A 2821 Star Optical SETI Survey using ESO HARPS archival data

Benjamin Fields; Jason C. Goodman

REVIEW 3 major objections 3 minor 17 references

A 2821 Star Optical SETI Survey using ESO HARPS archival data

T0 review · 3 major / 3 minor · reviewed 2026-08-15 · deepseek-v4-flash

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Pith's one-line read Analyzing 2,821 archived HARPS spectra, this paper finds three narrow-band optical lines that survive all tested false-positive categories—including cosmic rays, airglow, LiDAR interference, and adaptive-optics lasers—and warrant…

desk verdict The submitted full text is an unrelated wireless-networking paper, so the HARPS optical SETI analysis in the abstract cannot be checked; the abstract's pipeline is plausible but the candidate counts do not add up as written. read the letter →

arxiv 2508.08628 v1 pith:X2UUVBVK submitted 2025-08-12 astro-ph.IM astro-ph.SR

Benjamin Fields , Jason C. Goodman This is my paper · ORCID

classification astro-ph.IMastro-ph.SR

keywords opticalSETIHARPSarchivalspectroscopynarrow-bandlaserfalse-positiverejectionsame-nightcomparisonextraterrestrialintelligencespectrallines

verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper reports an archival search for narrow-band, laser-like emissions in spectra of 2,821 stars observed with the HARPS spectrograph. From one observation per star, it found 285 spectral peaks, then winnowed these to eight follow-up sources using false-positive removal. Analyzing 1,835 additional observations of those targets, the authors found no candidate that repeated at the same wavelength over time and identified one candidate as a likely faint airglow line. Four more candidates were later matched to identical spikes in other stars observed on the same night, indicating an unknown terrestrial source. Three candidates remain unexplained by all tested prosaic categories and are flagged as deserving further investigation.

What carries the argument

The central target signature is a narrow spectral line with a width slightly larger than HARPS's point-spread function, the expected appearance of an unresolved laser-like emission. The decisive filtering mechanism is the same-night comparison: if the same spectral spike appears in other stars observed on the same night, in the telescope's reference frame, it is assigned a terrestrial or instrumental origin. This comparison, applied on top of cosmic-ray, airglow, LiDAR, and adaptive-optics laser rejection, is what reduces seven lingering candidates to three.

What would settle it

Take the three candidate stars and observe them with another high-resolution echelle spectrograph at a different observatory. If the same narrow line appears at the same wavelength in data from a different telescope, a target-related stellar or extraterrestrial origin is supported; if it does not appear, or appears only under certain pointing or detector conditions, the candidates likely are instrumental or terrestrial artifacts that escaped the same-night test.

Watch

Extended reading notes

Core claim

Using one HARPS observation per star, the authors identified spectral peaks with line widths slightly larger than the instrument's point-spread function, a signature a laser-like extraterrestrial beacon would produce. After removing cosmic rays, instrumental artifacts, and airglow, eight sources warranted follow-up; no candidate spike repeated at the same wavelength in later observations, and one candidate was identified as faint airglow. Seven candidates defied all tested false-positive categories, including LiDAR satellite interference and adaptive-optics lasers from nearby observatories, but four of these showed identical spikes in other stars observed on the same night, pointing to a terrestrial source. This leaves three final candidates—two toward M-type stars and one toward an oscillating red giant—that show no indication of terrestrial origin and warrant further investigation. The paper does not claim detection of extraterrestrial intelligence; it claims these three candidates cannot be dismissed with the prosaic explanations examined so far.

Load-bearing premise

The filtering assumption is that a spectral spike caused by something on Earth or in the telescope will appear in other stars observed on the same night, so a spike seen in only one star's spectrum is treated as coming from that star.

