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Exploring the optical properties of redback pulsars: The case of J1717+4308A in the globular cluster M92

T0 review · 3 major / 4 minor · reviewed 2026-08-01 · deepseek-v4-flash

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Pith's one-line read A star just 0.02 arcseconds from the radio position of PSR J1717+4308A is its optical companion, and the system's light curve reveals a hot, low-mass companion and a neutron star near 2.3 solar masses.

desk verdict Counterpart identification is convincing, but the headline masses and temperature depend on untested gravity-darkening and prior choices; the system is real, the parameters are conditional. read the letter →

arxiv 2607.22289 v1 pith:2IGCGXND submitted 2026-07-24 astro-ph.HE astro-ph.SR

Jianxing Chen , Greta Ettorre , Cristina Pallanca , Mario Cadelano , Bidisha Sen , Devina Misra , Emanuele Dalessandro , Francesco R. Ferraro
show 8 more authors
Barbara Lanzoni Alessandro Ridolfi Marta Burgay Andrea Possenti Paulo C. C. Freire Scott M. Ransom Manuel Linares Rene P. Breton
This is my paper
classification astro-ph.HEastro-ph.SR
keywords redbackpulsarsmillisecondglobularclusterM92opticalcounterpartlight-curvemodelingellipsoidalvariabilityneutronstarmassHSTphotometry
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper sets out to find and characterize the optical companion to the redback millisecond pulsar J1717+4308A in the globular cluster M92. Using multi-epoch HST imaging in seven filters, it identifies a star 0.02 arcseconds from the radio position that is bluer than the main sequence, a cluster member by proper motion, and variable with the 0.2-day orbital period. Modeling the double-humped, ellipsoidal light curve yields an orbital inclination near 79 degrees, a companion mass of about 0.23 solar masses, and a neutron star mass of roughly 2.3 solar masses. The companion's base temperature of about 7200 K places it among the hottest redback companions known, second only to PSR J1431-4715. If the identification holds, M92A becomes a rare cluster redback with a massive neutron star and an unusually hot companion, offering a test case for binary evolution and recycling scenarios.

What carries the argument

The Icarus binary light-curve synthesis code, using ATLAS9 atmosphere grids, is the central tool: it converts phase-folded multi-filter photometry into physical parameters by modeling the companion as a Roche-lobe-filling, tidally distorted star whose surface is darkened and irradiated by the pulsar wind. The key observed feature is the double-humped ellipsoidal modulation, which encodes inclination and masses. The paper also uses the spin-down-to-companion-flux ratio fsd of about 2.71 to place M92A near the transition between ellipsoidal- and irradiation-dominated light curves.

What would settle it

A phase-resolved optical spectrum of COM-M92A that measures the projected radial-velocity semi-amplitude K2: if K2 is not approximately 433 km/s, or if rotational broadening indicates non-synchronous rotation, the light-curve solution and the derived neutron-star mass of about 2.3 solar masses would be wrong. An independent check would be a precise neutron-star mass from pulsar timing, such as through the Shapiro delay or the rate of periastron advance, which would directly test the massive-neutron-star claim.

Watch

Extended reading notes

Core claim

The authors argue that COM-M92A, the star 0.02 arcseconds from the radio timing position of PSR J1717+4308A, is the optical companion to this redback pulsar. They base this on three independent lines of evidence: the star sits within the combined 3-sigma position uncertainty of the radio source; its proper motion matches the cluster M92's bulk motion, ruling out a field interloper; and its flux varies with the binary orbital period in a double-maxima/double-minima pattern typical of a tidally distorted star seen at high inclination. Light-curve modeling with the Icarus synthesis code, assuming tidal locking and a gravity-darkening law for a convective envelope, gives i around 79 degrees, mas

Load-bearing premise

The derived masses and temperature depend on the companion being tidally locked and obeying the assumed gravity-darkening law for a convective envelope (co-rotation factor omega = 1 and beta = 0.08); if the star rotates differently or its envelope is partly radiative, the ellipsoidal light-curve inversion shifts, and with it the companion mass, neutron-star mass, and the claim that 7200 K is anomalously hot.

