pith. sign in

arxiv: 2606.05344 · v1 · pith:D2KOWQWMnew · submitted 2026-06-03 · 🌌 astro-ph.EP · astro-ph.GA· astro-ph.IM

Sky-Plane Velocity Distributions of Interstellar Objects and Implications for Their Detection

Cassidy E. Walker , Darryl Z. Seligman This is my paper

Pith reviewed 2026-06-28 03:56 UTC · model grok-4.3

classification 🌌 astro-ph.EP astro-ph.GAastro-ph.IM
keywords interstellar objectssky-plane velocitydetection biassynthetic populationsanalytic motion formulavelocity distributions1I
0
0 comments X

The pith

Interstellar objects can move across the sky faster than surveys link, suggesting many dim ones remain undetected.

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

The paper develops an analytic formula for the apparent sky motion of an object on any orbit viewed from any location and applies it to three synthetic populations of roughly 100,000 interstellar objects placed inside heliocentric spheres of 1.2, 3.0, and 5.0 AU. These populations are assigned absolute-magnitude distributions appropriate for asteroids and for comets, then evaluated at a range of limiting magnitudes to produce sky-velocity distributions. The resulting distributions show that brighter objects and active comets reach detection thresholds at lower speeds than fainter objects, while the high-velocity tails extend beyond the discovery motion of 1I. This pattern implies that linking difficulties for fast-moving, intrinsically dim interstellar objects could leave a larger population undetected as it crosses the Solar System.

Core claim

The sky motions of the three known interstellar objects are typical for populations of similar absolute magnitude; brighter objects and active comets reach observable magnitudes at lower speeds than dimmer ones; and the velocity distributions possess tails extending to speeds faster than the discovery motion of 1I, indicating that detection and linking challenges may leave additional interstellar objects unobserved.

What carries the argument

Analytic solution for the apparent sky motion of an arbitrary orbit observed at an arbitrary location, applied to evaluate sky motions within three synthetic populations of interstellar objects.

If this is right

  • The sky motions of the three known interstellar objects fall within the characteristic range for populations of comparable absolute magnitude.
  • Intrinsically brighter objects reach detection magnitude thresholds at lower speeds than dimmer objects.
  • Active comets reach detection thresholds at lower speeds than asteroids for the same apparent magnitude.
  • The velocity distributions possess tails that extend to speeds faster than the discovery motion of 1I.

Where Pith is reading between the lines

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

  • Survey linking algorithms tuned only to slower motions would systematically miss the high-velocity tail of the interstellar-object population.
  • Revised population estimates that incorporate the missed fast movers would be higher than current counts based on detected objects alone.
  • The same analytic motion formula could be reused to assess detection biases for other classes of fast-moving solar-system bodies.
  • Improved cadence or software for high-speed object linking would constitute a direct test of whether the undetected fraction is large.

Load-bearing premise

The three synthetic populations of approximately 10^5 interstellar objects placed within heliocentric spheres of 1.2, 3.0, and 5.0 AU radii together with the assumed absolute-magnitude distributions for asteroids and comets are representative of the true underlying population.

What would settle it

A dedicated search either detects or fails to detect interstellar objects with sky-plane speeds substantially higher than the tails of the computed distributions at the rates those tails predict.

Figures

Figures reproduced from arXiv: 2606.05344 by Cassidy E. Walker, Darryl Z. Seligman.