Editorial extensions

If this is right

If the central claim is right, three narrow-band line candidates in HARPS archival spectra are not explained by cosmic rays, instrumental artifacts, airglow, LiDAR satellites, or adaptive-optics lasers from nearby observatories.
No initial candidate reappeared at the same wavelength in any of the 1,835 follow-up observations, so any extraterrestrial source would have to be intermittent, variable, or shifted in frequency on the timescales sampled.
The host-star distribution—two M-type stars and one oscillating red giant—means future work must separate natural stellar line emission from a possible artificial beacon.
The survey establishes a reusable archival method: one observation per star for discovery, then all archival reobservations plus same-night comparison stars for false-positive control.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

If the three candidates are real beacons, their non-repetition across archival epochs suggests they might be transient or frequency-drifting; a dedicated monitoring campaign with repeated visits and broad wavelength coverage could test that directly.
The same-night comparison assumes artifacts are not target-specific; a pointing- or detector-dependent artifact could masquerade as a candidate, so observing the same targets with a different spectrograph is a natural next test.
Compiling a catalog of intrinsic narrow emission lines in M dwarfs and oscillating red giants would let future surveys subtract stellar physics before flagging SETI candidates.

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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Desk Editor's Note

read the letter

Two things you should know up front. First, the full text on arXiv is not the paper the abstract describes; it is Conghao Zhou et al.'s wireless networking paper on mobile AR rendering. There is no HARPS data, no pipeline, no candidate list. That is a submission-integrity problem, and it means the scientific claim is currently unverifiable. Second, the abstract itself describes a reasonable optical SETI survey: 2,821 archived HARPS spectra searched for narrow spectral lines, with a sensible progression of false-positive checks, including a same-night comparison against other stars. That same-night comparison is the most genuinely useful idea in the abstract: a spike that appears in the telescope reference frame in other stars observed that night is very likely terrestrial, and using archival data to run that control is a legitimate methodological contribution.

The soft spots are real but secondary to the mismatch. The candidate counts in the abstract do not reconcile: 8 initial targets plus 1 follow-up candidate gives 9, then one airglow identification should leave 8, but the text says 7 remaining, then 4 shared, then 3 final. Probably a typo, but with no full text it is just ambiguity. The deeper technical concern is that the same-night test only catches artifacts that reproduce in other stars. Target-specific or time-dependent effects—detector state, pointing-dependent fringing, a passing satellite—would evade it. The abstract gives no wavelengths, no matched observations, no line-width threshold. So the three surviving candidates are not yet backed by any reviewable evidence. That does not mean they are wrong; it means the paper as submitted is unsupported.

What is new here is the same-night comparison control and the survey scale, not the basic technique. But this manuscript cannot be refereed. My recommendation: desk reject with a note to the authors that the wrong full text was uploaded. If the actual HARPS analysis is resubmitted, it would deserve a serious referee—the approach is sound, and the same-night null test is a contribution even if the three candidates later turn out to be mundane. As it stands, I would not cite it and would not bring it to reading group except as a cautionary example.

Referee Report

3 major / 3 minor

Summary. The submitted manuscript carries an abstract describing an optical SETI survey of 2,821 stars observed with the ESO HARPS spectrograph. According to the abstract, the search pipeline found 285 narrow spectral peaks, reduced these to 8 initial follow-up targets, found 1 additional candidate in the full set of 1,835 follow-up observations, identified 4 of the remaining candidates as sharing identical spectral spikes with other stars observed on the same night, and concluded that 3 narrow-band candidates currently defy prosaic explanations and warrant further investigation. However, the supplied full text is not this paper at all: it is an unrelated manuscript on QoE-aware service provisioning for mobile augmented reality rendering (Zhou et al.). No HARPS data, detection algorithm, candidate table, false-positive vetting procedure, or same-night comparison analysis is present in the submission. The abstract's claims therefore cannot be checked against any reviewable artifact.

