Provenance Record

Well-structured News-category piece (917 words, within the 400-1200 range) with clear Overview / What We Know / What We Don't Know / Analysis / Sources sections. Neutral, non-sensational tone throughout; no AI self-reference; no editorializing beyond what the sources support.

All 4 sources were read from disk snapshots (gunzip + full-text extraction) under sources/2026-07/astronomers-identify-at2019ijn-as-a-possible-new-class-of-relativistic-cosmic-explosion-with-record-radio-afterglow/, with sha256 of each decompressed file independently recomputed and confirmed to match manifest.json before reading. (1) source-0.html.gz (phys.org, via Archive.org fallback, sha256 604192...c200bce confirmed) — read in full; confirms ZTF discovery date May 31, 2019, redshift ~0.27, dwarf-galaxy host, optical peak of -21.05 mag in 5.26 days, radio peaking far later and >1 order of magnitude brighter than known LFBOTs/SNe, IMBH mass ~132,000 solar masses, magnetar 'not completely ruled out,' and the paper's closing quote about a 'new class of relativistic optical transients.' Also surfaces the numeric discrepancy flagged by the contributor bot: Phys.org's human-written body text states the jet's kinetic energy as '700 sexdecillion ergs' (=7x10^53 erg) and its auto-generated LLM 'Gist' at the foot of the page independently restates it as '~7x10^54 erg [sic; text reads 7×10⁵³]' -- in both cases an imprecise, unqualified 'jet kinetic energy' framing that does not cleanly match any single value in the peer-reviewed paper (it lands closest to one intermediate sensitivity-check figure, not the paper's stated beaming-corrected or favored isotropic-equivalent values). Confirmed this figure does NOT appear anywhere in the submitted article -- the bot correctly declined to use the Phys.org-derived number and sourced all energy figures directly to the arXiv preprint text instead. (2) source-1.html.gz (iopscience.iop.org, sha256 941f50...810a6a1f confirmed) -- this snapshot FAILED to capture real content: it is a 'Radware Bot Manager Captcha' interstitial page (title tag literally reads 'Radware Bot Manager Captcha'), consistent with the redirected_domain: validate.perfdrive.com flag the automated script raised. Because the snapshot did not capture the actual article, I fell back to a live WebFetch of https://iopscience.iop.org/article/10.3847/2041-8213/ae732c as a last resort (explicitly noted here per policy) -- the live fetch succeeded and returned the genuine ApJL article text, independently confirming z=0.2729, peak radio luminosity 2.0x10^31 erg/s/Hz, isotropic-equivalent energy ~6.9x10^54 erg, viewing angle 38.9 deg, IMBH mass 1.32x10^5 solar masses, and the paper's closing statement that AT2019ijn represents a new class of relativistic transients. This corroborates the arXiv preprint content and confirms the ApJL-attributed claims in the article. (3) source-2.html.gz (arxiv.org/abs, sha256 6c49ca...9d1e6a12 confirmed) -- read in full; confirms exact author list (Hucheng Ding, Xinwen Shu, Luming Sun, Liangduan Liu, Lei Yang, Yunwei Yu, Xueguang Zhang, Ying Gu, Fangkun Peng, Fabao Zhang, Zhumao Zhang, Ningyu Tang), title, submission date, abstract figures (z=0.273, Mg=-21.1 in 5 days, radio peak at 640 days, viewing angle ~40 deg, IMBH ~10^5 Msun), and the ApJL journal reference / DOI matching the article's citation. (4) source-3.html.gz (arxiv full HTML text, sha256 7b84c3...5eee99a1 confirmed) -- read in full via plain-text extraction and targeted keyword search; this is the most heavily used source and every specific attributed to it was verified verbatim or near-verbatim, including: host stellar mass 2.04x10^8 Msun; peak magnitude -21.05+/-0.02 in 5.26+/-0.29 days; the exact quoted phrase 'at least two orders of magnitude brighter than known radio-bright fast blue optical transients and supernova explosions at similar epochs but comparable to jetted tidal disruption events'; radio flux rising from 5.97 to 8.61 mJy over 229 days with a decline lasting >=1690 days; VLA/RACS/VLASS/uGMRT/Keck-LRIS facility mentions; IMBH mass 1.32x10^5 Msun at viewing angle 38.9 deg (~39 deg); the verbatim quoted phrase 'unless the energy release is strongly collimated into a very small solid angle' attached to the isotropic-equivalent energy of ~10^54 erg; the beaming-corrected jet kinetic energy of 5.9x10^52 erg computed via E_K~0.5*theta_0^2*E_iso; the paper's closing sentence 'AT2019ijn represents a new class of relativistic optical transients that highlights the importance of radio surveys for discovering off-axis jetted events' (near-verbatim quote, article correctly omits internal citation markers); and the full comparison-object list (Sw J1644+57, Sw J1112-82, Sw J2058+05, AT2022cmc on-axis; Arp 299-B AT1, AT2018hyz off-axis). One issue found here, described below, concerns which of two adjacent energy figures the paper's 'compact central engine' interpretation is actually attached to.

One misattribution found, both specific and subordinate (not in headline/summary/lead). Article bullet: 'Separately, the team calculated a beaming-corrected jet kinetic energy of about 5.9x10^52 erg, which they say points to a compact central engine such as a magnetar or an accreting black hole.' The source text's actual sentence order is: '...the beaming corrected energy can be calculated as E_K ~ 0.5*theta_0^2*E_iso = 5.9x10^52 erg (Sfaradi et al., 2024). Results for other values of epsilon_B are summarized in Table 3. While assuming a higher magnetic field energy fraction of epsilon_B=10^-1 could lead to a decrease in the energy, the E_iso remains high at 6.7(+1.7/-1.1)x10^53 erg. Such a high jet kinetic energy indicates that the embedded energy source is a compact object, such as a magnetar or an accreting black hole...' -- i.e., the 'points to a compact central engine' conclusion follows and is grammatically anchored to the isotropic-equivalent energy remaining high across sensitivity checks (order 10^53-10^54 erg, consistent with the ~10^54 erg figure the article itself cites two bullets later in the magnetar paragraph), not to the smaller beaming-corrected E_K=5.9x10^52 erg figure the article pairs it with. The 5.9x10^52 erg number itself is accurately quoted and correctly labeled as the beaming-corrected value; only the causal attribution ('which they say points to...') is misplaced onto the wrong one of two adjacent figures. All other specifics, quotes, dates, facility names, and the paper's central thesis were verified accurate.

Substantively strong, well-sourced science reporting that correctly resolved a real numeric ambiguity in the underlying coverage (the Phys.org jet-energy figure) by deferring to the primary paper's own precise values. One subordinate misattribution -- pairing the paper's 'compact central engine' interpretation with the wrong one of two adjacent energy figures -- is exactly the kind of single, honestly-correctable issue the corrections mechanism exists for. Approved for publication with a corrections record.