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The third interstellar object ever found kept a constant red color through two months of mounting gas and dust activity, and its spectrum is redder and turns over at red wavelengths compared with the two earlier interstellar objects.

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2026-08-03 17:31 UTC pith:NBN4A5MR

load-bearing objection A solid, honest characterization paper: the earliest blue spectrum and a dense two-month time series are real new data, and the stable-color claim is plausible but rests on excluding an unexplained two-night excursion. the 3 major comments →

arxiv 2512.09020 v2 pith:NBN4A5MR submitted 2025-12-09 astro-ph.EP astro-ph.GA

University of Hawaii 88-inch Telescope Observations of the Interstellar Comet 3I/ATLAS: Spectrophotometric Blue-Sensitive Spectral Time Series Spanning Two Months from Discovery

W. B. Hoogendam , D. Kuesters , B. J. Shappee , G. Aldering , J. J. Wray , B. Yang , K. J. Meech , M. A. Tucker
show 17 more authors
M. E. Huber K. Auchettl C. R. Angus D. D. Desai J. T. Hinkle J. Kiyokawa G. S. H. Paek S. Romagnoli J. Shi A. Syncatto C. Ashall M. Dixon K. Hart A. M. Hoffman D. O. Jones K. Medler C. Pfeffer
This is my paper
classification astro-ph.EP astro-ph.GA
keywords interstellar object3I/ATLAScometary activityspectral slopereflectance spectroscopyCN emissionsynthetic photometryintegral field spectrograph
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

This paper argues that 3I/ATLAS, the third interstellar object discovered, maintained a nearly constant red optical color during its two-month pre-perihelion approach, even as its gas emission and dust production ramped up sharply. Using nine integral-field spectra from July to September 2025, the authors find red spectral slopes of 20 to 29 percent per thousand angstroms in the blue-optical range and stable synthetic colors in the g-r, r-i, and c-o bands. The significance is that the continuum color of this object appears to be decoupled from its cometary activity, meaning the visible color is set by a steady dust population rather than by the volatile release that drives the brightening. If correct, this gives a direct constraint on the surface and dust properties of an object from another planetary system, and it makes 3I/ATLAS redder than the two previously known interstellar objects.

Core claim

3I/ATLAS exhibits a red reflectance color throughout its spectral evolution, with spectral slopes of roughly 20 to 29 percent per 1000 angstroms across 4000 to 7000 angstroms and mostly stable colors (g-r around 0.69 to 0.75 mag, r-i 0.26 to 0.30 mag, c-o 0.50 to 0.55 mag) over the entire two-month time series. This stability persists despite clear increases in CN, nickel, and dust activity, including the first detection of CN in these data on August 18. The redder-wavelength slopes are flatter, showing a turnover at red wavelengths that the paper argues is atypical for comets and slightly redder than the D-type asteroid class. The paper concludes that 3I/ATLAS is generally redder than 1I/'O

What carries the argument

The central tool is integral-field spectrophotometry with a blue-sensitive spectrograph (covering 3400 to 10000 angstroms), which provides spatially resolved, flux-calibrated spectra. The team divides each target spectrum by a solar-analogue star spectrum to obtain reflectance spectra normalized at 5500 angstroms, then measures spectral slopes through linear fits with bootstrap uncertainties. Synthetic photometry through Pan-STARRS griz and ATLAS co filters converts the spectra into colors, and a simple Haser model converts CN line fluxes into production rates. The IFU design is load-bearing because it enables reliable flux calibration and clean extraction of the comet's point-source-like si

Load-bearing premise

The claim of mostly stable color evolution depends on treating the July 12 and 14 spectra, which show a distinct red-slope spike, as data artifacts or intrinsic scatter rather than real physical changes, and the paper explicitly states it cannot identify the cause of the July 12 anomaly.

What would settle it

A single independent, well-calibrated spectrum of 3I/ATLAS taken on July 12 or 14, or a re-reduction of the original IFU data cubes using a different extraction or response-correction model, that reproduces the steep red slope would falsify the mostly-stable color claim; if the anomaly disappears under reprocessing, the stable-color interpretation is confirmed.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • If the continuum color is truly decoupled from gas activity, then optical colors of distant active comets track dust properties, not volatile release, so color changes should not be used as a direct proxy for activity level.
  • The turnover at red wavelengths implies that broadband blue-optical colors alone can misrepresent the object's surface or grain composition; multi-wavelength coverage is needed to characterize interstellar objects.
  • All three known interstellar objects show red colors, suggesting reddening may be a common outcome of interstellar processing; 3I/ATLAS being redder could indicate a longer or more intense space-weathering history.
  • The measured CN production rates, rising from an upper limit in July to about 3 x 10^24 molecules per second in September, provide a baseline for comparing volatile release in interstellar versus solar-system comets.
  • The proposed two-phase evolution (a pre-discovery reddening phase followed by a stable red phase) offers a way to reconcile conflicting early color reports and predicts that post-perihelion colors will remain red unless the dust regime changes.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If the July 12-14 spectral-slope spike is real rather than an artifact, it would mark a short-lived dust-grain event, possibly the sublimation of icy grains the authors mention; independent spectra on those exact nights would settle whether the stable-color narrative holds.
  • A testable extension is that as 3I/ATLAS recedes post-perihelion and dust production decays, the continuum color should remain constant until the steady-state dust population breaks down; continued monitoring could directly test the dust-coupling claim.
  • The paper's treatment of the July 3 spectrum, where a stellar streak contaminated red wavelengths but the blue channel remained usable, suggests that blue-only spectra from otherwise contaminated IFU exposures can still yield reliable science, a methodological point useful for future fast-moving comet observations.
  • The flattening at red wavelengths, if confirmed by near-infrared data, would point toward a specific grain-size distribution or composition, and could be compared with laboratory spectra of irradiated organic materials to infer the object's interstellar residence time.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 5 minor