Significance. If the claimed result were supported, this would be a relevant empirical contribution to optical SETI and stellar astrophysics: a systematic archival search of 2,821 stars with a high-resolution spectrograph, yielding three narrow-band candidates that survive the listed false-positive categories, with two M-type host stars and one oscillating red giant. Such a result would provide concrete follow-up targets and would be falsifiable by future observations. The strength would lie in the reproducibility of the pipeline and the completeness of the false-positive analysis. As submitted, none of those strengths are evident, because the body text is a different paper; the significance cannot be assessed beyond the abstract.

major comments (3)

[Full text (mismatch)] The full text supplied for arXiv:2508.08628 is not the manuscript described by its abstract. It is an unrelated paper, 'QoE-Aware Service Provision for Mobile AR Rendering: An Agent-Driven Approach,' and contains no HARPS spectra, no spectral-peak detection algorithm, no line-width threshold, no candidate list, no airglow or LiDAR/adaptive-optics vetting, and no description of the same-night comparison against other stars. The central claim of the abstract—that three candidates survive all tested false-positive categories—is consequently unsupported by any reviewable content. This is a load-bearing defect that a revision cannot fix; the intended manuscript must be resubmitted.
[Abstract (candidate accounting)] The abstract's candidate arithmetic is not internally consistent. It reports 8 initial follow-up targets, then states that follow-up analysis found 1 additional unexplained candidate, giving 9 candidates. It then says one candidate was identified as a likely faint airglow line, which should leave 8 candidates, yet the next sentence refers to 'the remaining seven candidates.' From 8 initial plus 1 additional minus 1 airglow, the number 7 cannot be derived unless one of the initial targets was separately removed, the additional candidate was also the airglow line, or the numbering refers to a different subset. The final count of 3 (seven minus four shared with other stars) depends on this unresolved accounting and needs a candidate-by-candidate table to be verifiable.
[Abstract (same-night comparison assumption)] The abstract's key filter is the statement that four of seven candidates showed identical spectral spikes in observations of other stars on the same night, 'indicating an as-yet unknown terrestrial source.' This assumes that a terrestrial or instrumental origin would manifest as the same spectral feature in other stars observed on the same night. As stated, the same-night comparison has no quantitative details: no wavelength tolerance, no line-width matching criterion, no signal-to-noise threshold, and no indication of how many other stars per night were compared. If the artifact is target-specific, time-dependent within the night, or dependent on pointing, detector state, or wavelength, the same-night comparison would not catch it. The conclusion that the remaining three candidates 'show no indication of a terrestrial origin' therefore requires the actual comparative spectra and matching criteria, which are not provided.

minor comments (3)

[Abstract] The sentence 'After eliminating false positives (including cosmic rays, instrumental artifacts, and terrestrial airglow lines, we identified 8 sources' has an unmatched opening parenthesis; a closing parenthesis is missing before 'we identified.'
[Abstract] The abstract says the detected peaks have 'line widths slightly larger than the instrument's point-spread function' but gives no quantitative threshold or range; a table with peak wavelengths, widths, and signal-to-noise ratios would make the search reproducible.
[Abstract] The term 'M-Type stars' is nonstandard; if these are M dwarfs, the paper should state the spectral subtype explicitly and explain why narrow-band emission is unexpected for these stars, since this is relevant to the 'oscillating red giant' host as well.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity found: the abstract reports an empirical filtering pipeline, and no load-bearing step reduces to its own inputs.

full rationale

The only reviewable content is the abstract, since the full text at the given identifier is an unrelated mobile augmented reality paper. On the abstract alone, the derivation chain is an empirical search-and-filter process: 285 spectral peaks are identified, false-positive categories are applied, follow-up observations are checked for recurrence, airglow and shared same-night spikes are removed, and three candidates remain. There is no fitted parameter that is later renamed a prediction, no quantity is defined in terms of the target result, and no cited uniqueness theorem or prior author result is invoked to force the conclusion. The same-night other-star comparison is an assumption about how terrestrial artifacts would behave, and it may be technically limited or inadequately described, but a questionable assumption is not circular reasoning: the candidates are not selected because they match the assumed artifact signature. The three final candidates are residual survivors of the cuts, so their existence is not equivalent to any input of the pipeline. The full-text mismatch is a serious completeness, reproducibility, and verification problem, but it does not provide the specific equation-level or definition-level reduction required to establish circularity. Accordingly, the appropriate circularity score is 0.