Figure 1
Figure 1. Figure 1: Sky motion over time for 1I/‘Oumuamua (top) and 2I/Borisov (bottom), using JPL Horizons ephemerides data, overplotted with values from 3D calculation in Equation A2. Object Discovery Date 𝑚𝑉 Sky Motion [◦ /d] 1I 19 Oct 2017 19.705 6.6433 2I 29 Aug 2019 18.815 0.4684 3I 01 Jul 2025 18.170 0.4850 Object Fastest Date 𝑚𝑉 Max. Motion [◦ /d] 1I 15 Oct 2017 19.958 12.2088 2I 08 Dec 2019 16.663 0.8654 3I 26 Dec 20… view at source ↗
Figure 2
Figure 2. Figure 2: The apparent sky motion as a function of perihelion distance and orbital inclination. We set remaining parameters of interstellar object eccentricity, argument of periastron, and longitude of ascending node, to be 𝑒 = 1.9, 𝜔 = 3.4 rad, and Ω = 3.1 rad based on the spread of values for these elements in the synthetic population generated in section 3.1. The true anomaly values of the interstellar object and… view at source ↗
Figure 3
Figure 3. Figure 3: Apparent sky motion for given values of the true anomaly of the Earth and the interstellar object orbital inclination. We set the remaining parameters of interstellar object semimajor axis, eccentricity, true anomaly, argument of periastron, and longitude of ascending node, to be 𝑎 = −2.0 AU, 𝑒 = 1.9, 𝑓 = 0.0 rad, 𝜔 = 3.4 rad, and Ω = 3.1 rad based on the spread of values for these elements in the syntheti… view at source ↗
Figure 4
Figure 4. Figure 4: (Top row) Distributions of sky motions for asteroid-like objects, calculated using the 3D approximation in Equation A2 for 106,398 interstellar objects within a heliocentric model sphere of radius 1.2 AU when they reach apparent v-band magnitudes of 17.0, 19.0, 22.0, and 25.0. The red dotted lines mark the apparent sky motion of 1I/‘Oumuamua at discovery (6.6433 deg/day), and the black dotted lines represe… view at source ↗
Figure 5
Figure 5. Figure 5: Summary statistics showing the median, 1-sigma, and 2-sigma quartiles for distributions of sky motions shown in [PITH_FULL_IMAGE:figures/full_fig_p007_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Similar to [PITH_FULL_IMAGE:figures/full_fig_p008_6.png] view at source ↗
read the original abstract

In the past decade, three macroscopic-scale interstellar objects have been discovered, implying that a larger galactic population exists. In this paper, we investigate the possibility that the rapid sky-plane velocities of interstellar objects may preclude their discovery. We provide an analytic solution for the apparent sky motion of an object on an arbitrary orbit observed at an arbitrary location which (i) is more efficient and (ii) requires less overhead than the numerical approach. This formula is applied to evaluate the typical sky motion of an interstellar object as a function of its orbit and limiting magnitude/distance. We generate three synthetic populations of $\sim10^5$ interstellar objects within heliocentric spheres of radii 1.2, 3.0, and 5.0 AU, and calculate the sky motion for these objects when they reach a range of limiting magnitudes for multiple populations of interstellar asteroids and comets. The sky motions of the three known interstellar objects are broadly characteristic of populations with similar absolute magnitudes. Moreover, the intrinsically brighter objects reach detection magnitude thresholds at lower speeds than the dim objects, and active comets at even lower speeds for the same apparent magnitudes. The tails of these distributions extend to speeds faster than the discovery motion of 1I. Therefore, the difficulties associated with linking rapidly moving interstellar objects, especially those with intrinsically dim properties, could imply that more exist undetected traversing the Solar System.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The paper derives an analytic expression for the sky-plane angular velocity of an object on an arbitrary orbit viewed from an arbitrary location, then applies it to three synthetic populations of ~10^5 interstellar objects placed inside heliocentric spheres of radii 1.2, 3.0 and 5.0 AU. Using assumed absolute-magnitude distributions for interstellar asteroids and comets, it computes sky-motion distributions at various limiting magnitudes and concludes that the high-velocity tails exceed the discovery motion of 1I, implying that many (especially faint) ISOs remain undetected because of rapid apparent motion.

Significance. If the synthetic populations are representative, the work supplies a quantitative framework for assessing ISO detection biases and motivates targeted search strategies for high proper-motion objects. The provision of a closed-form sky-motion formula rather than a purely numerical approach is a clear methodological strength that reduces computational overhead for population studies.

major comments (2)
  1. [synthetic population generation (abstract and methods)] The central implication that high-speed tails imply many undetected ISOs rests on the representativeness of the three ~10^5-object populations placed inside fixed heliocentric spheres together with the adopted absolute-magnitude distributions. The manuscript provides no explicit description of how galactic velocity vectors, impact parameters, or hyperbolic excess speeds are sampled; if these differ from the true encounter distribution, the tails (and therefore the detection-bias conclusion) can shift without altering the analytic formula itself.
  2. [results and discussion of sky-motion distributions] No quantitative validation, error analysis, or direct comparison of the computed sky-motion distributions against the three known ISOs (beyond the qualitative statement that they are “broadly characteristic”) is presented. This leaves the strength of the claim that the tails extend beyond 1I’s discovery motion dependent on untested assumptions about the underlying orbital and magnitude distributions.
minor comments (2)
  1. [abstract] The abstract would benefit from a brief quantitative statement (e.g., fraction or percentile) of objects exceeding the sky motion of 1I at each limiting magnitude.
  2. [analytic derivation] Notation for the analytic sky-motion formula should be defined once in a dedicated subsection before its application to the populations.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their constructive review and for highlighting the utility of the analytic sky-motion formula. We address the two major comments point by point below, indicating where revisions will be made to improve clarity and strengthen the supporting evidence.

