REVIEW 4 major objections 5 minor 1 cited by
Jets are the most robust observable ingredient of common envelope evolution
T0 review · 4 major / 5 minor · reviewed 2026-08-11 · deepseek-v4-flash
Pith's one-line read Jets outnumber dense rings in post-common-envelope nebulae by about 40 percent, making them the most robust observable signature of common envelope evolution.
desk verdict The first systematic count of jets vs. rings in post-CEE PNe, yielding a ratio that is plausible but rests on subjective classification and an image-selected subset. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The counting device is a morphological classification of public images into robust jet signatures (1), likely jet signatures (0.5), and no jets (0), with a parallel classification for equatorial rings, tori, and disks. Its output is the ratio $Q_{\mathrm{JR,obs}} = (N_{\rm jets} + N_{\rm likely\ jets})/(N_{\rm rings} + N_{\rm likely\ rings}) \simeq 1.4$, corrected to $Q_{\mathrm{JR,CEE}} \simeq 2\,Q_{\mathrm{JR,obs}} \gtrsim 3$ to account for fast jet dispersal and for rings compressed by jets. The physical mechanism invoked is a main-sequence companion accreting mass from the giant envelope and launching jets through an accretion disk, with accretion energy $E_{\rm acc} = G M_{\rm MS} M_{\rm acc}/(2R_{\rm MS})$ able to dominate the orbital energy $E_{\rm orb} = G M_{\rm MS} M_{\rm core}/(2a)$ for $a \gtrsim (M_{\rm core}/M_{\rm acc}) R_{\rm MS} \simeq 10\,(M_{\rm core}/20M_{\rm acc})\,(R_{\rm MS}/0.5R_\odot)\,R_\odot$.
What would settle it
Re-score the same 50 images in a blind, multi-rater study with clear jet and ring criteria; the central claim stands only if the median jetted-to-ring ratio remains above 1.
Extended reading notes
Core claim
The central claim is that jets are the most robust observable ingredient of common envelope evolution: in a sample of 50 planetary nebulae with known post-common-envelope binary central stars, 28 show clear jet morphologies and 8 more show likely jets, while only 25 show a dense equatorial outflow in the form of a disk, torus, or ring. This gives an observed jetted-to-ring ratio $Q_{\mathrm{JR,obs}}\simeq 1.4$. The author argues the underlying common envelope process launches jets even more often, roughly twice the observed ratio, because jets disperse quickly and because some equatorial outflows are compressed by jets rather than ejected directly by the common envelope. The jets are attributed to accretion onto the main-sequence companion before, during, or shortly after the common envelope phase, and this accretion carries an energy budget comparable to or larger than the orbital energy released at the relevant orbital radii.
Load-bearing premise
The count rests on the author's visual reading of public images, assuming that morphologies robustly suggesting jets are true jets and that the 50 nebulae with high-quality images are not biased toward jet-shaped objects.
Editorial extensions
If this is right
- Numerical simulations of common envelope evolution that omit jets are missing an ingredient that appears in at least 72% of the best-studied post-common-envelope nebulae.
- Accretion onto the companion, required to launch the jets, deposits energy comparable to the orbital energy released during inspiral, so jet-launching should be included in mass-removal and final-orbit calculations.
- The observed 40% excess of jets over rings is a lower limit; deeper, younger, or Doppler-resolved observations should push the jetted-to-ring ratio toward 3 or higher.
- Some planetary nebulae classified as having equatorial rings may have acquired those rings from jet compression rather than direct common-envelope ejection, so ring counts may not directly measure the equatorial ejection rate.
Reading between the lines
- If the true jet-to-ring ratio is at least 3, jet feedback may be a deciding factor in whether the envelope is ejected and how much the orbit shrinks, so population-synthesis predictions for post-common-envelope binaries should treat jet-launching as the default rather than the exception.
- A direct test of the detection-bias correction would be deep radial-velocity mapping of a sample of the nebulae classified as having no jets: if hidden jet pairs appear in even a few, the observed ratio will move toward the paper's corrected value.