Assumptions & free parameters 1 free parameters · 3 assumptions · 0 invented entities

Only the abstract is available for audit. The main unstated inputs are the detection threshold and the completeness of the false-positive taxonomy; no new physical entities are introduced. The full text mismatch prevents a deeper audit.

free parameters (1)

Spectral peak detection threshold
The abstract reports 285 peaks with line widths 'slightly larger' than the instrument's point-spread function but does not state the threshold or algorithm parameters; the candidate count depends on this unstated cut.

assumptions (3)

domain assumption A narrow spectral line with width slightly larger than the HARPS point-spread function is a viable technosignature signature.
This is the physical premise of the search, implicit in the abstract's line-width selection criterion.
ad hoc to paper The set of tested false-positive categories is sufficiently complete to classify a candidate as non-terrestrial.
The abstract claims candidates 'defy the prosaic explanations examined thus far'; this only supports a non-terrestrial origin if the examined categories exhaust the realistic artifacts.
domain assumption Sparse sampling, one observation per star plus follow-up observations, would catch a repeating or persistent narrow-band emission.
The follow-up logic depends on recurrence being observable in the available HARPS observations.

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Cite this review

Pith. "Pith review of A 2821 Star Optical SETI Survey using ESO HARPS archival data." pith.science (2026). https://pith.science/paper/X2UUVBVK

@misc{pith2026250808628,
  author       = {Pith},
  title        = {Pith review of: A 2821 Star Optical SETI Survey using ESO HARPS archival data},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/X2UUVBVK}},
  note         = {Machine review of arXiv:2508.08628}
}

read the original abstract

We examined archived observations of 2,821 stars taken by the high-resolution ESO HARPS spectrograph to search for potential narrow-band laser emissions from extraterrestrial sources. From one observation of each star, our search algorithm identified a total of 285 spectral peaks with line widths slightly larger than the instrument's point-spread function. After eliminating false positives (including cosmic rays, instrumental artifacts, and terrestrial airglow lines, we identified 8 sources worthy of follow-up observations. We then analyzed all 1,835 additional observations of these follow-up targets, looking for recurring signals. We found 1 additional unexplained candidate in this followup search, but no candidate spikes which repeated at the same wavelength as one of the initial candidates at a later time. Further analysis identified one candidate as a likely faint airglow line. The remaining seven candidates continued to defy all false positive categories, including interference by LiDAR satellites and adaptive optics lasers from neighboring observatories. However, observations of other stars on the same night showed identical spectral spikes (in the telescope's reference frame) for four of these seven candidates -- indicating an as-yet unknown terrestrial source. This leaves 3 final candidates which currently defy the prosaic explanations examined thus far, show no indication of a terrestrial origin and therefore warrant further investigation. Two of these three candidates originate from M-Type stars and one of them originates from an oscillating red giant, so follow-up work will need to disentangle natural astrophysical stellar processes from potential SETI sources.

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Reference graph

Works this paper leans on

17 extracted references · 17 canonical work pages

[1]

User- centric immersive communications in 6G: A data-oriented framework via digital twin,

C. Zhou, S. Hu, J. Gao, X. Huang, W. Zhuang, and X. Shen, “User- centric immersive communications in 6G: A data-oriented framework via digital twin,” IEEE Wireless Commun., vol. 32, no. 3, pp. 122–129, 2025

work page 2025
[2]

AdaptSLAM: Edge-assisted adaptive SLAM with resource constraints via uncertainty minimization,

Y . Chen, H. Inaltekin, and M. Gorlatova, “AdaptSLAM: Edge-assisted adaptive SLAM with resource constraints via uncertainty minimization,” in Proc. IEEE INFOCOM , 2023, New York, NY , USA

work page 2023
[3]