Summary. This paper presents nine epochs of SNIFS/UH 2.2m integral-field spectrophotometry of 3I/ATLAS obtained between 2025 July 3 and September 2, covering roughly 3200–10000 Å with the blue channel reaching the CN/Ni region. The data are flux-calibrated through the established SCAT/SNIFS pipeline, divided by solar analogues to form reflectance spectra, and used for synthetic photometry, spectral-slope measurements, and Haser-model CN production rates. The authors report that 3I/ATLAS had a red continuum with 4000–7000 Å slopes of about 20–29%/1000 Å and mostly stable colors (g−r≈0.69–0.75, r−i≈0.26–0.30, c−o≈0.50–0.55 mag) during the two-month window, despite the onset of CN, Ni, and dust activity. They argue that 3I/ATLAS is redder than 1I/‘Oumuamua and 2I/Borisov and that its reflectance turns over toward flatter slopes at redder wavelengths. The paper is transparent that the July 12 and 14 epochs are anomalous, with the July 12 issue unresolved.

Significance. If the conclusions hold, this is a valuable homogeneous, blue-sensitive time series of the third interstellar object, including the earliest λ≤3800 Å spectrum and independent confirmation of CN and Ni activity. The paper makes good use of an established reduction pipeline, external solar analogues, and literature g-factors, and it tabulates slopes and colors in a way that facilitates comparison with the many other 3I/ATLAS papers. The robust parts—a red dust-dominated continuum and a red-wavelength flattening—are consistent with independent measurements. The weaker part is the quantitative claim of color stability, which depends on excluding two anomalous epochs without a demonstrated cause and on an unquantified systematic error budget. Thus the central qualitative picture is credible, but the headline stability claim needs strengthening before publication.

major comments (3)
  1. [§4 and §5.2, with Tables 2 and 4] The 'mostly stable color evolution' claim explicitly excludes the July 12–14 epochs, but the paper does not establish that those epochs are artifacts. Section 4 states that the July 12 blue slope 'may likely be erroneous' but that the authors are 'unable to find the exact cause,' and Table 4 shows a 3900–5500 Å slope of 39.1±0.8%/1000 Å with an alternative solar analogue giving ~17%/1000 Å. Since the exclusion is not tied to a demonstrated data-quality failure, the central stability conclusion rests on an unresolved judgment. Moreover, the colors in Table 2 for July 12 (g−r=0.74, r−i=0.29, c−o=0.54) and July 14 (g−r=0.74, r−i=0.30, c−o=0.55) are within the quoted stable ranges, so the text's statement that these spectra 'have different colors' is internally inconsistent. Please either identify the artifact, include these epochs in a quantitative stability test, or explicitly present the
  2. [§3.3 and Table 4; §2 solar analogues] The central quantitative claims—a 20–29%/1000 Å slope range and color ranges only ~0.05–0.06 mag wide—are quoted with only statistical uncertainties (0.01 mag, bootstrap errors), with no systematic error budget. This matters because the same solar analogue was not actually used for all epochs: §2 states that HD 142801 was used on September 2 and adjacent-night analogues for July 3 and 19, contrary to §3's statement that 'we use the same solar analogue for all our observations.' Differences among solar analogues, the PSF-model extraction aperture, and the dichroic crossover can plausibly shift slopes and colors at the level of the claimed stability. Please quantify these systematics (e.g., using all available analogues, varying the continuum mask, and testing the extraction aperture) and state a conservative uncertainty on the stability claim.
  3. [§3.3, spectral-slope definition] The definition of the reported spectral slope is under-specified. The reflectance is normalized at 5500 Å, but the paper does not state whether the %/1000 Å values are evaluated at 5500 Å, at the center of each fitted range, or as (ΔR/R_mean)/Δλ. This ambiguity directly affects the 'redder slopes are flatter' turnover claim: a linearly rising absolute reflectance automatically yields lower percentage gradients when evaluated at redder wavelengths. Please provide the exact formula and confirm that the 6500–9000 Å flattening in Table 4 and Figure 5 persists when the same convention is applied to all wavelength ranges (or when log-reflectance slopes are used).
minor comments (5)
  1. [§3] The sentence 'Because we use the same solar analogue for all our observations...' is contradicted by §2, where HD 142801 is used for the final epoch and adjacent-night analogues for July 3 and 19. Please rephrase to state which epochs share which analogue.
  2. [§3.2 and Table 3] The CN production rates differ by roughly a factor of two between the 2″ and 3″ aperture assumptions. Please state the assumed Haser scale lengths, g-factor, and outflow speed explicitly in the text, and avoid presenting the 3″ values as definitive without an aperture uncertainty.
  3. [Figure 5 and Table 4] It is not immediately clear from Figure 5 whether the July 12–14 points are plotted. Please mark them explicitly and add a caption note describing their status, so the reader can connect Figure 5 with the discussion in §4.
  4. [Abstract and §5.2] The abstract quotes slopes of 0–29%/1000 Å while §5.2 quotes 20–29%/1000 Å. These are both defensible if the wavelength range is stated, but the paper should consistently specify the range (e.g., 4000–7000 Å for 20–29%, and the full range for 0–29%).
  5. [§5.2] The text gives the last epoch as September 2, 2025 at 'r≈2.0 au,' but Table 1 lists r_h=2.47 au. This appears to be a typo and should be corrected.