- The same accretion-jet mechanism may operate in other common-envelope outcomes, such as subdwarf binaries or merging white dwarfs, where jet-launched outflows could be observable in a similar morphological census.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. This paper examines images of 50 planetary nebulae with known binary central stars from the Jones catalog and classifies each for the presence of jets (robust or likely) and equatorial outflows/rings (robust, likely, or absent). The author reports that 36 of 50 show jet signatures and 25 of 50 show ring signatures, giving a jetted-to-ring ratio QJR,obs ≈ 1.4, and argues that after correcting for detectability biases and the possibility that jets create some rings, the true ratio from common envelope evolution (CEE) is at least 3. The paper concludes that jets are a more robust observable ingredient of CEE than equatorial outflows and that numerical simulations of CEE must include jets. It also sketches an energy-budget argument showing that accretion energy from the companion can dominate orbital energy at large radii.
Significance. If the reported ratio holds, it would strengthen the case that jet-launching is a frequent, even dominant, outcome of common envelope interactions and would provide a direct observational constraint on CEE simulations. The table of 50 classified PNe with references is a useful community resource, and the author is explicitly transparent that the correction factor in Eq. (2) is a crude estimate. However, the central quantitative claim rests on a subjective, single-author morphological classification and on a sample of only 50 of 108 available binary PNe selected by image quality, without analysis of selection effects. The paper also overreaches in its title and abstract by presenting the speculative correction as a firm conclusion. These issues are fixable in revision, but they currently limit the strength of the claims.
major comments (4)
- [Section 2] Sample selection bias is load-bearing: the sample consists of 50 of 108 binary PNe from the Jones catalog for which the author could find high-quality images, with no comparison between the 50 included and the 58 excluded objects. Because jet features are extended and may fade with nebular age while equatorial rings remain bright, an image-availability selection could systematically inflate the observed jet fraction. The paper acknowledges this by encouraging further studies, but it does not quantify the possible effect on QJR,obs. The central claim of the paper therefore has no demonstrated robustness to the 58 excluded systems.
- [Section 2 and Table 1] The morphological classifications are performed by the author alone, without a pre-defined objective rubric, blind conditions, or inter-rater check. The reported ratio QJR,obs = 36/25 = 1.44 counts the '0.5' (likely) category as positive for both jets and rings; if only 'robust' classifications are used, the ratio becomes 28/13 ≈ 2.2, which is materially different. The paper provides no error bars or sensitivity analysis to the classification threshold, so the reader cannot assess whether the conclusion that jets are more common by 40% is stable under alternative reasonable classifications.
- [Section 3.1, Eq. (2)] The corrected ratio QJR,CEE ≈ 2 × QJR,obs ≳ 3 is based on the argument that jets can create equatorial rings (citing Akashi et al. 2015 and Shiber 2018), yet the observed ratio in Eq. (1) counts rings as a separate, independent outcome. If jets can produce rings, then the same observed PNe contain both features, and the correction is not an inference from the data but an assumption that the underlying CEE process produces even more jets. The paper calls this a crude estimate, but the abstract elevates it to a conclusion ('likelier to launch jets than to eject a dense equatorial outflow by a larger factor than 1.4'). This extrapolation should be clearly separated from the measured census, and the abstract should not present Eq. (2) as an established result.
- [Sections 1 and 3.3] The paper defines 'CEE jets' to include jets launched during a pre-CEE grazing envelope evolution (GEE) phase and during the post-CEE phase. However, the sample of binary PNe includes systems with orbital periods as long as 142 days (NGC 1360), which may have undergone GEE rather than a full CEE. Because the title and abstract claim a conclusion about CEE specifically, the inclusion of non-CEE systems without separate analysis weakens the direct inference. The authors should either restrict the claim to systems where CEE is confirmed, or reframe the conclusion as applying to the broader binary-interaction process.
minor comments (5)
- [Section 3.1] The text refers to 'NGC 2392 (panel c of Figure 1)', but NGC 2392 is panel (d); the Necklace is panel (c).
