the 23rd in Australia. · All figures computed in-session with PyEphem 4.2.1 for the four reference cities. Sydney is on AEST (UTC+10); daylight saving begins 4 October.
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