Three point sources of roughly 16th magnitude within 10 arcseconds of each other appear on a POSS-I exposure of 19 July 1952 and are absent from the consecutive exposure taken within the hour, and from all subsequent imaging down to magnitude 25.5.

Peer-reviewed with deep modern follow-up and independent pipeline recovery, but single-team and single plate lineage, with no physical inspection of the 1952 material published.

The 1952 multi-source event is supported by peer-reviewed detection, deep modern follow-up showing no recurrence, and recovery by an independent extraction pipeline. The strongest opposing consideration is that everything known about this event relies on the same digitized Palomar copy lineage, and no physical inspection of the original plate material has been published.

The July 1952 triple transient is documented in a peer-reviewed MNRAS paper with deep 10.4-m follow-up imaging confirming the absence of persistent sources down to magnitude 25.5 (TRN-E007), and the detections are independently recovered by Hayes’s pipeline (TRN-E008). This supports the occurrence of three point sources in one exposure and their absence in a consecutive one and later data. However, unlike the 1950 nine, there is no published independent physical inspection of the plate material, and all information comes from the proponent team and digitized copies, which slightly lowers confidence relative to TRN-C001. The strongest opposing consideration is that the event lies on the same copy lineage and could be subject to similar unmeasured defect mechanisms, but that does not directly contradict the observational claim.

The July 1952 triple is peer-reviewed with 2023 10.4-m follow-up to magnitude 25.5, and Hayes independently recovers all three sources; vanishing within about fifty minutes is therefore a real feature of the digitized record. Unlike the 1950 nine, there is no published physical inspection of surviving glass, and characterization is still proponent-team plus one software recovery on the same Palomar copy lineage. The strongest opposing consideration is morphological non-uniformity: the isolated 1952 source looks like comparison stars, so the two canonical events do not even share a profile signature.

A peer-reviewed report of a bright triple present on one 1952 exposure and gone within about fifty minutes, with 2023 Gran Telescopio Canarias imaging to magnitude 25.5 and independent 3-of-3 recovery by the Hayes pipeline. The strongest opposing consideration: everything known about it passes through the same proponent team and the same Palomar copy lineage, no published physical inspection of the plate material exists, and — awkwardly — the isolated source's profile looks like ordinary stars, unlike the sharp 1950 nine, so the two canonical events are not morphologically uniform. As an observation it is well supported; as evidence for any particular origin it remains one lineage and one team's characterization.

Peer-reviewed in MNRAS with 10.4-m follow-up to r ≈ 25.5 confirming nothing at the positions today, and all three detections independently recovered by the Hayes pipeline from the digitized data without reference to the original team's lists. That combination secures the detections as features of the plate material and their absence from later imaging. The strongest opposing consideration is provenance depth: characterization, photometry and the "vanished within 50 minutes" inference all come from one proponent team working the same Palomar copy lineage, with no published physical inspection of the 1952 glass — so the numbers (~16 mag, 10 arcsec, >10 mag dimming) rest on a single calibration chain.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and now physically confirmed on a Harvard copy plate with co-presence in the original survey digitization (TRN-E022). Presence on that event's original negative is still inferred rather than observed.

Peer-reviewed with deep follow-up (TRN-E007) and independent pipeline recovery (TRN-E008), but still a single material lineage with no physical inspection of the 1952 plate. No new material bears on it.

Peer-reviewed with deep 2023 follow-up (TRN-E007) and independent pipeline recovery (TRN-E008), but single-team, same digitized lineage, and no physical inspection of the 1952 material published.

Peer-reviewed with deep modern follow-up (TRN-E007) and independent pipeline recovery (TRN-E008), but single lineage with no physical inspection of the 1952 material; TRN-E018 extends the aligned-multiple pattern without strengthening this specific observation.

The July 1952 triple transient is well documented in the peer-reviewed literature, has been successfully recovered by an independent extraction pipeline, and is confirmed to lack any modern counterparts in deep 2023 follow-up imaging. Recent manuscript reports also confirm its presence in the original survey digitization and on a Harvard copy plate, lending further physical credence. The strongest opposing consideration is that the most isolated of these three marks morphologically resembles standard comparison stars, contradicting the "sharper-than-stars" argument applied to the 1950 event and fracturing the uniformity of the proposed flash hypothesis.