- [Table 2] The table presents counts as percentages but the numbers are integers summing to 100; the note should explicitly state that entries are percentages (e.g., 18% = 9 of 50 objects).
- [Acknowledgements] The sentence 'Our group, whose recent proposal was rejected' is inappropriate for a scientific paper and should be removed.
- [References] The reference 'Scolnic, A., Bear, E., Soker, N., 2025, arXiv, to be posted on January 7' cites a paper not yet available; this should be updated once posted.
- [General] The paper uses a journal template header 'RAA Vol.0 (20xx) No.0' which should be corrected in the final version.
Circularity Check
No significant circularity: the jet/ring counts are external observations and the factor-2 correction is an explicitly crude estimate, not a fitted parameter.
full rationale
The central observational result, QJR,obs ≃ 1.4, is obtained by classifying images of 50 PNe from Jones's external binary-CSPN catalog (Section 2, Table 1, Table 2, Eq. 1). These counts are not derived from any model parameter fitted in this paper, and no equation in the paper reduces to its own input. The Section 3.1 correction QJR,CEE ≈ 2 × QJR,obs is not a prediction forced by construction: the factor 2 is introduced as a crude estimate ('I crudely estimate') based on the presence of barely detected jets, and the cited support for jet-shaped rings (Akashi et al. 2015; Shiber 2018) consists of three-dimensional hydrodynamical simulations from prior work rather than an unverified assumption of the present result. Although several references are to the author's own group, they are background or independent numerical evidence, so the self-citation is not load-bearing. The Acknowledgements' note that the group's recent proposal was rejected is a resource limitation, not circularity. The absence of an inter-rater reliability check is a methodological limitation affecting classification robustness, not circularity. The derivation chain is therefore self-contained with respect to circularity, though selection and classification biases remain a separate correctness risk.
Assumptions & free parameters
free parameters (3)
- Intrinsic-to-observed jetted-to-ring correction factor =
2 (QJR,CEE ≈ 2 × QJR,obs ≈ 3)
- Typical CEE binary parameters for energy-budget illustration =
MMS=0.15-0.4 Msun; RMS=0.4-0.7 Rsun; Mcore=0.5-0.7 Msun; Macc≈0.03 Msun
- Fraction of accretion energy carried by jets =
0.1-0.2
assumptions (5)
- domain assumption PNe with short-period binary central stars experienced common envelope evolution, so the sample probes post-CEE systems.
- domain assumption Morphological signatures such as opposite lobes, ansae, and point-symmetric structures are produced by jets.
- domain assumption Dense equatorial rings remain observable longer than fast dispersing jets, so the observed ratio underestimates the true CEE jetted-to-ring ratio.
- domain assumption Jets can shape or compress ambient gas into equatorial rings, so some observed rings may be jet products rather than direct CEE equatorial ejections.
- domain assumption The common envelope itself does not launch the precessing jets; an accreting companion does.
Cite this review
Pith. "Pith review of Jets are the most robust observable ingredient of common envelope evolution." pith.science (2026). https://pith.science/paper/U5HS5TNQ
@misc{pith2026241204017,
author = {Pith},
title = {Pith review of: Jets are the most robust observable ingredient of common envelope evolution},
year = {2026},
howpublished = {\url{https://pith.science/paper/U5HS5TNQ}},
note = {Machine review of arXiv:2412.04017}
}
read the original abstract
I examine images of 50 planetary nebulae (PNe) with observable post-common envelope evolution (CEE) binary central stars and find that jets are about 40 percent more common than dense equatorial outflows. Because, in some cases, energetic jets can compress an equatorial outflow and because fast jets might disperse early in the PN evolution and avoid detection, the CEE process is likelier to launch jets than to eject a dense equatorial outflow by a larger factor than 1.4. In most cases, the companion, mainly a main sequence star, launches the jets as it accretes mass from the envelope of the giant star. By CEE jets, I also refer to jets launched shortly before the onset of the CEE, likely a grazing envelope evolution phase, and shortly after the CEE. The jets and the accretion of mass by the companion before, during, and after the CEE affect envelope mass removal and the final orbital separation. Most numerical simulations of the CEE ignore jets, and those that include jets omit other processes. Despite the considerable progress in the last decade with tens of hydrodynamical simulations of the CEE, we are still far from correctly simulating the CEE. Including jets in simulations of the CEE requires heavy computer resources, but it must be the next step.