Editorial extensions

If this is right

  • If the parameters are correct, the neutron star mass of about 2.3 solar masses is at the high end for neutron stars in globular clusters, providing a constraint on the dense-matter equation of state.
  • The companion temperature of about 7200 K makes M92A an outlier among redbacks, which typically have companions cooler than 6000 K, suggesting an atypical evolutionary history or a special formation channel in a dense cluster.
  • The high inclination and low irradiation of the system make it a promising target for future phase-resolved spectroscopy and eclipse timing to verify the orbital geometry and the derived masses.
  • Adding M92A to the small sample of cluster redbacks with fully modeled light curves allows for population comparisons with field redbacks and tests of the fsd boundary between ellipsoidal- and irradiation-dominated regimes.

Reading between the lines

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

  • A direct radial-velocity measurement of the companion via phase-resolved spectroscopy could independently confirm the projected semi-amplitude K2 of about 433 km/s; if K2 differs significantly, the inclination and masses derived from the ellipsoidal fit would need revision.
  • The second-hottest status hints that redback companion temperatures may not form a single population; if more cluster redbacks are found with hot companions, the assumed relationship between irradiation efficiency and light-curve morphology may need recalibration.
  • The best-fit solution leaves a small unrecovered phase-dependent residual; with more epochs, including spots or asymmetric heating in the model could shift the derived base temperature and Roche-lobe filling factor.
  • Because the analysis truncates the neutron-star prior at 3 solar masses, the reported M1 = 2.3 +/- 0.5 solar masses is a lower-tail estimate; a prior extending to higher masses would change the posterior shape, and a future precise mass from pulsar timing would provide a sharp test.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 4 minor

Summary. The paper identifies COM-M92A, a star located 0.02 arcsec from the radio position of PSR J1717+4308A in M92, as the likely optical companion of this redback pulsar. The identification is based on astrometric proximity, cluster membership from proper motions, location in the CMD, and phase-folded photometric variability at the radio orbital period. The authors then model the seven-filter HST light curves with the Icarus code, fitting orbital inclination, K2, Roche-lobe filling factor, base/irradiation temperatures, distance, and extinction. The best-fit model gives i≈79 deg, q≈10, M2≈0.23 Msun, M1≈2.3 Msun, and T_base≈7191 K, placing the companion among the hottest redbacks known. The paper concludes that mild irradiation is consistent with the spin-down-to-companion flux ratio f_sd≈2.71, and discusses the system's evolutionary implications.

Significance. If the inferred parameters are robust, the identification is a valuable addition to the small sample of redback pulsar companions in globular clusters, and the system is notable for its hot companion and possibly massive neutron star. The identification itself is strong and multi-probe: the 0.02 arcsec offset, the proper-motion membership, the photometric variability only at the radio period, and the clean PSF subtraction together make a convincing case. However, the quantitative light-curve results — and hence the mass and temperature claims — rest on a fixed gravity-darkening prescription that is in tension with the fitted temperature, and on a quietly imposed neutron-star-mass cap. These issue need to be addressed before the physical claims can be taken at face value.