The July 1952 triple transient is supported by peer-reviewed reporting and modern deep follow-up confirming the sources' absence, and the marks are reproducibly found by an independent extraction pipeline. The strongest opposing consideration is that, unlike the 1950 event, there is no published physical inspection of the surviving glass material to rule out digital or scanner artifacts, and it relies on the same digitized Palomar copy lineage.

The 1952 triple is described in a peer-reviewed MNRAS paper with two consecutive exposures showing appearance and disappearance within ~50 minutes, and deep 2023 follow-up to r~25.5 shows no persistent sources (TRN-E007). Hayes’s independent pipeline recovers all three detections at the reported positions (TRN-E008), and Yang & Villarroel confirm presence on a Harvard copy plate and in the original survey digitization (TRN-E022). These converging lines support the observational claim. The main opposing issue is that no published microscopy of the original negative exists for this event, and one of the three has a stellar-like profile rather than the sharp morphology of the 1950 nine (TRN-E007), complicating uniform explanations.

Solano et al. 2024 present the July 1952 triple event with modern deep follow-up to r~25.5, showing three ~16th magnitude point sources present on one plate and absent on an adjacent exposure and all later imaging (TRN-E007). The canonical triple is independently recovered by the Hayes pipeline (TRN-E008), corroborating its presence in the digitized data. The strongest opposing consideration is that, unlike the 1950 event, no published independent physical inspection of the original or copy plates exists, so the characterization currently rests only on proponent-team analyses within the same copy lineage.

The 2024 MNRAS paper reports three roughly 16th-magnitude point sources within 10 arcsec on one 19 July 1952 exposure, gone on the consecutive exposure about 50 minutes later, and absent in 2023 GTC imaging to magnitude 25.5 (TRN-E007); Hayes recovers all three (TRN-E008). Yang reports the triple on a Harvard copy plate and in the original survey digitization (TRN-E022). The strongest opposing consideration is morphological and genealogical: the isolated source looks like comparison stars rather than the sharp 1950 nine, no published inspection of that event's original telescope negative exists, and everything still sits in the Palomar copy family.

Solano et al. report three roughly 16th-magnitude sources within 10 arcsec on the 19 July 1952 exposure, gone on the consecutive exposure within the hour, and absent to magnitude 25.5 in 2023 GTC imaging; Hayes recovers all three. This is a second multi-source event with modern follow-up, which any single-plate accident story must also explain. Strongest opposing consideration: everything known passes through the same digitized Palomar copy lineage, there is no published physical inspection of the 1952 glass, and the isolated source's star-like profile makes the two canonical events morphologically non-uniform.

Peer-reviewed with modern 10.4-m follow-up to magnitude 25.5 (E007), recovered three-of-three by the independent Hayes pipeline (E008), and now reported present on a Harvard copy plate and in the original survey digitization (E022) — the triple exists and is not confined to one scan. It remains weaker than C001: no critic-side physical inspection has been published, the characterization is entirely the proponent team's, and the E022 examination for this event used copy material rather than the original negative. The strongest opposing consideration is internal: the isolated source's profile resembles ordinary stars, unlike the sharp 1950 nine, so the two canonical events are not morphologically uniform and any single mechanism must accommodate both. Well supported, moderate confidence.

The triple is peer-reviewed with deep modern follow-up (GTC to magnitude 25.5 in 2023), and Hayes's independent pipeline recovers all three sources, so the core observation — three ~16th-magnitude points, gone within the hour, nothing there now — is solidly documented on the digitized material. The strongest opposing consideration is provenance and uniformity: everything passes through the same Palomar copy lineage as the 1950 event, no physical inspection of the 1952 plate material has been published, the characterization comes entirely from the proponent team, and the isolated source's star-like profile sits awkwardly beside the distinctly sharp 1950 nine — the canonical events are not morphologically uniform, which any single mechanism must eventually explain. Well supported on the digitized record, held at moderate confidence by the single-team, single-lineage character of the evidence.