Figures
Forward citations
Cited by 1 Pith paper
-
Hyperaccreting Magnetised Neutron Stars inside Rotating Massive Envelopes: Low-Power Jets and Precursor Flares
In 2D GRMHD simulations, magnetised neutron stars hyperaccreting inside massive envelopes can halt accretion above B_surf ~2.3e13 G and launch ~1e46 erg/s precursor jets that still cannot unbind the envelope.
Reference graph
Works this paper leans on
-
[1]
2015, MNRAS, 453, 2115, doi: 10.1093/mnras/ stv1666 Akashi, M., & Soker, N
Akashi, M., Sabach, E., Yogev, O., & Soker, N. 2015, MNRAS, 453, 2115, doi: 10.1093/mnras/ stv1666 Akashi, M., & Soker, N. 2018, MNRAS, 481, 2754, doi: 10.1093/mnras/sty2479 Aller, A., Lillo-Box, J., & Jones, D. 2024, A&A, 690, A190, doi: 10.1051/0004-6361/202450942 Aller, A., Lillo-Box, J., Jones, D., Miranda, L. F., & Barcel´o Forteza, S. 2020, A&A, 635...
doi:10.1093/mnras/ 2015
-
[4]
48550/arXiv.2410.03589 Blackman, E. G., & Lucchini, S. 2014, MNRAS, 440, L16, doi: 10.1093/mnrasl/slu001 Boffin, H. M. J., & Jones, D. 2019, The Importance of Binaries in the Formation and Evolution of Planetary Nebulae, doi: 10.1007/978-3-030-25059-1 Boffin, H. M. J., Miszalski, B., Rauch, T., et al. 2012, Science, 338, 773, doi: 10.1126/science. 1225386...
arXiv 2014
-
[5]
1086/307768 Corradi, R. L. M., Sabin, L., Miszalski, B., et al. 2011, MNRAS, 410, 1349, doi: 10.1111/j.1365-2966. 2010.17523.x Corradi, R. L. M., Rodr´ıguez-Gil, P., Jones, D., et al. 2014, MNRAS, 441, 2799, doi: 10.1093/mnras/stu703 Danehkar, A. 2022, ApJS, 260, 14, doi: 10.3847/ 1538-4365/ac5cca De Marco O., Passy J.-C., Moe M., Herwig F., Mac Low M.-M....
-
[7]
1051/0004-6361/202348383 Gagnier D., Pejcha O., 2024, arXiv, arXiv:2412.04419 Garc´ıa-D´ıaz, M. T., L ´opez, J. A., Garc ´ıa-Segura, G., Richer, M. G., & Steffen, W. 2008, ApJ, 676, 402, doi: 10.1086/527468 Garc´ıa-Segura, G., Taam, R. E., & Ricker, P. M. 2020, ApJ, 893, 150, doi: 10.3847/1538-4357/ab8006 —. 2021, ApJ, 914, 111, doi: 10.3847/1538-4357/ ab...
arXiv 2024
-
[8]
A., Cazzoli, S., Rechy-Garc ´ıa, J
1093/mnras/stac2301 Guerrero, M. A., Cazzoli, S., Rechy-Garc ´ıa, J. S., et al. 2021, ApJ, 909, 44, doi: 10.3847/1538-4357/ abe2aa Guerrero, M. A., & Miranda, L. F. 2012, A&A, 539, A47, doi: 10.1051/0004-6361/201117923 Guerrero, M. A., Suzett Rechy-Garc ´ıa, J., & Ortiz, R. 2020, ApJ, 890, 50, doi: 10.3847/1538-4357/ ab61fa Gurjar, D., Chamandy, L. R., Zo...