read point-by-point responses

  1. Referee: The central implication that high-speed tails imply many undetected ISOs rests on the representativeness of the three ~10^5-object populations placed inside fixed heliocentric spheres together with the adopted absolute-magnitude distributions. The manuscript provides no explicit description of how galactic velocity vectors, impact parameters, or hyperbolic excess speeds are sampled; if these differ from the true encounter distribution, the tails (and therefore the detection-bias conclusion) can shift without altering the analytic formula itself.

    Authors: We agree that the sampling procedure requires explicit documentation. In the revised manuscript we will expand the methods section to detail the sampling of galactic velocity vectors (drawn from a Maxwellian distribution consistent with local stellar kinematics), impact parameters (uniform within the heliocentric sphere), and hyperbolic excess speeds (drawn from a distribution informed by prior ISO encounter models). These choices will be justified with references to the literature. The analytic formula remains independent of the specific population model, but the added description will allow readers to evaluate how changes in the encounter distribution would affect the high-velocity tails. revision: yes

  2. Referee: No quantitative validation, error analysis, or direct comparison of the computed sky-motion distributions against the three known ISOs (beyond the qualitative statement that they are “broadly characteristic”) is presented. This leaves the strength of the claim that the tails extend beyond 1I’s discovery motion dependent on untested assumptions about the underlying orbital and magnitude distributions.

    Authors: We acknowledge the absence of quantitative validation. In revision we will add a new figure and accompanying text that directly compares the sky-motion distributions for synthetic objects with absolute magnitudes matching those of the three known ISOs against their reported discovery motions, including median and percentile statistics. We will also include a brief sensitivity analysis showing how the high-velocity tail changes with modest variations in the adopted magnitude distributions. A full statistical error analysis is limited by the small number of known objects, but the added quantitative metrics will better support the claim that the tails exceed 1I’s motion. revision: partial

Circularity Check

0 steps flagged

Analytic sky-motion formula is independent of synthetic population inputs

full rationale

The paper derives an analytic expression for sky-plane motion of an arbitrary orbit observed at an arbitrary location from first principles; this formula is then applied to three synthetic populations of ~10^5 objects placed in fixed heliocentric spheres together with separately assumed absolute-magnitude distributions. No equation reduces to a self-definition, no fitted parameter is relabeled as a prediction, and no load-bearing premise rests on a self-citation chain. The central claim about high-speed tails follows directly from applying the independent formula to the external synthetic inputs, making the derivation self-contained.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Based solely on the abstract, no explicit free parameters, axioms, or invented entities are identified.

pith-pipeline@v0.9.1-grok · 5786 in / 1052 out tokens · 26800 ms · 2026-06-28T03:56:55.117343+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

129 extracted references · 108 canonical work pages · 24 internal anchors

  1. [1]

    MPEC , year = 2025, month = jul, number =

    3I/ATLAS = C/2025 N1 (ATLAS). MPEC , year = 2025, month = jul, number =

    2025

  2. [2]

    , keywords =

    Discovery and Preliminary Characterization of a Third Interstellar Object: 3I/ATLAS. , keywords =. doi:10.3847/2041-8213/adf49a , archivePrefix =. 2507.02757 , primaryClass =

    work page doi:10.3847/2041-8213/adf49a 2041

  3. [3]

    Central Bureau Electronic Telegrams , year = 2017, month = oct, volume =

    Minor Planets 2017 SN\_33 and 2017 U1. Central Bureau Electronic Telegrams , year = 2017, month = oct, volume =

    2017

  4. [4]

    Central Bureau Electronic Telegrams , year = "2019", month = sep, volume =

    Comet C/2019 Q4 (Borisov). Central Bureau Electronic Telegrams , year = "2019", month = sep, volume =

    2019

  5. [5]

    , year = 2017, month = dec, volume =

    A brief visit from a red and extremely elongated interstellar asteroid. Nature , year = 2017, month = dec, volume = 552, pages =. doi:10.1038/nature25020 , adsurl =

    work page doi:10.1038/nature25020 2017

  6. [6]

    , archivePrefix = "arXiv", eprint =

    1I/2017 U1 (`Oumuamua) is Hot: Imaging, Spectroscopy, and Search of Meteor Activity. , archivePrefix = "arXiv", eprint =. doi:10.3847/2041-8213/aa9a34 , adsurl =

    work page doi:10.3847/2041-8213/aa9a34 2017

  7. [7]