Resource allocation with edge computing in iot networks via machine learning,

X. Liu, J. Yu, J. Wang, and Y . Gao, “Resource allocation with edge computing in iot networks via machine learning,” IEEE IoT J. , vol. 7, no. 4, pp. 3415–3426, 2020

work page 2020
[4]

Exploring the 6g potentials: Immersive, hyperreliable, and low-latency communication,

A. A. Shamsabadi, A. Yadav, Y . Gadallah, and H. Yanikomeroglu, “Exploring the 6g potentials: Immersive, hyperreliable, and low-latency communication,” IEEE Veh. Technol. Mag., 2025

work page 2025
[5]

Linowes and K

J. Linowes and K. Babilinski, Augmented reality for developers: Build practical augmented reality applications with Unity, ARCore, ARKit, and Vuforia. Packt Publishing Ltd, 2017

work page 2017
[6]

Digital twin-based 3D map management for edge-assisted device pose tracking in mobile AR,

C. Zhou, J. Gao, M. Li, N. Cheng, X. Shen, and W. Zhuang, “Digital twin-based 3D map management for edge-assisted device pose tracking in mobile AR,” IEEE IoT J. , vol. 11, no. 10, pp. 17 812–17 826, 2024

work page 2024
[7]

Characterizing and scheduling of diffusion process for text-to-image generation in edge networks,

S. Gao, P. Yang, Y . Kong, F. Lyu, and N. Zhang, “Characterizing and scheduling of diffusion process for text-to-image generation in edge networks,” IEEE Trans. Mobile Comput. , 2025

work page 2025
[8]

LEAD: Large-scale edge cache deployment based on spatio-temporal WiFi traffic statistics,

F. Lyu, J. Ren, N. Cheng, P. Yang, M. Li, Y . Zhang, and X. Shen, “LEAD: Large-scale edge cache deployment based on spatio-temporal WiFi traffic statistics,” IEEE Trans. Mobile Comput. , vol. 20, no. 8, pp. 2607–2623, 2020

work page 2020

Show all 17 references

[9]

Quality of experience oriented cross-layer optimization for real-time XR video transmission,

G. Pan, S. Xu, S. Zhang, X. Chen, and Y . Sun, “Quality of experience oriented cross-layer optimization for real-time XR video transmission,” IEEE Trans. Circuits Syst. Video Technol., vol. 34, no. 8, pp. 7742–7755, 2024

2024
[10]

QoE fairness resource allocation in digital twin-enabled wireless virtual reality systems,

J. Feng, L. Liu, X. Hou, Q. Pei, and C. Wu, “QoE fairness resource allocation in digital twin-enabled wireless virtual reality systems,” IEEE J. Sel. Areas Commun. , vol. 41, no. 11, pp. 3355–3368, 2023

2023
[11]

QoE-oriented communication service provision for annotation rendering in mobile augmented reality,

L. Sun, C. Zhou, S. Hu, Y . Zhu, N. Cheng, and X. Xia, “QoE-oriented communication service provision for annotation rendering in mobile augmented reality,” arXiv preprint arXiv:2501.07127 , 2025

2025 arXiv
[12]

Cross-domain based data sharing scheme in cooperative edge computing,

K. Fan, Q. Pan, J. Wang, T. Liu, H. Li, and Y . Yang, “Cross-domain based data sharing scheme in cooperative edge computing,” in Proc. IEEE EDGE, 2018, San Francisco, CA, USA

2018
[13]

Large language models (LLMs) inference offloading and resource allocation in cloud-edge computing: An active inference approach,

Y . He, J. Fang, F. R. Yu, and V . C. Leung, “Large language models (LLMs) inference offloading and resource allocation in cloud-edge computing: An active inference approach,”IEEE Trans. Mobile Comput., vol. 23, no. 12, pp. 11 253–11 264, 2024

2024
[14]

ORB-SLAM3: An accurate open-source library for visual, visual–inertial, and multimap SLAM,

C. Campos, R. Elvira, J. J. G. Rodríguez, J. M. Montiel, and J. D. Tardós, “ORB-SLAM3: An accurate open-source library for visual, visual–inertial, and multimap SLAM,” IEEE Trans. Robot. , vol. 37, no. 6, pp. 1874–1890, 2021