-
[10]
1051/0004-6361/201937118 Baan, W. A., Imai, H., & Orosz, G. 2021, Research in Astronomy and Astrophysics, 21, 275, doi: 10.1088/ 1674-4527/21/11/275 Balick, B. 2006, Planetary Nebula Image Catalogue: HST data, HST Proposal ID 10933. Cycle 15 Balick, B., Frank, A., & Liu, B. 2020, ApJ, 889, 13, doi: 10.3847/1538-4357/ab5651 Balick B., Rugers M., Terzian Y ...
-
[11]
1093/mnras/stz2312 Iaconi, R., Maeda, K., Nozawa, T., De Marco, O., & Reichardt, T. 2020, MNRAS, 497, 3166, doi:
work page 2020
-
[13]
48550/arXiv.2411.06831 Jones, D., & Boffin, H. M. J. 2017, Nature Astronomy, 1, 0117, doi: 10.1038/s41550-017-0117 Jones, D., Boffin, H. M. J., Miszalski, B., et al. 2014, A&A, 562, A89, doi: 10.1051/0004-6361/201322797 Jones, D., Boffin, H. M. J., Rodr ´ıguez-Gil, P., et al. 2015, A&A, 580, A19, doi: 10.1051/0004-6361/ 201425454 Jones, D., Boffin, H. M. ...
arXiv 2017
Show all 21 references
-
[14]
2010, MNRAS, 408, 2312, doi: 10.1111/j.1365-2966
1093/mnras/stv2519 Jones, D., Lloyd, M., Santander-Garc ´ıa, M., et al. 2010, MNRAS, 408, 2312, doi: 10.1111/j.1365-2966. 2010.17277.x Jones, D., Boffin, H. M. J., Hibbert, J., et al. 2020, A&A, 642, A108, doi: 10.1051/0004-6361/ 202038778 Jones, D., Munday, J., Corradi, R. L....
2010
-
[15]
A., Roth, M., & Tapia, M
48550/arXiv.2011.06630 Lopez, J. A., Roth, M., & Tapia, M. 1993, A&A, 267, 194 L´opez-C´amara, D., De Colle, F., & Moreno M ´endez, E. 2019, MNRAS, 482, 3646, doi: 10.1093/mnras/ sty2959 L´opez-C´amara, D., De Colle, F., Moreno M ´endez, E., Shiber, S., & Iaconi, R. 2022, MNRA...
2011 arXiv
-
[16]
2019a, PASA, 36, e042, doi: 10.1017/pasa.2019.36 Miszalski, B., Manick, R., Van Winckel, H., & Escorza, A
1017/pasa.2018.23 Miszalski, B., Manick, R., Rauch, T., et al. 2019a, PASA, 36, e042, doi: 10.1017/pasa.2019.36 Miszalski, B., Manick, R., Van Winckel, H., & Escorza, A. 2019b, PASA, 36, e018, doi:10.1017/pasa.2019. 11 Jets are the most robust observables of CEE 9 Miszalski, B...
2018 arXiv
-
[17]
A., Redman, M
48550/arXiv.2406.04118 O’Connor, J. A., Redman, M. P., Holloway, A. J., et al. 2000, ApJ, 531, 336, doi: 10.1086/308452 Ohlmann, S. T., R ¨opke, F. K., Pakmor, R., & Springel, V . 2016, ApJL, 816, L9, doi: 10.3847/2041-8205/ 816/1/L9 Ondratschek, P. A., R¨opke, F. K., Schneide...
2000
-
[19]
2017, MNRAS, 472, 4361, doi: 10.1093/mnras/ stx2272 Sahai, R., Claussen, M., S ´anchez Contreras, C., Morris, M., & Sarkar, G
48550/arXiv.2404.08037 Sabach, E., Hillel, S., Schreier, R., & Soker, N. 2017, MNRAS, 472, 4361, doi: 10.1093/mnras/ stx2272 Sahai, R., Claussen, M., S ´anchez Contreras, C., Morris, M., & Sarkar, G. 2008, ApJ, 680, 483, doi: 10.1086/ 587638 Sahai, R., Morris, M. R., & Villar,...