    The Astrophysical Journal Letters , abstract =

    Interstellar Interloper 1I/2017 U1: Observations from the NOT and WIYN Telescopes. ApJL , archivePrefix = "arXiv", eprint =. doi:10.3847/2041-8213/aa9b2f , adsurl =

    work page doi:10.3847/2041-8213/aa9b2f 2017

  8. [8]

    , volume=

    Spitzer observations of interstellar object 1I/‘Oumuamua , author=. , volume=. 2018 , publisher=

    2018

  9. [9]

    , keywords =

    Initial Characterization of Interstellar Comet 2I/2019 Q4 (Borisov). , keywords =. 2019. doi:10.3847/2041-8213/ab530b , archivePrefix =. 1910.02547 , primaryClass =

    work page doi:10.3847/2041-8213/ab530b 2019

  10. [10]

    Outburst and Splitting of Interstellar Comet 2I/Borisov , volume=

    Jewitt, David and Kim, Yoonyoung and Mutchler, Max and Weaver, Harold and Agarwal, Jessica and Hui, Man-To , year=. Outburst and Splitting of Interstellar Comet 2I/Borisov , volume=. The Astrophysical Journal Letters , publisher=. doi:10.3847/2041-8213/ab99cb , number=

    work page doi:10.3847/2041-8213/ab99cb 2041

  11. [11]

    , keywords =

    Masses of long-period comets derived from non-gravitational effects - analysis of the computed results and the consistency and reliability of the non-gravitational parameters. , keywords =. doi:10.1111/j.1365-2966.2011.19111.x , adsurl =

    work page doi:10.1111/j.1365-2966.2011.19111.x 2011

  12. [12]

    , year = 2010, month = oct, volume =

    A three-parameter magnitude phase function for asteroids. , year = 2010, month = oct, volume =. doi:10.1016/j.icarus.2010.04.003 , adsurl =

    work page doi:10.1016/j.icarus.2010.04.003 2010

  13. [13]

    , keywords =

    Detection of CN Gas in Interstellar Object 2I/Borisov. , keywords =. doi:10.3847/2041-8213/ab49fc , archivePrefix =. 1909.12144 , primaryClass =

    work page doi:10.3847/2041-8213/ab49fc 2041

  14. [14]

    , keywords =

    Pre-discovery Activity of New Interstellar Comet 2I/Borisov beyond 5 au. , keywords =. doi:10.3847/1538-3881/ab659b , archivePrefix =. 1911.05902 , primaryClass =

    work page doi:10.3847/1538-3881/ab659b 1911

  15. [15]

    and Chang, Chin-Shin and Hainaut, Olivier R

    Yang, Bin and Li, Aigen and Cordiner, Martin A. and Chang, Chin-Shin and Hainaut, Olivier R. and Williams, Jonathan P. and Meech, Karen J. and Keane, Jacqueline V. and Villard, Eric , Da =. Nature Astronomy , Title =. 2021 , Bdsk-Url-1 =. doi:10.1038/s41550-021-01336-w , Id =

    work page doi:10.1038/s41550-021-01336-w 2021

  16. [16]

    , keywords =

    Coma Anisotropy and the Rotation Pole of Interstellar Comet 2I/Borisov. , keywords =. doi:10.3847/2041-8213/ab9228 , archivePrefix =. 2005.02468 , primaryClass =

    work page doi:10.3847/2041-8213/ab9228 2041

  17. [17]

    , keywords =

    Detection of a Water Tracer in Interstellar Comet 2I/Borisov. , keywords =. doi:10.3847/2041-8213/ab64ed , archivePrefix =. 1910.12785 , primaryClass =

    work page doi:10.3847/2041-8213/ab64ed 2041

  18. [18]

    Nature Astronomy , keywords =

    Initial characterization of interstellar comet 2I/Borisov. Nature Astronomy , keywords =. 2020. doi:10.1038/s41550-019-0931-8 , archivePrefix =. 1909.05851 , primaryClass =

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

  19. [19]

    , keywords =

    Physical Characterization of Interstellar Comet 2I/2019 Q4 (Borisov). , keywords =. doi:10.3847/1538-3881/ab9df8 , adsurl =

    work page doi:10.3847/1538-3881/ab9df8 2019

  20. [20]