Circularity Check

0 steps flagged

No circularity: spectrophotometric measurements calibrated against external solar analogues and literature g-factors; self-citation only for independent aperture check.

full rationale

This is an observational spectrophotometric study. The central claims (red reflectance, stable g-r/r-i/c-o colors, CN production rates) are measured directly from SNIFS spectra divided by solar-analogue spectra and calibrated with external g-factors and Haser scale lengths from A'Hearn et al. (1995) and Biver et al. (1999). No fitted parameter is renamed as a prediction: the spectral slopes are linear fits to the reflectance spectra, and the synthetic photometry is computed from flux-calibrated spectra rather than from a model that assumes stable colors. The only invocation of the authors' own prior work is the choice of a 3'' aperture for CN production rates, justified by the coma extent seen in independent KCWI data (Hoogendam et al. 2025a); this is not circular because it is an independent observation, and the paper reports both 2'' and 3'' rates to bracket the systematic. The explicit July 12-14 exclusion from the 'mostly stable' color claim (Section 4 and Section 5.2) is an unresolved data-quality judgment and a correctness risk, not a circularity: the paper admits it cannot identify the cause, but the remaining epochs are compared with external measurements from other groups. No derivation step reduces to its own input by construction.

Axiom & Free-Parameter Ledger

3 free parameters · 5 axioms · 0 invented entities

The paper is observational and introduces no new entities. The central numbers depend on standard calibration and modeling assumptions: solar-analogue representation, Haser-model parameters, expansion-velocity scaling, PSF extraction, and a hand-set aperture. The continuum polynomial and normalization are fitted nuisance parameters, not physics.

free parameters (3)
  • Continuum polynomial coefficients b1, b2 (Eq. 1) = per-epoch fitted values, not tabulated
    Used in the continuum model F_cont(lambda) = R(lambda) * F_solar(...) for continuum subtraction before measuring emission-line fluxes. The fitted slope coefficients affect the CN and Ni line flux estimates.
  • Continuum normalization S (Eq. 1) = per-epoch fitted values, not tabulated
    Normalizes the solar-analogue flux to the comet flux in the continuum model; affects the absolute line-to-continuum ratio.
  • Aperture radius for Q(CN) computation = 2 arcsec and 3 arcsec assumed
    The PSF extraction has an unknown effective aperture, so production rates are reported assuming 2- and 3-arcsecond radii; the 3-arcsecond values are preferred, but this choice is hand-set, not measured.
axioms (5)
  • domain assumption Haser model validity: gas escapes isotropically at constant velocity and A'Hearn (1995) scale lengths apply to 3I/ATLAS
    Used to convert CN line flux into Q(CN). If the coma geometry or parent/daughter scale lengths differ for this interstellar comet, the production rates scale accordingly.
  • domain assumption Expansion speed relation v = 0.8 * r_h^-0.6 km/s (Biver et al. 1999)
    Adopted from prior comet literature and used in the Haser-model scale-length conversion; not independently measured for 3I/ATLAS.
  • domain assumption Solar-analogue stars represent the solar spectrum for reflectance division
    Reflectance spectra and colors are computed as comet divided by solar analogue. The paper notes that the July 12 secondary analogue HD 157842 and HD 165290 differ significantly, so solar-analogue mismatch is a real systematic risk.
  • domain assumption SNIFS flux calibration from the SN Factory pipeline is accurate
    Synthetic photometry and reflectance slopes depend on the absolute flux calibration described by Buton et al. (2013) and the SNIFS reduction pipeline; the paper does not provide independent validation.
  • domain assumption PSF-model extraction captures essentially all coma flux
    The paper states that some coma may be lost to the sky but is negligible because the flux profile is nucleus-dominated. This assumption affects both colors and production-rate aperture corrections.

pith-pipeline@v1.3.0-alltime-deepseek · 21014 in / 11592 out tokens · 120630 ms · 2026-08-03T17:31:35.410410+00:00 · methodology

0 comments
read the original abstract

Interstellar objects are the ejected building blocks of other solar systems. As such, they enable the acquisition of otherwise inaccessible information about nascent extrasolar systems. The discovery of the third interstellar object, 3I/ATLAS, provides an opportunity to explore the properties of a small body from another solar system and to compare it to the small bodies in our own. To that end, we present spectrophotometric observations of 3I/ATLAS taken using the SuperNova Integral Field Spectrograph on the University of Hawaii 2.2-m telescope. Our data includes the earliest $\lambda\leq3800$ A spectrum of 3I/ATLAS, obtained $\sim$12.5 hours after the discovery announcement. Later spectra confirm previously reported cometary activity, including Ni and CN emission. The data show wavelength-varying spectral slopes ($S\approx($0\%-29\%)/1000 A, depending on wavelength range) throughout the pre-perihelion ($r_h=4.4$-$2.5$ au) approach of 3I/ATLAS. We perform synthetic photometry on our spectra and find 3I/ATLAS shows mostly stable color evolution over the period of our observations, with $g-r$ colors ranging from $\sim$0.69-0.75 mag, $r-i$ colors ranging from $\sim$0.26-0.30 mag, and $c-o$ colors ranging from $\sim$0.50-0.55 mag. Ongoing post-perihelion observations of 3I/ATLAS will provide further insight into its potentially extreme composition.