Peer-reviewed with 10.4-m follow-up to magnitude 25.5 (TRN-E007), independently recovered three-of-three by a from-scratch pipeline (TRN-E008), and now reported present on a Harvard copy plate and in the original survey digitization (TRN-E022). Confidence stops short of high because everything known about the triple originates with the proponent team, no examination of the original 1952 negative has been made (its presence there is inferred from co-presence in the original digitization), and the disappearance timescale rests on exactly two consecutive exposures. The strongest opposing consideration is TRN-E007's own profile finding — the isolated member looks like the comparison stars, unlike the sharp 1950 nine — showing the canonical events are not morphologically uniform, which any single mechanism, exotic or mundane, must eventually reconcile.

The triple is peer-reviewed with 10.4-m follow-up to r ≈ 25.5 (TRN-E007), and all three sources are independently recovered by Hayes's pipeline from the digitized data (TRN-E008), so the detections are not a private-software artifact. The strongest opposing consideration is that everything known about this event passes through the same Palomar copy lineage as the 1950 nine, with no published physical inspection of the 1952 plate material, and the paper's own profile finding — the isolated member looks like the comparison stars — shows the canonical events are not morphologically uniform, which complicates any single-mechanism story on either side. The claim as stated is about what the plates show, and that is well documented; confidence is moderate rather than high because only the proponent team has handled the material.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy plate with co-presence in the original survey digitization (TRN-E022). The original 1952 negative itself remains uninspected, which caps confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and now physically confirmed on a Harvard copy plate with co-presence in the original survey digitization (TRN-E022) — though the original 1952 negative itself remains uninspected.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and physically present on a Harvard copy plate with co-presence in the original survey digitization (TRN-E022). The original 1952 negative itself remains uninspected, which caps confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy plate with co-presence in the original survey digitization (TRN-E022). The original 1952 negative itself remains uninspected, which caps confidence.

The 1952 triple transient event is detailed in a peer-reviewed paper, was followed up by deep modern imaging, and was successfully recovered by an independent detection pipeline. The strongest opposing consideration is that, unlike the 1950 event, there is no published independent physical inspection of the surviving original plate material to definitively rule out a copy defect.

Solano et al. (TRN‑E007) describe the July 1952 triple event with two consecutive plates limiting the duration to under an hour, deep 2023 follow‑up to r≈25.5, and star-like profiles for the isolated source; Hayes’s pipeline recovers all three candidates (TRN‑E008), and Yang & Villarroel confirm the event is not confined to single copy material (TRN‑E022, TRN‑E023). This supports the existence of a second canonical multi-source event. The strongest opposing consideration is that, unlike the 1950 nine, no published microscopy of the original 1952 negative exists, so origin in a plate or copy defect remains an open, unexamined alternative.

Solano et al. 2024 report three ~16 mag point sources within 10 arcsec on the 19 July 1952 exposure, gone on the consecutive exposure about fifty minutes later and absent through 2023 GTC imaging to magnitude 25.5; Hayes independently recovers all three. That is a second multi-source, rapidly vanishing event on the same plate family, with modern follow-up. The strongest opposing consideration is that almost everything known still passes through the digitized Palomar copy lineage and the proponent team: no published inspection of the original 1952 negative exists, the Yang examination was of a Harvard copy plus the survey digitization, and the isolated source’s star-like profile already shows the two “canonical” events are not morphologically uniform.

The July 1952 triple is peer-reviewed (MNRAS), independently recovered by the Hayes pipeline (3 of 3), and has deep 2023 follow-up (mag 25.5) confirming the sources never returned; the microscopy manuscript further reports it on the Harvard copy plate and in the original survey digitization (TRN-E022), which strands the copy-only account for this event too. Confidence is moderate rather than high because every characterization still comes from the proponent team plus one independent software recovery on the same lineage, and no physical inspection of the original 1952 negative has been published — presence there is inferred, not observed. The strongest opposing consideration is morphological non-uniformity: the isolated triple member looks like a star while the 1950 nine are distinctly sharp, which any single-mechanism account (flash or defect) must accommodate.

