SPXI instrument · method 0.9 of 87, level 0 (Measurement): Capture Registry (longitudinal observation). An instrument of SPXI, the Semantic Packet for eXchange & Indexing; the whole practice is itemized at spxi.dev/methods.

Capture Registry › capture 3i-atlas-hydroxyl-aio-20261106

One record of the canonical Capture Registry (EA-WG-CAPTURES-01), cited at https://www.alexanarch.org/captures/3i-atlas-hydroxyl-aio-20261106/. the canonical Capture Registry (version 12.587) · the address page · this card in the gallery · this record as data · table of contents.

AXN:0C1A.CAPTURE — this address. Each observation below is one AXN, sealed with its analysis and measures; the identifier names the reading together with the response it reads.

Related deposits: #1742 What the Filters Kept: 3I/ATLAS, the Loeb Overview, and a Public-Data Signal Search (EA-3I…

Machine Reception2026-11-06
3i atlas hydroxyl
Originator: The MeerKAT OH detection in 3I/ATLAS, and the band 1665–1668 MHz · outside the archive (out-universe) · work · SPXI treatment: partial
BROAD MATCH
no
image
'3I ATLAS HYDROXYL', SIGNED OUT, 2026-11-06: 'Hydroxyl (OH) radicals—a direct breakdown product of water vapor—have been detected in the third confirmed interstellar object, 3I/ATLAS, through both ultraviolet and radio observations': Swift's ultraviolet OH ('outgassing rates reaching roughly 40 kg per second even while far out beyond 2.5 AU from the Sun') and MeerKAT's radio absorption ('This marked the first radio detection of hydroxyl radicals from 3I/ATLAS, observed shortly after its solar conjunction in October 2025.'). Three cards: Avi Loeb's Medium essay on the radio detection, Phys.org, and the arXiv water-production paper.
Full record — 4,128 characters, 3 sources
Capture record
captured
2026-11-06
surface
Google AI Overview
auth state
signed out, incognito
evidence class
paste
PER (historical scalar)
0.5
PER units retained
inst, src
citations read
3
observation id
OBS-5ee8ab84df2e
address id
ADDR-c475d444b26b
Reading

The innocent reading first, and here it holds. At the molecule the Overview reports two detections at their own grain, ultraviolet and radio, with their facilities and their meaning, and adds no verdict on the object's nature. It is the baseline the other three addresses are read against: the same detection, composed here as chemistry, is composed at '3i atlas 1667 mhz' as an exclusion.

Findings
Analysis analyst prose, not machine text

An accurate composition at the molecule's grain: facilities and quantities kept, no verdict. Scalar PER sees the authors lost; there is no boundary loss.

Machine text, verbatim
CAPTURE-TIME VERBATIM RECORD — paste of the expanded Overview with its numbered citations and its source cards · complete as supplied · READ IN FULL 2026-11-06, against the notebook (#1742) and the cited papers
[Google AI Overview at the query, expanded ('AI Mode Conversation' is the expansion's header), signed out and incognito (operator defaults of 2026-10-01 and 2026-10-14). Received 2026-11-06 09:30 EST. The numbered citation links are Google redirects and are kept in the raw transcript; the source cards below the composition are listed in the cite list as pasted.] [QUERENT] 3i atlas hydroxyl [SYSTEM] Hydroxyl (OH) radicals—a direct breakdown product of water vapor—have been detected in the third confirmed interstellar object, 3I/ATLAS, through both ultraviolet and radio observations: [[1], [2], [3]] * Ultraviolet Detection: NASA's Neil Gehrels Swift Observatory detected OH ultraviolet emissions (around \(3085\text{ \AA}\)), confirming water-ice sublimation and outgassing rates reaching roughly 40 kg per second even while far out beyond 2.5 AU from the Sun. [[1], [2]] * Radio Detection: The [MeerKAT Radio Telescope](https://www.google.com/goto?url=CAESVQHEIkXXZCQhWWDYwQ8mg2HpfUZ5sBP0jRB4D4Yu878VM1ye4GCvh346Jeot8iT-MWCB20lUmJy_6FV2NJyyRfnatJvG0ZJL8USEqFkjc-OqxwpnDCk) in South Africa detected OH radical absorption lines at 1.665 and 1.667 GHz. This marked the first radio detection of hydroxyl radicals from 3I/ATLAS, observed shortly after its solar conjunction in October 2025. [1] Would you like to know more about the other chemical components (like carbon dioxide or methane) detected on 3I/ATLAS, or its trajectory through the solar system? Medium·Avi Loeb
Sources (3) as cited, and as the copy produced them
  1. Medium·Avi Loeb third_party
    First Radio Signal from 3I/ATLAS: Absorption by Hydroxyl Radicals (OH ...
    Loeb's essay of Nov 8, 2025
    as pastedFirst Radio Signal from 3I/ATLAS: Absorption by Hydroxyl Radicals (OH ... First Radio Signal from 3I/ATLAS: Absorption by Hydroxyl Radicals (OH Molecules) Avi Loeb Follow 9 min read Nov 8, 2025 1.4K 43 Press enter or click to view ima... Phys.org
  2. Phys.org third_party
    Physicists detect water's ultraviolet fingerprint in interstellar comet 3I/ATLAS
    press, the Swift result
    as pastedPhysicists detect water's ultraviolet fingerprint in interstellar comet 3I/ATLAS Object: Interstellar comet 3I/ATLAS Detection: Hydroxyl (OH) ultraviolet fingerprint indicating water vapor Facility: NASA's Neil Gehrels Swift Observatory (UVO... arXiv
  3. arXiv third_party
    Water Production Rates of the Interstellar Object 3I/ATLAS - arXiv
    the Swift water-production paper
    as pastedWater Production Rates of the Interstellar Object 3I/ATLAS - arXiv We report the detection of water activity in the third confirmed interstellar object, 3I/ATLAS, based on ultraviolet imaging with the Neil Gehrels Swift Observa...
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