major comments (3)
  1. [Sect. 3.2, Table 1] The headline parameters are derived with two fixed assumptions: co-rotation (omega=1) and Lucy (1967) gravity darkening beta=0.08, justified by a convective envelope. The fitted T_base=7191 K (with T_sup/T_inf~7050 K) places the star in a regime where a radiative envelope and beta~0.25 may be more appropriate. Since the ellipsoidal amplitude is converted into (i, f, K2) through the assumed surface-brightness distribution, beta directly affects the derived masses. The posterior is also truncated by a prior M1<3 Msun, which can hide the direction of the shift. Please present a refit with beta=0.25 (or a marginalization over beta), and report the fraction of posterior samples near the mass-cap boundary.
  2. [Sect. 4] The f_sd~2.71 argument is partially circular: it is computed using T_base from the same Icarus fit and then compared with the empirical transition boundary of Turchetta et al. (2023). This does not independently confirm the 'mild irradiation' interpretation; it is a consistency check with the same model-dependent temperature scale. I request a range of f_sd from the posterior of T_base (and independent estimates of L_sd), and a more cautious wording of the irradation conclusion.
  3. [Fig. 4, Sect. 4] The paper itself notes an unrecovered phase-dependent residual structure, attributed to limited statistics. Given that the surface-brightness model is the load-bearing part of the parameter inference, this is not merely a cosmetic issue. Please quantify the residuals (per-filter rms, phase-binned residuals) and discuss whether a different beta or an additional physical component could remove them. This is directly relevant to the credibility of the derived masses and temperatures.
minor comments (4)
  1. [Sect. 3.2] The resampling step that randomly draws 20 data points per filter with replacement discards information and introduces stochasticity into the fit. A weighted likelihood using all data points would be preferable, or at least a seed-independent demonstration that the results are stable.
  2. [Fig. 6] A_V closely follows its prior and D is prior-dominated; the paper should state explicitly that the HST light curves do not constrain extinction or distance beyond their priors.
  3. [Table 1] Please clarify the relation between T_base, T_sup, and T_inf: the quoted values are nearly identical, which is surprising for a strongly irradiated redback; a brief explanation of how gravity darkening and irradiation combine would help.
  4. [References and text] Minor editorial items: 'Turchetta et al 2023' is missing a dot; 'Bobakov et al. 2024, 2025' entries are not uniformly formatted; and the symbol f_sd is written both as f_sd and fsd in places. Also, Fig. 1 mixes '3σ uncertainty' with the quoted 13 mas astrometric accuracy; please define the combined uncertainty explicitly.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: companion identification and light-curve fit are self-contained; the f_sd argument is a post-fit consistency check, not a forced prediction.

full rationale

The paper's derivation chain does not reduce to its inputs. The companion identification (Sect. 3.1) rests on independent evidence: a 0.02″ offset from the radio timing position, cluster-member proper motion from HACKS, an out-of-sequence CMD position, and photometric variability phased to the radio orbital period; none of these is defined in terms of the fitted light-curve parameters. The light-curve modeling (Sect. 3.2) is a standard forward-model fit with the public Icarus code and ATLAS9 atmospheres, anchored to the radio-derived x1 and Porb and to external distance/extinction priors; the fitted i, K2, f, Tbase, Tirr and derived q, M1, M2 are posterior results, not recycled constraints. The only same-team citation entering the interpretation is the f_sd boundary of Turchetta et al. (2023), used as a post-fit consistency check (f_sd ≈ 2.71 computed from radio L_sd and the fitted Tbase), while Tirr is a separately fitted parameter whose posterior peaks near zero. The agreement is therefore a non-forced consistency statement, not a constructional identity. The fixed tidally-locked/β=0.08 assumption, the M_NS < 3 M☉ prior, and the noted unrecovered phase-dependent residuals (Sect. 4) are model-robustness and correctness caveats, not circular reductions; they do not make the derivation equivalent to its inputs. I find no significant circularity.

Assumptions & free parameters 8 free parameters · 7 assumptions · 0 invented entities

The identification claim (position, membership, period-locked variability) needs no fitted parameters. The physical characterization is the output of an eight-parameter fit whose priors and physical assumptions (tidal locking, β=0.08, atlas9 grids, <3 M☉ cutoff, cos i prior) carry the burden. The f_sd=2.71 consistency argument is not independent of the fit because it uses the fitted T_base; it is a restatement through a same-group empirical boundary. No new physical entities are introduced.