    , keywords =

    Dust Environment Model of the Interstellar Comet 2I/Borisov. , keywords =. doi:10.3847/2041-8213/ab8455 , adsurl =

    work page doi:10.3847/2041-8213/ab8455 2041

  21. [21]

    Synthetic population of interstellar objects in the Solar System , journal =

    Dušan Marčeta , keywords =. Synthetic population of interstellar objects in the Solar System , journal =. 2023 , issn =. doi:https://doi.org/10.1016/j.ascom.2023.100690 , url =

    work page doi:10.1016/j.ascom.2023.100690 2023

  22. [22]

    Dynamical Evolution of the Early Solar System

    Dynamical Evolution of the Early Solar System. , keywords =. doi:10.1146/annurev-astro-081817-052028 , archivePrefix =. 1807.06647 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1146/annurev-astro-081817-052028

  23. [23]

    2005", month =

    Origin of the orbital architecture of the giant planets of the Solar System. , year = "2005", month = "May", volume =. doi:10.1038/nature03539 , adsurl =

    work page doi:10.1038/nature03539 2005

  24. [24]

    Origin of the Structure of the Kuiper Belt during a Dynamical Instability in the Orbits of Uranus and Neptune

    Origin of the structure of the Kuiper belt during a dynamical instability in the orbits of Uranus and Neptune. Icarus , keywords =. 2008. doi:10.1016/j.icarus.2007.11.035 , archivePrefix =. 0712.0553 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1016/j.icarus.2007.11.035 2008

  25. [25]

    Orbital Evolution of Planets Embedded in a Planetesimal Disk

    Orbital Evolution of Planets Embedded in a Planetesimal Disk. , keywords =. doi:10.1086/300891 , archivePrefix =. astro-ph/9902370 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1086/300891

  26. [26]

    , year = 2004, month = aug, volume =

    Planetary migration in a planetesimal disk: why did Neptune stop at 30 AU?. , year = 2004, month = aug, volume =. doi:10.1016/j.icarus.2004.03.011 , adsurl =

    work page doi:10.1016/j.icarus.2004.03.011 2004

  27. [27]

    , year = 2005, month = may, volume =

    Chaotic capture of Jupiter's Trojan asteroids in the early Solar System. , year = 2005, month = may, volume =. doi:10.1038/nature03540 , adsurl =

    work page doi:10.1038/nature03540 2005

  28. [28]

    , archivePrefix = "arXiv", eprint =

    Will the Large Synoptic Survey Telescope Detect Extra-Solar Planetesimals Entering the Solar System?. , archivePrefix = "arXiv", eprint =. doi:10.1088/0004-637X/704/1/733 , adsurl =

    work page doi:10.1088/0004-637x/704/1/733

  29. [29]

    , keywords =

    A Probability of Encounter with Interstellar Comets and the Likelihood of their Existence. , keywords =. doi:10.1016/0019-1035(76)90189-5 , adsurl =

    work page doi:10.1016/0019-1035(76)90189-5

  30. [30]

    , keywords =

    On the Nondetection of Extrasolar Comets. , keywords =. doi:10.1086/185590 , adsurl =

    work page doi:10.1086/185590

  31. [31]

    , keywords =

    On the missing interstellar comets. , keywords =

  32. [32]

    Earth Moon and Planets , year = 2003, month = jun, volume =

    Project Pan-STARRS and the Outer Solar System. Earth Moon and Planets , year = 2003, month = jun, volume =. doi:10.1023/B:MOON.0000031961.88202.60 , adsurl =

    work page doi:10.1023/b:moon.0000031961.88202.60 2003

  33. [33]

    An Observational Upper Limit on the Interstellar Number Density of Asteroids and Comets

    An Observational Upper Limit on the Interstellar Number Density of Asteroids and Comets. AJ , keywords =. 2017. doi:10.3847/1538-3881/aa5c8a , archivePrefix =. 1702.02237 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/1538-3881/aa5c8a 2017

  34. [34]

    ApJ , archivePrefix = "arXiv", eprint =

    Realistic Detectability of Close Interstellar Comets. ApJ , archivePrefix = "arXiv", eprint =. doi:10.3847/0004-637X/825/1/51 , adsurl =

    work page doi:10.3847/0004-637x/825/1/51

  35. [35]

    arXiv e-prints , archivePrefix = "arXiv", eprint =

    The Pan-STARRS1 Surveys. arXiv e-prints , archivePrefix = "arXiv", eprint =

  36. [36]

    Implications for planetary system formation from interstellar object 1I/2017 U1 (`Oumuamua)