2021
[15]

Vivo: Visibility-aware mobile volumetric video streaming,

B. Han, Y . Liu, and F. Qian, “Vivo: Visibility-aware mobile volumetric video streaming,” in Proc. ACM MobiCom, 2020, New York, NY , USA

2020
[16]

From one thousand pages of specification to unveiling hidden bugs: Large language model assisted fuzzing of matter IoT devices,

X. Ma, L. Luo, and Q. Zeng, “From one thousand pages of specification to unveiling hidden bugs: Large language model assisted fuzzing of matter IoT devices,” in Proc. USENIX Security, 2024, Philadelphia, PA, USA

2024
[17]

NetLLM: Adapting large language models for networking,

D. Wu, X. Wang, Y . Qiao, Z. Wang, J. Jiang, S. Cui, and F. Wang, “NetLLM: Adapting large language models for networking,” in Proc. ACM SIGCOMM, 2024, New York, NY , USA

2024

Pith tools

Reviewed August 15, 2026 · model on record in the stance chip above.

[1] [1]

User- centric immersive communications in 6G: A data-oriented framework via digital twin,

C. Zhou, S. Hu, J. Gao, X. Huang, W. Zhuang, and X. Shen, “User- centric immersive communications in 6G: A data-oriented framework via digital twin,” IEEE Wireless Commun., vol. 32, no. 3, pp. 122–129, 2025

work page 2025

[2] [2]

AdaptSLAM: Edge-assisted adaptive SLAM with resource constraints via uncertainty minimization,

Y . Chen, H. Inaltekin, and M. Gorlatova, “AdaptSLAM: Edge-assisted adaptive SLAM with resource constraints via uncertainty minimization,” in Proc. IEEE INFOCOM , 2023, New York, NY , USA

work page 2023

[3] [3]

Resource allocation with edge computing in iot networks via machine learning,

X. Liu, J. Yu, J. Wang, and Y . Gao, “Resource allocation with edge computing in iot networks via machine learning,” IEEE IoT J. , vol. 7, no. 4, pp. 3415–3426, 2020

work page 2020

[4] [4]

Exploring the 6g potentials: Immersive, hyperreliable, and low-latency communication,

A. A. Shamsabadi, A. Yadav, Y . Gadallah, and H. Yanikomeroglu, “Exploring the 6g potentials: Immersive, hyperreliable, and low-latency communication,” IEEE Veh. Technol. Mag., 2025

work page 2025

[5] [5]

Linowes and K

J. Linowes and K. Babilinski, Augmented reality for developers: Build practical augmented reality applications with Unity, ARCore, ARKit, and Vuforia. Packt Publishing Ltd, 2017

work page 2017

[6] [6]

Digital twin-based 3D map management for edge-assisted device pose tracking in mobile AR,

C. Zhou, J. Gao, M. Li, N. Cheng, X. Shen, and W. Zhuang, “Digital twin-based 3D map management for edge-assisted device pose tracking in mobile AR,” IEEE IoT J. , vol. 11, no. 10, pp. 17 812–17 826, 2024

work page 2024

[7] [7]

Characterizing and scheduling of diffusion process for text-to-image generation in edge networks,

S. Gao, P. Yang, Y . Kong, F. Lyu, and N. Zhang, “Characterizing and scheduling of diffusion process for text-to-image generation in edge networks,” IEEE Trans. Mobile Comput. , 2025

work page 2025

[8] [8]

LEAD: Large-scale edge cache deployment based on spatio-temporal WiFi traffic statistics,

F. Lyu, J. Ren, N. Cheng, P. Yang, M. Li, Y . Zhang, and X. Shen, “LEAD: Large-scale edge cache deployment based on spatio-temporal WiFi traffic statistics,” IEEE Trans. Mobile Comput. , vol. 20, no. 8, pp. 2607–2623, 2020

work page 2020