Figures

Figures reproduced from arXiv: 2512.09020 by A. M. Hoffman, A. Syncatto, B. J. Shappee, B. Yang, C. Ashall, C. Pfeffer, C. R. Angus, D. D. Desai, D. Kuesters, D. O. Jones, G. Aldering, G. S. H. Paek, J. J. Wray, J. Kiyokawa, J. Shi, J. T. Hinkle, K. Auchettl, K. Hart, K. J. Meech, K. Medler, M. A. Tucker, M. Dixon, M. E. Huber, S. Romagnoli, W. B. Hoogendam.

Figure 1
Figure 1. Figure 1: — The spectrophotometric time series data of 3I/ATLAS from the UH 2.2-meter telescope taken with the SNIFS spectrograph. Grey [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: — Synthetic photometry in the Pan-STARRS [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: — The continuum-subtracted spectra showing emission lines from Ni (dotted red), Fe (dashed green), and CN (solid blue). [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: — The spectral slope evolution fits for several epochs of [PITH_FULL_IMAGE:figures/full_fig_p006_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: — The spectral slope evolution for 3I/ATLAS from our [PITH_FULL_IMAGE:figures/full_fig_p006_5.png] view at source ↗

discussion (0)

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Forward citations

Cited by 6 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Near-perihelion activity and composition of 3I/ATLAS from JUICE/MAJIS observations

    astro-ph.EP 2026-07 conditional novelty 6.0

    Near-perihelion observations of interstellar comet 3I/ATLAS with JUICE/MAJIS reveal CO2-driven activity, a ~10% CO2/H2O ratio, and tentative evidence for complex organic material in coma dust.

  2. SCAT Data Release 1: 1810 optical spectra of 1330 transients

    astro-ph.HE 2026-04 accept novelty 6.0

    SCAT DR1 delivers 1810 spectra of 1330 transients with classifications, fitted light curves, new redshifts for many host galaxies, and host properties as a testbed for photometric classification pipelines.

  3. Post-perihelion Coma Composition of the Interstellar Comet 3I/ATLAS from Optical Spectroscopy

    astro-ph.EP 2026-03 unverdicted novelty 6.0

    Post-perihelion optical spectroscopy of 3I/ATLAS reveals less C2 depletion than pre-perihelion, perihelion asymmetry in CN and metal production, metal release tied to CO rather than H2O, and residual [O I] emission in...

  4. Post-perihelion Coma Composition of the Interstellar Comet 3I/ATLAS from Optical Spectroscopy

    astro-ph.EP 2026-03 unverdicted novelty 6.0

    Post-perihelion spectra of 3I/ATLAS show reduced C2 depletion, asymmetric CN/metal outgassing, metal-CO correlation, and an unexplained [O I] residual after standard parent subtraction.

  5. Assessment of the Mass Loss and Radius Change of 3I/ATLAS Based on Observed Production Rates

    astro-ph.EP 2026-05 unverdicted novelty 5.0

    The paper estimates 3I/ATLAS lost 1.05-6.56 meters of surface material (0.10-1.13% of its mass, or 10^9-10^10 kg) during its solar system passage based on observed production rates.

  6. Assessment of the Mass Loss and Radius Change of 3I/ATLAS Based on Observed Production Rates

    astro-ph.EP 2026-05 conditional novelty 4.0

    3I/ATLAS lost roughly 1–7 meters of its surface and ~10^9–10^10 kg of mass during its Solar System passage, based on fits to observed gas production rates.

Reference graph

Works this paper leans on

104 extracted references · 14 canonical work pages · cited by 4 Pith papers · 2 internal anchors

  1. [1]

    Birch, P. V. 1995, Icarus, 118, 223, doi:10.1006/icar.1995.1190

    arXiv 1995

  2. [2]

    2002, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference

    Aldering, G., Adam, G., Antilogus, P., et al. 2002, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference

    2002

  3. [3]

    4836, Survey and Other Telescope Technologies and Discoveries, ed

    Series, Vol. 4836, Survey and Other Telescope Technologies and Discoveries, ed. J. A. Tyson & S. Wolff, 61–72, doi:10.1117/12.458107

    doi:10.1117/12.458107

  4. [4]

    2006, ApJ, 650, 510, doi:10.1086/507020

    Aldering, G., Antilogus, P., Bailey, S., et al. 2006, ApJ, 650, 510, doi:10.1086/507020

    doi:10.1086/507020 2006

  5. [5]

    2021, MNRAS, 502, 3491, doi:10.1093/mnras/stab084

    Aravind, K., Ganesh, S., Venkataramani, K., et al. 2021, MNRAS, 502, 3491, doi:10.1093/mnras/stab084

    doi:10.1093/mnras/stab084 2021

  6. [6]

    2001, MNRAS, 326, 23, doi:10.1046/j.1365-8711.2001.04612.x

    Bacon, R., Copin, Y., Monnet, G., et al. 2001, MNRAS, 326, 23, doi:10.1046/j.1365-8711.2001.04612.x

    arXiv 2001

  7. [7]

    2010, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference

    Bacon, R., Accardo, M., Adjali, L., et al. 2010, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference

    2010

  8. [8]

    7735, Ground-based and Airborne Instrumentation for Astronomy III, ed

    Series, Vol. 7735, Ground-based and Airborne Instrumentation for Astronomy III, ed. I. S. McLean, S. K. Ramsay, & H. Takami, 773508, doi:10.1117/12.856027

    doi:10.1117/12.856027

  9. [9]