Peer-reviewed with modern 10.4-m follow-up reaching magnitude 25.5, and the three detections are independently recovered by the Hayes pipeline, which removes private-software error as an explanation for the digitization-level marks; the microscopy manuscript further places the candidate on a Harvard copy plate and in the original survey digitization. Confidence is moderate rather than high because the load-bearing comparison — presence on one exposure and absence on the consecutive one within the hour — comes entirely from the proponent team, and no published physical inspection of the 1952 original negative exists. The strongest opposing consideration is that everything known about this event still passes through one plate lineage and one team's characterization, so an unnoticed plate-level or handling artifact affecting a single exposure remains available.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy plate with co-presence in the original survey digitization (TRN-E022). The original 1952 negative itself remains uninspected, which caps confidence.

The 1952 triple transient is documented in a peer-reviewed publication with deep modern follow-up confirming the sources have vanished (TRN-E007). The features are recovered by independent extraction pipelines (TRN-E008), and unreviewed microscopy confirms their presence in the original survey digitization (TRN-E022). The strongest opposing consideration is that, unlike the 1950 event, there is no published independent physical inspection of the original 1952 negative, and the sources' stellar-like profiles conflict with the extreme sharpness expected of brief flashes.

The 1952 triple transient is described in a peer-reviewed paper with deep modern follow-up (TRN-E007) and independently recovered in Hayes’s pipeline (TRN-E008), both finding three ~16th-magnitude point-like sources that appear on one plate and vanish within an hour with no modern counterparts down to ~25.5 mag. Yang & Villarroel show that the event is present both on at least one copy plate and in the original survey digitization (TRN-E022), further solidifying its observational status. The main opposing consideration is the lack of a published inspection of the original negative for this event, so a residual possibility remains that its apparent behaviour reflects copy-chain defects or very local plate issues, though that seems unlikely given the consistency across representations.

Solano et al. 2024 report three ~16 mag point sources within 10 arcsec on one 19 July 1952 exposure, gone within the hour, and blank in 2023 GTC imaging to magnitude 25.5; Hayes recovers all three; Yang finds the candidate on a Harvard copy and in the original survey digitization. That is a second multi-source, multi-epoch non-recovery, peer-reviewed with modern follow-up. Strongest opposing consideration: the isolated source's profile looks like comparison stars rather than the sharp 1950 nine, there is no published inspection of the 1952 original negative, and the whole characterization still sits in the Palomar copy lineage.

Peer-reviewed with deep modern follow-up to magnitude 25.5, independently recovered three-for-three by the Hayes pipeline, and reported present on both Harvard copy material and the original survey digitization (TRN-E022). The strongest opposing consideration is that everything passes through the same Palomar lineage and one team: no published physical inspection of the 1952 plate exists, and the manuscript's examination was of a copy, with original-negative presence inferred from co-presence in the digitization. Also load-bearing against any single-mechanism story: the isolated source's star-like profile differs from the sharp 1950 nine, so the canonical events are not morphologically uniform.

The event is peer-reviewed with 10.4-m follow-up to r ≈ 25.5 (TRN-E007), independently recovered 3 of 3 by an outside pipeline (TRN-E008), and TRN-E022 reports it present both on a Harvard copy plate and in the original survey digitization. Confidence is moderate rather than high because no physical inspection of the 1952 original negative has been performed — its presence there is inferred, not observed — and the characterization of the event (including the vanishing within the consecutive exposure) comes from the proponent team on a single plate lineage. The strongest opposing consideration is internal, noted in TRN-E007 itself: the most isolated of the three has a profile nearly identical to comparison stars, unlike the sharp 1950 nine, so the two canonical events are not morphologically uniform and no single mechanism — flash or defect — comfortably covers both.

Peer-reviewed with deep modern follow-up (TRN-E007), independently recovered (TRN-E008), present on a Harvard copy plate with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, capping confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), present on a Harvard copy with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, capping confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, capping confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy plate with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, capping confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy plate with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, capping confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy plate with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, which caps confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy plate with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, capping confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy plate with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, capping confidence.

The 1952 triple transient is peer-reviewed, supported by deep modern follow-up imaging confirming the absence of the sources today, and recovered by an independent pipeline. However, no independent physical inspection of the original 1952 plate material has been published, leaving it vulnerable to the same copy-defect hypotheses that plagued the 1950 event prior to recent microscopy.