    Implications for Planetary System Formation from Interstellar Object 1I/2017 U1 ( Oumuamua). , keywords =. 2017. doi:10.3847/2041-8213/aa9989 , archivePrefix =. 1711.01344 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/2041-8213/aa9989 2017

  37. [37]

    Research Notes of the American Astronomical Society , archivePrefix = "arXiv", eprint =

    On the Consequences of the Detection of an Interstellar Asteroid. Research Notes of the American Astronomical Society , archivePrefix = "arXiv", eprint =. doi:10.3847/2515-5172/aaa02b , adsurl =

    work page doi:10.3847/2515-5172/aaa02b

  38. [38]

    A., & Tonry, J

    Interstellar Interlopers: Number Density and Origin of Oumuamua-like Objects. ApJL , archivePrefix = "arXiv", eprint =. doi:10.3847/2041-8213/aaae67 , adsurl =

    work page doi:10.3847/2041-8213/aaae67 2041

  39. [39]

    Origin of 1I/ Oumuamua. I. An Ejected Protoplanetary Disk Object?. , keywords =. doi:10.3847/1538-4357/aadf34 , archivePrefix =. 1810.02148 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/1538-4357/aadf34

  40. [40]

    Origin of 1I/ Oumuamua. II. An Ejected Exo-Oort Cloud Object?. , keywords =. doi:10.3847/1538-3881/aafda6 , archivePrefix =. 1811.00023 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/1538-3881/aafda6

  41. [41]

    , keywords =

    Precovery Observations of 3I/ATLAS from TESS Suggest Possible Distant Activity. , keywords =. doi:10.3847/2041-8213/adfd4d , archivePrefix =. 2507.21967 , primaryClass =

    work page doi:10.3847/2041-8213/adfd4d 2041

  42. [42]

    arXiv e-prints , keywords =

    Nucleus and Postperihelion Activity of Interstellar Object 3I/ATLAS Observed by Hubble Space Telescope. arXiv e-prints , keywords =. doi:10.48550/arXiv.2601.21569 , archivePrefix =. 2601.21569 , primaryClass =

    work page doi:10.48550/arxiv.2601.21569

  43. [43]

    , keywords =

    The Population of Interstellar Objects Detectable with the LSST and Accessible for In Situ Rendezvous with Various Mission Designs. , keywords =. doi:10.3847/PSJ/ac58fe , archivePrefix =. 2109.10406 , primaryClass =

    work page doi:10.3847/psj/ac58fe

  44. [44]

    , keywords =

    The Visibility of the \= O tautahi─Oxford Interstellar Object Population Model in LSST. , keywords =. doi:10.3847/PSJ/adf8ca , archivePrefix =. 2502.16741 , primaryClass =

    work page doi:10.3847/psj/adf8ca

  45. [45]

    , year = 2018, month = jun, volume =

    Non-gravitational acceleration in the trajectory of 1I/2017 U1 ('Oumuamua). , year = 2018, month = jun, volume =. doi:10.1038/s41586-018-0254-4 , adsurl =

    work page doi:10.1038/s41586-018-0254-4 2017

  46. [46]

    ATLAS: A High-Cadence All-Sky Survey System

    ATLAS: A High-cadence All-sky Survey System. , keywords =. doi:10.1088/1538-3873/aabadf , archivePrefix =. 1802.00879 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1088/1538-3873/aabadf

  47. [47]

    The ATLAS All-Sky Stellar Reference Catalog

    The ATLAS All-Sky Stellar Reference Catalog. , keywords =. doi:10.3847/1538-4357/aae386 , archivePrefix =. 1809.09157 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/1538-4357/aae386

  48. [48]

    , volume=

    Could 1I/’Oumuamua be an Icy Fractal Aggregate? , author=. , volume=. 2019 , publisher=

    2019

  49. [49]

    , keywords =

    The Interstellar Object Oumuamua as a Fractal Dust Aggregate. , keywords =. doi:10.3847/2041-8213/ab4f78 , archivePrefix =. 1910.07135 , primaryClass =

    work page doi:10.3847/2041-8213/ab4f78 2041

  50. [50]

    , keywords =

    'Oumuamua as a Cometary Fractal Aggregate: The ``Dust Bunny'' Model. , keywords =. doi:10.3847/2041-8213/abafa7 , archivePrefix =. 2008.10083 , primaryClass =

    work page doi:10.3847/2041-8213/abafa7 2041

  51. [51]

    Could Solar Radiation Pressure Explain 'Oumuamua's Peculiar Acceleration?