    T., Opitom, C., Fitzsimmons, A., et al

    Bannister, M. T., Opitom, C., Fitzsimmons, A., et al. 2020, arXiv e-prints, arXiv:2001.11605. https://arxiv.org/abs/2001.11605

    Pith/arXiv arXiv 2020

  10. [10]

    2025, PASJ, doi:10.1093/pasj/psaf097

    Beniyama, J. 2025, PASJ, doi:10.1093/pasj/psaf097

    doi:10.1093/pasj/psaf097 2025

  11. [11]

    Binzel, R. P. 1992, Icarus, 99, 238, doi:10.1016/0019-1035(92)90185-A

    work page doi:10.1016/0019-1035(92)90185-a 1992

  12. [12]

    1999, AJ, 118, 1850, doi:10.1086/301033

    Biver, N., Bockel´ ee-Morvan, D., Crovisier, J., et al. 1999, AJ, 118, 1850, doi:10.1086/301033

    work page doi:10.1086/301033 1999

  13. [13]

    P., Cordiner, M

    Bodewits, D., Bonev, B. P., Cordiner, M. A., & Villanueva, G. L. 2024, in Comets III, ed. K. J. Meech, M. R. Combi, D. Bockel´ ee-Morvan, S. N. Raymodn, & M. E. Zolensky (University of Arizona Press), 407–432, doi:10.2458/azu_uapress_9780816553631-ch013

    work page doi:10.2458/azu_uapress_9780816553631-ch013 2024

  14. [14]

    W., Feldman, P

    Bodewits, D., Noonan, J. W., Feldman, P. D., et al. 2020, Nature Astronomy, 4, 867, doi:10.1038/s41550-020-1095-2

    doi:10.1038/s41550-020-1095-2 2020

  15. [15]

    T., Belyakov, M., Fremling, C., et al

    Bolin, B. T., Belyakov, M., Fremling, C., et al. 2025, MNRAS, 542, L139, doi:10.1093/mnrasl/slaf078

    doi:10.1093/mnrasl/slaf078 2025

  16. [16]

    T., Sato, H., et al

    Borisov, G., Durig, D. T., Sato, H., et al. 2019, Central Bureau Electronic Telegrams, 4666, 1

    2019

  17. [17]

    2015, in Asteroids IV, ed

    Strazzulla, G. 2015, in Asteroids IV, ed. P. Michel, F. E. DeMeo, & W. F. Bottke, 597–616, doi:10.2458/azu_uapress_9780816532131-ch031

    doi:10.2458/azu_uapress_9780816532131-ch031 2015

  18. [18]

    2013, A&A, 549, A8, doi:10.1051/0004-6361/201219834

    Buton, C., Copin, Y., Aldering, G., et al. 2013, A&A, 549, A8, doi:10.1051/0004-6361/201219834

    doi:10.1051/0004-6361/201219834 2013

  19. [19]

    C., Magnier, E

    Chambers, K. C., Magnier, E. A., Metcalfe, N., et al. 2016, arXiv e-prints, arXiv:1612.05560, doi:10.48550/arXiv.1612.05560

    Pith/arXiv arXiv doi:10.48550/arxiv.1612.05560 2016

  20. [20]

    O., Bernardinelli, P

    Chandler, C. O., Bernardinelli, P. H., Juri´ c, M., et al. 2025, arXiv e-prints, arXiv:2507.13409, doi:10.48550/arXiv.2507.13409

    Pith/arXiv arXiv doi:10.48550/arxiv.2507.13409 2025

  21. [21]

    A., Milam, S

    Cordiner, M. A., Milam, S. N., Biver, N., et al. 2020, Nature Astronomy, 4, 861, doi:10.1038/s41550-020-1087-2

    doi:10.1038/s41550-020-1087-2 2020

  22. [22]

    A., Roth, N

    Cordiner, M. A., Roth, N. X., Kelley, M. S. P., et al. 2025, arXiv e-prints, arXiv:2508.18209, doi:10.48550/arXiv.2508.18209

    Pith/arXiv arXiv doi:10.48550/arxiv.2508.18209 2025

  23. [23]

    M., Kuan, Y.-J., Charnley, S

    Coulson, I. M., Kuan, Y.-J., Charnley, S. B., et al. 2025, arXiv e-prints, arXiv:2510.02817, doi:10.48550/arXiv.2510.02817

    doi:10.48550/arxiv.2510.02817 2025

  24. [24]

    2020, ApJ, 893, L12, doi:10.3847/2041-8213/ab8455 de la Fuente Marcos, R., Alarcon, M

    Cremonese, G., Fulle, M., Cambianica, P., et al. 2020, ApJ, 893, L12, doi:10.3847/2041-8213/ab8455 de la Fuente Marcos, R., Alarcon, M. R., Licandro, J., et al. 2025, A&A, 700, L9, doi:10.1051/0004-6361/202556439 de Le´ on, J., Licandro, J., de la Fuente Marcos, C., et al. 2020, MNRAS, 495, 2053, doi:10.1093/mnras/staa1190

    doi:10.3847/2041-8213/ab8455 2020

  25. [25]

    E., Bannister, M

    Deam, S. E., Bannister, M. T., Opitom, C., et al. 2025, arXiv e-prints, arXiv:2507.05051, doi:10.48550/arXiv.2507.05051

    Pith/arXiv arXiv doi:10.48550/arxiv.2507.05051 2025

  26. [26]