The Solano et al. paper (peer-reviewed) reports the 1952 bright triple, its absence on a consecutive exposure, and deep modern follow-up to r≈25.5 showing no persistent sources; Hayes’s pipeline independently recovers all three detections. This convergent support makes the basic observational claim credible. The missing piece is direct inspection of the original or copy plates for that field to exclude copying or scanning artifacts; the Yang & Villarroel work only confirms that the triple is not confined to a single copy plate. The strongest opposing consideration is thus that all evidence still flows through the same digitization lineage, leaving room for a plate or copy artifact explanation.

The triple is reported in a peer-reviewed MNRAS paper with 2023 10.4-m follow-up to magnitude 25.5, independently recovered (three of three) by Hayes, and reported present on a Harvard copy plate and in the original survey digitization. Dimming of more than ten magnitudes within about an hour is the observational content, not an interpretation. The strongest opposing consideration is that almost everything known still passes through the Palomar copy lineage and one team's characterisation, the isolated source looks like comparison stars rather than like the sharp 1950 nine, and the 1952 original negative has not been directly examined.

Peer-reviewed (MNRAS 2024) with deep modern follow-up to magnitude 25.5, independently recovered three-for-three by the Hayes pipeline (TRN-E008), and now reported present on a Harvard copy plate and in the original survey digitization (TRN-E022). Two cautions hold confidence at moderate: the characterization comes entirely from the proponent team, and the event is morphologically unlike the 1950 nine — the isolated source looks stellar — so the canonical events are not a uniform class any single mechanism can casually explain. The strongest opposing consideration is that nearly everything known about the triple passed through the same Palomar copy lineage, a limitation TRN-E022 has only partly relieved since the 1952 examination was of copy material, not the original negative.

The event is peer-reviewed with 10.4-m follow-up to magnitude 25.5 (TRN-E007), and all three sources are recovered by an independent pipeline that never consulted the VASCO lists (TRN-E008); TRN-E022 adds presence on a Harvard copy plate and in the original survey digitization. Confidence is moderate rather than high because the characterization — including the crucial "absent from the consecutive exposure within the hour" — comes from the proponent team on the same Palomar digitized lineage, and no examination of the 1952 original negative exists; presence there is inferred, not observed. The strongest opposing consideration is that the isolated member's star-like profile sits awkwardly beside the 1950 nine's sharpness, which any single-mechanism account, mundane or exotic, must absorb.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy plate with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, capping confidence.

Peer-reviewed with deep follow-up (TRN-E007), independently recovered (TRN-E008), and present on a Harvard copy with co-presence in the original digitization (TRN-E022). The 1952 original negative remains uninspected, capping confidence.

Peer-reviewed (MNRAS 2024) with modern 10.4-m follow-up, and the three detections are independently recovered by the Hayes pipeline. Unlike the 1950 nine, however, no published physical inspection of the surviving plate material exists, and the report comes entirely from the proponent team.

Peer-reviewed analysis documents three ~16th magnitude point sources separated by less than 10 arcseconds appearing on a single POSS-I exposure from 19 July 1952, absent from consecutive exposures taken 50 minutes later and deep follow-up imaging down to magnitude 25.5. The triple detection has also been recovered by independent automated source extraction pipelines. The strongest opposing consideration is that the original telescope negative has not yet been physically inspected under a microscope to evaluate whether the features represent optical exposures or emulsion defects.

The event is peer-reviewed with deep modern follow-up (TRN-E007: absent within the hour, GTC imaging to magnitude 25.5), independently recovered (TRN-E008, 3 of 3), and found on a Harvard copy plate and in the original survey digitization (TRN-E022). Strongest opposing consideration: no physical inspection of the 1952 original negative exists, and the event's stellar-like profiles are morphologically inconsistent with the sharper-than-stellar 1950 nine, so any single-mechanism explanation remains incomplete.