2017 arXiv
-
[20]
1086/300504 Sahai, R., Vlemmings, W. H. T., & Nyman, L. ˚A. 2017, ApJ, 841, 110, doi: 10.3847/1538-4357/aa6d86 Sahai, R., Alcolea, J., Balick, B., et al. 2024, arXiv e- prints, arXiv:2409.06038. https://arxiv.org/ abs/2409.06038 Santander-Garc´ıa, M., Rodr ´ıguez-Gil, P., Corr...
2017 arXiv
-
[21]
A., Guerrero, M
1051/0004-6361/201834632 Toal´a, J. A., Guerrero, M. A., Bianchi, L., Chu, Y . H., & De Marco, O. 2020, MNRAS, 494, 3784, doi: 10.1093/ mnras/staa1024 10 N. Soker Tocknell, J., De Marco, O., & Wardle, M. 2014, MNRAS, 439, 2014, doi: 10.1093/mnras/stu079 Van Winckel H., Jorisse...
-
[22]
C., & Nordhaus, J
1093/mnras/sty1871 Wilson, E. C., & Nordhaus, J. 2019, MNRAS, 485, 4492, doi: 10.1093/mnras/stz601 —. 2020, MNRAS, 497, 1895, doi: 10.1093/mnras/ staa2088 —. 2022, MNRAS, 516, 2189, doi: 10.1093/mnras/ stac2300 Zou, Y ., Chamandy, L., Carroll-Nellenback, J., Blackman, E. G., &...
2019 doi
-
[23]
2020, MNRAS, 497, 2855, doi: 10.1093/mnras/staa2145
1093/mnras/stac1529 Zou, Y ., Frank, A., Chen, Z., et al. 2020, MNRAS, 497, 2855, doi: 10.1093/mnras/staa2145
2020 doi
-
[96]
2024, MNRAS, 532, 692, doi:10
doi:10.3390/galaxies6030096 Shiber, S., & Iaconi, R. 2024, MNRAS, 532, 692, doi:10. 1093/mnras/stae1500 Shiber, S., Iaconi, R., De Marco, O., & Soker, N. 2019, MNRAS, 488, 5615, doi: 10.1093/mnras/ stz2013 Shiber, S., Schreier, R., & Soker, N. 2016, Research in Astronomy and A...
2024
-
[319]
C., Frew, D
doi:10.1088/0004-6256/140/2/319 Hillwig, T. C., Frew, D. J., Louie, M., et al. 2015, AJ, 150, 30, doi: 10.1088/0004-6256/150/1/30 Hillwig, T. C., Frew, D. J., Reindl, N., et al. 2017, AJ, 153, 24, doi: 10.3847/1538-3881/153/1/24 Hillwig, T. C., Jones, D., De Marco, O., et al. ...
2015 doi
-
[778]
doi:10.48550/arXiv.2407.03182 Berm´udez-Bustamante, L
doi:10.1086/172881 Bear E., Soker N., 2025, arXiv, arXiv:2407.03182. doi:10.48550/arXiv.2407.03182 Berm´udez-Bustamante, L. C., De Marco, O., Siess, L., et al. 2024a, MNRAS, 533, 464, doi: 10.1093/ mnras/stae1841 —. 2024b, MNRAS, 533, 464, doi: 10.1093/mnras/ stae1841 Bhattach...
-
[2277]
2024, MNRAS, 530, 3327, doi: 10.1093/mnras/stae1013 Estrella-Trujillo, D., Hern ´andez-Mart´ınez, L., Vel ´azquez, P
doi:10.1111/j.1365-2966.2010.17891.x Derlopa, S., Akras, S., Amram, P., et al. 2024, MNRAS, 530, 3327, doi: 10.1093/mnras/stae1013 Estrella-Trujillo, D., Hern ´andez-Mart´ınez, L., Vel ´azquez, P. F., Esquivel, A., & Raga, A. C. 2019, ApJ, 876, 29, doi: 10.3847/1538-4357/ab12e...
2010
Reviewed August 11, 2026 · model on record in the stance chip above.
Discussion (0). Continue with ORCID to comment.