    E., Binzel, R

    DeMeo, F. E., Binzel, R. P., Slivan, S. M., & Bus, S. J. 2009, Icarus, 202, 160, doi:10.1016/j.icarus.2009.02.005

    doi:10.1016/j.icarus.2009.02.005 2009

  27. [27]

    2025, MPEC

    Denneau, L., Siverd, R., Tonry, J., et al. 2025, MPEC

    2025

  28. [28]

    A., & Tonry, J

    Do, A., Tucker, M. A., & Tonry, J. 2018, ApJ, 855, L10, doi:10.3847/2041-8213/aaae67

    doi:10.3847/2041-8213/aaae67 2018

  29. [29]

    2017, AJ, 153, 133, doi:10.3847/1538-3881/aa5c8a

    Engelhardt, T., Jedicke, R., Vereˇ s, P., et al. 2017, AJ, 153, 133, doi:10.3847/1538-3881/aa5c8a

    doi:10.3847/1538-3881/aa5c8a 2017

  30. [30]

    D., Noonan, J

    Feinstein, A. D., Noonan, J. W., & Seligman, D. Z. 2025, ApJ, 991, L2, doi:10.3847/2041-8213/adfd4d

    doi:10.3847/2041-8213/adfd4d 2025

  31. [31]

    2024, in Comets III, ed

    Fitzsimmons, A., Meech, K., Matr` a, L., & Pfalzner, S. 2024, in Comets III, ed. K. J. Meech, M. R. Combi, D. Bockel´ ee-Morvan, S. N. Raymodn, & M. E. Zolensky, 731–766

    2024

  32. [32]

    2018, Nature Astronomy, 2, 133, doi:10.1038/s41550-017-0361-4

    Fitzsimmons, A., Snodgrass, C., Rozitis, B., et al. 2018, Nature Astronomy, 2, 133, doi:10.1038/s41550-017-0361-4

    doi:10.1038/s41550-017-0361-4 2018

  33. [33]

    J., et al

    Fitzsimmons, A., Hainaut, O., Meech, K. J., et al. 2019, ApJ, 885, L9, doi:10.3847/2041-8213/ab49fc For´ es-Toribio, R., JoHantgen, B., Kochanek, C. S., et al. 2025, The Open Journal of Astrophysics, 8, 114, doi:10.33232/001c.143105

    doi:10.3847/2041-8213/ab49fc 2019

  34. [34]

    T., Yaginuma, A., Noonan, J

    Frincke, T. T., Yaginuma, A., Noonan, J. W., et al. 2025, arXiv e-prints, arXiv:2509.02813, doi:10.48550/arXiv.2509.02813

    work page doi:10.48550/arxiv.2509.02813 2025

  35. [35]

    2020, ApJ, 890, 89, doi:10.3847/1538-4357/ab67b9

    Gronoff, G., Maggiolo, R., Cessateur, G., et al. 2020, ApJ, 890, 89, doi:10.3847/1538-4357/ab67b9

    doi:10.3847/1538-4357/ab67b9 2020

  36. [36]

    2020, Nature Astronomy, 4, 53, doi:10.1038/s41550-019-0931-8

    Guzik, P., Drahus, M., Rusek, K., et al. 2020, Nature Astronomy, 4, 53, doi:10.1038/s41550-019-0931-8

    doi:10.1038/s41550-019-0931-8 2020

  37. [37]

    1957, Bulletin de la Societe Royale des Sciences de Liege, 43, 740

    Haser, L. 1957, Bulletin de la Societe Royale des Sciences de Liege, 43, 740

    1957

  38. [38]

    T., Yang, B., Meech, K

    Hinkle, J. T., Yang, B., Meech, K. J., et al. 2025a, arXiv e-prints, arXiv:2512.02106.https://arxiv.org/abs/2512.02106

    Pith/arXiv arXiv

  39. [39]

    T., Holoien, T

    Hinkle, J. T., Holoien, T. W. S., Auchettl, K., et al. 2021, MNRAS, 500, 1673, doi:10.1093/mnras/staa3170

    doi:10.1093/mnras/staa3170 2021

  40. [40]

    T., Tucker, M

    Hinkle, J. T., Tucker, M. A., Shappee, B. J., et al. 2023, MNRAS, 519, 2035, doi:10.1093/mnras/stac3659

    doi:10.1093/mnras/stac3659 2023

  41. [41]

    T., Auchettl, K., Hoogendam, W

    Hinkle, J. T., Auchettl, K., Hoogendam, W. B., et al. 2024, arXiv e-prints, arXiv:2412.15326, doi:10.48550/arXiv.2412.15326

    Pith/arXiv arXiv doi:10.48550/arxiv.2412.15326 2024

  42. [42]

    T., Shappee, B

    Hinkle, J. T., Shappee, B. J., Auchettl, K., et al. 2025b, Science Advances, 11, eadt0074, doi:10.1126/sciadv.adt0074

    doi:10.1126/sciadv.adt0074

  43. [43]

    B., Hinkle, J

    Hoogendam, W. B., Hinkle, J. T., Shappee, B. J., et al. 2024, MNRAS, 530, 4501, doi:10.1093/mnras/stae1121

    doi:10.1093/mnras/stae1121 2024

  44. [44]

    B., Shappee, B

    Hoogendam, W. B., Shappee, B. J., Wray, J. J., et al. 2025a, arXiv e-prints, arXiv:2510.11779. https://arxiv.org/abs/2510.11779

    arXiv

  45. [45]