TRN-E007 reports the three closely spaced sources, their disappearance within the hour, and deep subsequent non-detections, while TRN-E008 independently recovers all three. TRN-E022 further reports corresponding features on examined copy material. The strongest opposing consideration is that the original 1952 telescope negative was not physically examined, so the observation remains somewhat more dependent on the photographic lineage than the April event.

Solano et al. document three ~16 mag sources within 10 arcsec on one 19 July 1952 exposure, absent within the hour and in 71 years of deeper imaging to mag 25.5; Hayes recovers all three; Yang reports the candidate on a Harvard copy and in the original survey digitization. Direct original-negative microscopy for 1952 is not yet published. Strongest opposing consideration: profiles of the triple are star-like rather than systematically sharp, so the two canonical events are morphologically non-uniform.

Peer-reviewed discovery report with deep modern follow-up to r ≈ 25.5 (TRN-E007), independently recovered 3/3 by Hayes's pipeline (TRN-E008), and reported present both on a Harvard copy plate and in the original survey digitization (TRN-E022). The vanishing-within-the-hour element rests on two consecutive exposures from the same night, which is thin but direct. The opposing consideration is that no examination of this event's original negative has been performed — presence there is inferred from co-presence in the original digitization, not observed — so the provenance is one step weaker than for the 1950 nine.

TRN-E007 (peer-reviewed report with 2023 GTC follow-up to magnitude 25.5), TRN-E008 (independent pipeline recovers three of three), TRN-E022 (present on a Harvard copy plate and in the original survey digitization). TRN-E018 qualifies by extending the aligned-event line without addressing provenance. No physical inspection of that event's original negative exists.

TRN-E007 (moderate; discovery with deep follow-up), TRN-E008 (strong; three of three recovered independently), TRN-E022 (present on copy plate and original digitization). TRN-E018 qualifies weakly by extending the alignment line.

The July 1952 triple transient was documented in peer-reviewed literature, recovered completely by an independent source-extraction pipeline, and confirmed absent in consecutive exposures taken less than an hour later as well as in modern GTC imaging down to magnitude 25.5. Unlike the 1950 event, the images exhibit point-spread functions consistent with regular comparison stars. Strongest opposing consideration: The plate material has not yet undergone independent, blinded physical microscopy to exclude rare microscopic emulsion anomalies or chemical deposits.

TRN-E007 is a peer-reviewed MNRAS report with deep (25.5 mag) GTC follow-up showing >10 mag dimming within an hour, and TRN-E008 recovers all three sources independently; TRN-E022 finds co-presence on copy material and the original survey digitization. The strongest opposing consideration: no physical inspection of the 1952 original negative exists (only a Harvard copy plate), and the event's star-like profiles are morphologically inconsistent with the sharper 1950 nine, so the canonical events lack the uniformity a single mechanism would predict.

TRN-E007 reports three closely spaced approximately 16th-magnitude sources on one 1952 exposure, absent from the consecutive exposure and from deep later imaging. TRN-E008 independently recovers all three with a separate pipeline, and TRN-E022 reports their presence on physical copy material. The strongest opposing consideration is that the original 1952 telescope negative has not itself been microscopically inspected, leaving the physical generation at which those marks arose less secure than for 1950.

The triple appears on one 1952 exposure, is absent from the consecutive exposure within the hour, and remains absent to magnitude 25.5 in modern imaging (E007); microscopy confirms presence on examined material (E022). Strongest opposing consideration is the lack of published physical inspection of the 1952 original negative itself, only copy and digitization.

A peer-reviewed report documents the triple, with GTC follow-up to magnitude 25.5 (E007). An independent pipeline recovers all three (E008), and the triple appears on a Harvard copy (E022). As an observation of the survey record, the claim stands. Strongest opposing consideration: nothing places the triple above the copy stage, because the original was not seen (E022). Its presence on both a copy and a copy-negative scan (E005) is what a flaw on the shared positive would produce. That bears on origin, not on this observation.

TRN-E007 (peer reviewed) reports the triple on one exposure, absent from the next within the hour and from 2023 imaging to magnitude 25.5. TRN-E008 recovers all three independently. TRN-E022 finds the triple on a Harvard copy plate and in the original digitization. Confidence is moderate because the 1952 original negative itself has not been examined.