    Could Solar Radiation Pressure Explain Oumuamua s Peculiar Acceleration?. , keywords =. doi:10.3847/2041-8213/aaeda8 , archivePrefix =. 1810.11490 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.3847/2041-8213/aaeda8 2041

  52. [52]

    Size and Compositional Constraints , author=

    1I/‘Oumuamua as an N2 ice fragment of an exo-Pluto surface: I. Size and Compositional Constraints , author=. Journal of Geophysical Research: Planets , pages=. 2021 , publisher=

    2021

  53. [53]

    Journal of Geophysical Research: Planets , pages=

    1I/‘Oumuamua as an N2 ice fragment of an exo-pluto surface II: Generation of N2 ice fragments and the origin of ‘Oumuamua , author=. Journal of Geophysical Research: Planets , pages=. 2021 , publisher=

    2021

  54. [54]

    Astrobiology , year = 2022, month = dec, volume =

    Some Pertinent Issues for Interstellar Panspermia Raised after the Discovery of 1I/`Oumuamua. Astrobiology , year = 2022, month = dec, volume =. doi:10.1089/ast.2021.0199 , adsurl =

    work page doi:10.1089/ast.2021.0199 2022

  55. [55]

    arXiv e-prints , keywords =

    Outgassing As Trigger of 1I/`Oumuamua's Nongravitational Acceleration: Could This Hypothesis Work at All?. arXiv e-prints , keywords =

  56. [56]

    , keywords =

    Evidence that 1I/2017 U1 ('Oumuamua) was Composed of Molecular Hydrogen Ice. , keywords =. doi:10.3847/2041-8213/ab963f , archivePrefix =. 2005.12932 , primaryClass =

    work page doi:10.3847/2041-8213/ab963f 2017

  57. [57]

    Solid H2 in the interstellar medium

    Solid H _ 2 in the interstellar medium. , keywords =. doi:10.1051/0004-6361/201731739 , archivePrefix =. 1712.01160 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1051/0004-6361/201731739

  58. [58]

    , keywords =

    Assessing the Formation of Solid Hydrogen Objects in Starless Molecular Cloud Cores. , keywords =. doi:10.3847/1538-4357/abec85 , archivePrefix =. 2103.05449 , primaryClass =

    work page doi:10.3847/1538-4357/abec85

  59. [59]

    , keywords =

    Acceleration of 1I/`Oumuamua from radiolytically produced H _ 2 in H _ 2 O ice. , keywords =. doi:10.1038/s41586-022-05687-w , archivePrefix =. 2303.13698 , primaryClass =

    work page doi:10.1038/s41586-022-05687-w

  60. [60]

    , keywords =

    Constraints on the Occurrence of 'Oumuamua-Like Objects. , keywords =. doi:10.3847/1538-4357/ac1fe6 , archivePrefix =. 2108.11194 , primaryClass =

    work page doi:10.3847/1538-4357/ac1fe6

  61. [61]

    Two Distinct Populations of Dark Comets Delineated by Orbits and Sizes

    Two distinct populations of dark comets delineated by orbits and sizes. Proceedings of the National Academy of Science , keywords =. doi:10.1073/pnas.2406424121 , archivePrefix =. 2412.07603 , primaryClass =

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.1073/pnas.2406424121

  62. [62]

    , keywords =

    Dark Comets? Unexpectedly Large Nongravitational Accelerations on a Sample of Small Asteroids. , keywords =. doi:10.3847/PSJ/acb697 , archivePrefix =. 2212.08115 , primaryClass =

    work page doi:10.3847/psj/acb697

  63. [63]

    , keywords =

    (523599) 2003 RM: The Asteroid that Wanted to be a Comet. , keywords =. doi:10.3847/PSJ/acb25b , archivePrefix =. 2212.08135 , primaryClass =

    work page doi:10.3847/psj/acb25b 2003

  64. [64]

    , keywords =

    Snapshot of a new interstellar comet: 3I/ATLAS has a red and featureless spectrum. , keywords =. doi:10.1093/mnrasl/slaf095 , archivePrefix =. 2507.05226 , primaryClass =

    work page doi:10.1093/mnrasl/slaf095

  65. [65]

    , keywords =

    Near-discovery Observations of Interstellar Comet 3I/ATLAS with the NASA Infrared Telescope Facility. , keywords =. doi:10.3847/2041-8213/adfbdf , archivePrefix =. 2507.12234 , primaryClass =

    work page doi:10.3847/2041-8213/adfbdf 2041

  66. [66]