    B., Jones, D

    Hoogendam, W. B., Jones, D. O., Ashall, C., et al. 2025b, The Open Journal of Astrophysics, 8, 120, doi:10.33232/001c.143462

    doi:10.33232/001c.143462

  46. [46]

    B., Ashall, C., Jones, D

    Hoogendam, W. B., Ashall, C., Jones, D. O., et al. 2025c, ApJ, 988, 209, doi:10.3847/1538-4357/ade787

    doi:10.3847/1538-4357/ade787

  47. [47]

    J., Dorsey, R

    Hopkins, M. J., Dorsey, R. C., Forbes, J. C., et al. 2025, From a Different Star: 3I/ATLAS in the context of the ¯Otautahi-Oxford interstellar object population model. https://arxiv.org/abs/2507.05318

    Pith/arXiv arXiv 2025

  48. [48]

    Hui, M.-T., Ye, Q.-Z., F¨ ohring, D., Hung, D., & Tholen, D. J. 2020, AJ, 160, 92, doi:10.3847/1538-3881/ab9df8 Hutsem´ ekers, D., Manfroid, J., Jehin, E., et al. 2025, arXiv e-prints, arXiv:2509.26053, doi:10.48550/arXiv.2509.26053

    doi:10.48550/arxiv.2509.26053 2020

  49. [49]

    2025, ApJ, 990, L2, doi:10.3847/2041-8213/adf8d8

    Jewitt, D., Hui, M.-T., Mutchler, M., Kim, Y., & Agarwal, J. 2025, ApJ, 990, L2, doi:10.3847/2041-8213/adf8d8

    doi:10.3847/2041-8213/adf8d8 2025

  50. [50]

    2019, ApJ, 886, L29, doi:10.3847/2041-8213/ab530b —

    Jewitt, D., & Luu, J. 2019, ApJ, 886, L29, doi:10.3847/2041-8213/ab530b —. 2025, ApJ, 994, L3, doi:10.3847/2041-8213/ae1832

    doi:10.3847/2041-8213/ab530b 2019

  51. [51]

    2017, ApJL, 850, L36, doi:10.3847/2041-8213/aa9b2f

    Jewitt, D., Luu, J., Rajagopal, J., et al. 2017, ApJL, 850, L36, doi:10.3847/2041-8213/aa9b2f

    doi:10.3847/2041-8213/aa9b2f 2017

  52. [52]

    Jewitt, D., & Seligman, D. Z. 2023, ARA&A, 61, 197, doi:10.1146/annurev-astro-071221-054221

    doi:10.1146/annurev-astro-071221-054221 2023

  53. [53]

    W., Harris, W

    Kareta, T., Noonan, J. W., Harris, W. M., & Springmann, A. 2023, PSJ, 4, 85, doi:10.3847/PSJ/accc28

    doi:10.3847/psj/accc28 2023

  54. [54]

    W., et al

    Kareta, T., Andrews, J., Noonan, J. W., et al. 2020, ApJ, 889, L38, doi:10.3847/2041-8213/ab6a08

    doi:10.3847/2041-8213/ab6a08 2020

  55. [55]

    2025, arXiv e-prints, arXiv:2507.12234

    Kareta, T., Champagne, C., McClure, L., et al. 2025, arXiv e-prints, arXiv:2507.12234. https://arxiv.org/abs/2507.12234

    Pith/arXiv arXiv 2025

  56. [56]

    2020, ApJ, 895, L34, doi:10.3847/2041-8213/ab9228

    Kim, Y., Jewitt, D., Mutchler, M., et al. 2020, ApJ, 895, L34, doi:10.3847/2041-8213/ab9228

    doi:10.3847/2041-8213/ab9228 2020

  57. [57]

    King, I. R. 1983, PASP, 95, 163, doi:10.1086/131139

    doi:10.1086/131139 1983

  58. [58]

    Kolokolova, L., Kelley, M. S. P., Kimura, H., & Hoang, T. 2024, in Comets III, ed. K. J. Meech, M. R. Combi, D. Bockel´ ee-Morvan, S. N. Raymodn, & M. E. Zolensky, 621–652, doi:10.2458/azu_uapress_9780816553631-ch019

    work page doi:10.2458/azu_uapress_9780816553631-ch019 2024

  59. [59]

    2004, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference

    Lantz, B., Aldering, G., Antilogus, P., et al. 2004, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference

    2004

  60. [60]

    5249, Optical Design and Engineering, ed

    Series, Vol. 5249, Optical Design and Engineering, ed. L. Mazuray, P. J. Rogers, & R. Wartmann, 146–155, doi:10.1117/12.512493

    doi:10.1117/12.512493

  61. [61]

    S., Connelley, M

    Lee, E., Emerson, K. S., Connelley, M. S., et al. 2022, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference

    2022

  62. [62]

    12184, Ground-based and Airborne Instrumentation for Astronomy IX, ed

    Series, Vol. 12184, Ground-based and Airborne Instrumentation for Astronomy IX, ed. C. J. Evans, J. J. Bryant, & K. Motohara, 121848D, doi:10.1117/12.2627277

    work page doi:10.1117/12.2627277

  63. [63]

    2018, Space Sci

    Levasseur-Regourd, A.-C., Agarwal, J., Cottin, H., et al. 2018, Space Sci. Rev., 214, 64, doi:10.1007/s11214-018-0496-3 11

    doi:10.1007/s11214-018-0496-3 2018

  64. [64]

