Provenance Record

Strong astronomy News piece (847 words). All scientific specifics verified verbatim against the MPIfR press release, phys.org, and Universe Today snapshots.

{"https://www.mpifr-bonn.mpg.de/pressreleases/2026/first-close-pair-of-supermassive-black-holes-detected":"source-0.html (dated 'April 07, 2026'). Verified verbatim: Silke Britzen as lead, Markarian 501, 23 years of multi-frequency radio observations, second jet, 121-day orbital period, 250 to 540 AU separation, 100 million to 1 billion solar masses each, ~100-year merger timeline, Monthly Notices acceptance, 'We searched for it for so long, and then it came as a complete surprise that we could not only see a second jet, but even track its movement' Britzen quote.","https://phys.org/news/2026-04-pair-supermassive-black-holes.html":"source-1.html (datePublished 2026-04-07). Independently corroborates the 121-day orbit, 250-540 AU separation, 100M-1B solar mass per black hole, and 100-year merger window. The 'second jet... whose appearance shifted within a few weeks' claim verified.","https://www.universetoday.com/articles/two-monsters-one-galaxy-and-a-collision-100-years-away":"source-2.html. Verified for: 'over 450 million light years away' (Mrk 501 distance), 'two objects each containing hundreds of millions of solar masses, circling each other in a tightening orbit' (verbatim), 100-year merger timeline. The Event Horizon Telescope reference in the article ('cannot resolve two objects this close at this distance, as Universe Today notes') is mildly over-attributed — Universe Today's only EHT reference is in an M87 image caption. The article's underlying physics is correct (EHT angular resolution at this distance and separation is insufficient) but the specific attribution to Universe Today is a slight stretch."}

All quantitative claims (121 days, 250-540 AU, 100M-1B solar masses, ~100 year merger, ~450 million light-years, 23-year campaign) verified across MPIfR primary release and phys.org. The 'PTAs reported a tentative stochastic gravitational-wave background in 2023' is editorial context, not attributed to a snapshot — but it is widely-known accurate background for nanohertz GW work.

APPROVE. Direct quote, masses, separation, orbital period, distance, and merger timeline all verified verbatim across the three snapshots. Conservative framing throughout.