    The Astronomer's Telegram , keywords =

    Interstellar Interloper C/2025 N1 is Active. The Astronomer's Telegram , keywords =

    2025

  67. [67]

    , keywords =

    Spectroscopic Characterization of Interstellar Object 3I/ATLAS: Water Ice in the Coma. , keywords =. doi:10.3847/2041-8213/ae08a7 , archivePrefix =. 2507.14916 , primaryClass =

    work page doi:10.3847/2041-8213/ae08a7 2041

  68. [68]

    Rubin Observatory Observations of Interstellar Comet 3I/ATLAS (C/2025 N1)

    NSF-DOE Vera C. Rubin Observatory Observations of Interstellar Comet 3I/ATLAS (C/2025 N1). arXiv e-prints , keywords =

    2025

  69. [69]

    Research Notes of the American Astronomical Society , keywords =

    Palomar and Apache Point Spectrophotometry of Interstellar Comet 3I/ATLAS. Research Notes of the American Astronomical Society , keywords =. doi:10.3847/2515-5172/adf059 , archivePrefix =. 2507.11720 , primaryClass =

    work page doi:10.3847/2515-5172/adf059

  70. [70]

    , keywords =

    Assessing interstellar comet 3I/ATLAS with the 10.4 m Gran Telescopio Canarias and the Two-meter Twin Telescope. , keywords =. doi:10.1051/0004-6361/202556439 , archivePrefix =. 2507.12922 , primaryClass =

    work page doi:10.1051/0004-6361/202556439

  71. [71]

    The Astronomer's Telegram , keywords =

    Deep g'-band Imaging of Interstellar Comet 3I/ATLAS from the Two-meter Twin Telescope (TTT). The Astronomer's Telegram , keywords =

  72. [72]

    , keywords =

    Near-Discovery SOAR Photometry of the Third Interstellar Object: 3I/ATLAS. , keywords =. doi:10.1093/mnras/staf1994 , archivePrefix =. 2509.02813 , primaryClass =

    work page doi:10.1093/mnras/staf1994

  73. [73]

    arXiv e-prints , keywords =

    Pre-discovery TESS Observations of Interstellar Object 3I/ATLAS. arXiv e-prints , keywords =

  74. [74]

    Nature Astronomy , keywords =

    The carbon monoxide-rich interstellar comet 2I/Borisov. Nature Astronomy , keywords =. doi:10.1038/s41550-020-1095-2 , archivePrefix =. 2004.08972 , primaryClass =

    work page doi:10.1038/s41550-020-1095-2 2004

  75. [75]

    Nature Astronomy , keywords =

    Unusually high CO abundance of the first active interstellar comet. Nature Astronomy , keywords =. doi:10.1038/s41550-020-1087-2 , archivePrefix =. 2004.09586 , primaryClass =

    work page doi:10.1038/s41550-020-1087-2 2004

  76. [76]

    arXiv e-prints , keywords =

    Spatial Profiles of 3I/ATLAS CN and Ni Outgassing from Keck/KCWI Integral Field Spectroscopy. arXiv e-prints , keywords =

  77. [77]

    arXiv e-prints , keywords =

    JCMT detection of HCN emission from 3I/ATLAS at 2.1 AU. arXiv e-prints , keywords =. doi:10.48550/arXiv.2510.02817 , archivePrefix =. 2510.02817 , primaryClass =

    work page doi:10.48550/arxiv.2510.02817

  78. [78]

    arXiv e-prints , keywords =

    Extreme NiI/FeI abundance ratio in the coma of the interstellar comet 3I/ATLAS. arXiv e-prints , keywords =. doi:10.48550/arXiv.2509.26053 , archivePrefix =. 2509.26053 , primaryClass =

    work page doi:10.48550/arxiv.2509.26053

  79. [79]

    , keywords =

    Prediscovery Activity of New Interstellar Object 3I/ATLAS: Rapid Brightening from 6 to 4 au. , keywords =. doi:10.3847/2041-8213/ae147b , archivePrefix =. 2509.08792 , primaryClass =

    work page doi:10.3847/2041-8213/ae147b 2041

  80. [80]

    arXiv e-prints , keywords =

    ATLAS Photometry of Interstellar Object 3I/ATLAS. arXiv e-prints , keywords =. doi:10.48550/arXiv.2509.05562 , archivePrefix =. 2509.05562 , primaryClass =

    work page doi:10.48550/arxiv.2509.05562

Showing first 80 references.