    W., Lee, C.-H., Gerdes, D

    Lin, H. W., Lee, C.-H., Gerdes, D. W., et al. 2020, ApJ, 889, L30, doi:10.3847/2041-8213/ab6bd9

    doi:10.3847/2041-8213/ab6bd9 2020

  65. [65]

    M., Bach, Y

    Lisse, C. M., Bach, Y. P., Bryan, S., et al. 2025, arXiv e-prints, arXiv:2508.15469, doi:10.48550/arXiv.2508.15469

    Pith/arXiv arXiv doi:10.48550/arxiv.2508.15469 2025

  66. [66]

    2025, arXiv e-prints, arXiv:2510.26308, doi:10.48550/arXiv.2510.26308

    Cessateur, G. 2025, arXiv e-prints, arXiv:2510.26308, doi:10.48550/arXiv.2510.26308

    doi:10.48550/arxiv.2510.26308 2025

  67. [67]

    2020, ApJ, 901, 136, doi:10.3847/1538-4357/abacc3

    Maggiolo, R., Gronoff, G., Cessateur, G., et al. 2020, ApJ, 901, 136, doi:10.3847/1538-4357/abacc3

    doi:10.3847/1538-4357/abacc3 2020

  68. [68]

    2025, arXiv e-prints, arXiv:2508.02499, doi:10.48550/arXiv.2508.02499 Mazzotta Epifani, E., Dotto, E., Perna, D., et al

    Martinez-Palomera, J., Tuson, A., Hedges, C., et al. 2025, arXiv e-prints, arXiv:2508.02499, doi:10.48550/arXiv.2508.02499 Mazzotta Epifani, E., Dotto, E., Perna, D., et al. 2021, Planet. Space Sci., 208, 105341, doi:10.1016/j.pss.2021.105341

    work page doi:10.48550/arxiv.2508.02499 2025

  69. [69]

    2024, in AAS/Division for Planetary Sciences Meeting Abstracts, Vol

    McKay, A., Opitom, C., Jehin, E., et al. 2024, in AAS/Division for Planetary Sciences Meeting Abstracts, Vol. 56, 56th Annual Meeting of the Division for Planetary Sciences, 301.01

    2024

  70. [70]

    J., Cochran, A

    McKay, A. J., Cochran, A. L., Dello Russo, N., & DiSanti, M. A. 2020, ApJ, 889, L10, doi:10.3847/2041-8213/ab64ed

    doi:10.3847/2041-8213/ab64ed 2020

  71. [71]

    J., Weryk, R., Micheli, M., et al

    Meech, K. J., Weryk, R., Micheli, M., et al. 2017, Nature, 552, 378, doi:10.1038/nature25020

    doi:10.1038/nature25020 2017

  72. [72]

    C., et al

    Morrissey, P., Matuszewski, M., Martin, D. C., et al. 2018, ApJ, 864, 93, doi:10.3847/1538-4357/aad597

    doi:10.3847/1538-4357/aad597 2018

  73. [73]

    Neustadt, J. M. M., Hinkle, J. T., Kochanek, C. S., et al. 2023, MNRAS, 521, 3810, doi:10.1093/mnras/stad725

    doi:10.1093/mnras/stad725 2023

  74. [74]

    2019, A&A, 631, L8, doi:10.1051/0004-6361/201936959

    Opitom, C., Fitzsimmons, A., Jehin, E., et al. 2019, A&A, 631, L8, doi:10.1051/0004-6361/201936959

    doi:10.1051/0004-6361/201936959 2019

  75. [75]

    2021, A&A, 650, L19, doi:10.1051/0004-6361/202141245

    Opitom, C., Jehin, E., Hutsem´ ekers, D., et al. 2021, A&A, 650, L19, doi:10.1051/0004-6361/202141245

    doi:10.1051/0004-6361/202141245 2021

  76. [76]

    2025, arXiv e-prints, arXiv:2507.05226, doi:10.48550/arXiv.2507.05226 ’Oumuamua ISSI Team, Bannister, M

    Opitom, C., Snodgrass, C., Jehin, E., et al. 2025, arXiv e-prints, arXiv:2507.05226, doi:10.48550/arXiv.2507.05226 ’Oumuamua ISSI Team, Bannister, M. T., Bhandare, A., et al. 2019, Nature Astronomy, 3, 594, doi:10.1038/s41550-019-0816-x

    Pith/arXiv arXiv doi:10.48550/arxiv.2507.05226 2025

  77. [77]

    2025, arXiv e-prints, arXiv:2509.03593, doi:10.48550/arXiv.2509.03593

    Pandey, P., Hinkle, J., Kochanek, C., et al. 2025, arXiv e-prints, arXiv:2509.03593, doi:10.48550/arXiv.2509.03593

    work page doi:10.48550/arxiv.2509.03593 2025

  78. [78]

    P., Popescu, M., Licandro, J., et al

    Prodan, G. P., Popescu, M., Licandro, J., et al. 2024, MNRAS, 529, 3521, doi:10.1093/mnras/stae539

    doi:10.1093/mnras/stae539 2024

  79. [79]

    Protopapa, S., Kelley, M. S. P., Yang, B., et al. 2018, ApJ, 862, L16, doi:10.3847/2041-8213/aad33b

    doi:10.3847/2041-8213/aad33b 2018

  80. [80]

    Spectral Characteristics of Interstellar Object 3I/ATLAS from SOAR Observations

    Luco, B. 2025, arXiv e-prints, arXiv:2508.02777, doi:10.48550/arXiv.2508.02777

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.2508.02777 2025

Showing first 80 references.