free parameters (8)
  • x1 (pulsar projected semi-major axis) = ≈0.399 lt-s (uniform prior bounded by radio value 0.398703 lt-s)
    Fitted though tightly constrained by radio timing; converts to K1≈43.3 km/s in the model.
  • orbital inclination i = 79° (+7/−13)
    Free parameter; uniform prior on cos i favors edge-on systems, so part of the high-inclination result inherits the prior.
  • companion radial-velocity semi-amplitude K2 = 433 (+40/−58) km/s
    Free parameter (uniform 10-1000 km/s); drives mass ratio q≈10 and companion mass.
  • Roche-lobe filling factor f = 0.66 (+0.05/−0.03)
    Free parameter (uniform 0-1); controls ellipsoidal amplitude; degenerate with i.
  • base temperature T_base = 7191 (+88/−85) K
    Free parameter (uniform 1000-15000 K); anchors the 'hottest redback' claim and the f_sd consistency argument.
  • irradiation temperature T_irr = 754 (+620/−525) K
    Free parameter (uniform 0-10000 K); consistent with zero, so 'mild irradiation' phrasing exceeds the formal constraint.
  • distance D = 7.3 (+0.6/−0.5) kpc
    Free parameter with Gaussian prior 8.2±0.6 kpc (Rees 1992); posterior consistent with prior within 1σ.
  • V-band extinction A_V = 0.07±0.04 mag
    Free parameter; posterior closely follows the Gaussian prior from E(g′−r′)=0.02±0.02.
assumptions (7)
  • domain assumption Tidal locking: co-rotation factor ω=1
    Set in Sect. 3.2; standard for tight spider binaries but unverified for this star; the geometric inversion depends on it.
  • domain assumption Gravity darkening β=0.08 (Lucy 1967)
    Assumes a fully convective envelope; a radiative envelope (β≈0.25) would change the ellipsoidal amplitude mapping to (i, f, K2).
  • domain assumption Icarus + atlas9 grids correctly model the distorted, heated surface
    Published code (Breton et al. 2012) used at unusual temperatures; the atmosphere grid and irradiation treatment are not independently validated here.
  • domain assumption Radio ephemeris of Pan et al. (2020) valid at HST epochs 2004-2019
    Phase folding uses P_orb=0.2008678775 d and T0 from radio timing; assumes no significant orbital evolution over 15 years.
  • domain assumption Cluster membership from HACKS proper motions (Libralato et al. 2022)
    The 1σ membership conclusion uses an external catalog; errors on μ are ~0.07 mas/yr.
  • domain assumption Neutron-star mass < 3 M☉ constraint
    Applied as a hard prior in Sect. 3.2; truncates the M1 posterior and shifts the central value.
  • ad hoc to paper Uniform prior on cos i (detectability prior)
    'The prior on the inclination is due to the fact that edge-on systems are more likely to be detected' (Sect. 3.2); an informative choice that raises the recovered i.

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Cite this review

Pith. "Pith review of Exploring the optical properties of redback pulsars: The case of J1717+4308A in the globular cluster M92." pith.science (2026). https://pith.science/paper/2IGCGXND

@misc{pith2026260722289,
  author       = {Pith},
  title        = {Pith review of: Exploring the optical properties of redback pulsars: The case of J1717+4308A in the globular cluster M92},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/2IGCGXND}},
  note         = {Machine review of arXiv:2607.22289}
}
abstract

Binary millisecond pulsars (MSPs) in globular clusters (GCs) are key for binary and stellar evolution studies under extreme conditions. The identification of their optical companion stars is instrumental in order to characterise these systems and to constrain the possible recycling mechanisms. For this work, we searched for the optical counterpart to PSR J1717+4308A (hereafter M92A) in the GC M92. To this end, we exploited a multi-epoch, multi-wavelength dataset obtained with the Hubble Space Telescope. We constructed colour--magnitude diagrams, investigated proper motions to assess cluster membership, and modelled the observed light curves. We identified an object located at only 0.02 arcsec from the nominal radio position as the likely optical companion to M92A. The star is significantly bluer than the main sequence at the same luminosity level and exhibits clear photometric variability with a periodicity in agreement with the orbital motion of the binary. The light curve displays two maxima and two minima, indicative of strong tidal distortion and only mild irradiation. Such mild irradiation is consistent with the ratio of the pulsar spin-down to the companion flux ($f_\mathrm{sd}$), which for M92A lies close to the boundary between ellipsoidal- and irradiation-dominated regimes ($f_\mathrm{sd} \approx 2.71$). From the light curve modelling we inferred the main physical properties of the companion star. The best-fit model indicates a high-inclination system with a relatively low-mass companion and a massive neutron star. With a base temperature of $\sim7200$ K, the companion ranks among the hottest redbacks known to date. This object therefore adds additional pieces to the puzzle of MSP companion properties and contributes to outlining the characteristics of redbacks across the different classes.

Figures

Figures reproduced from arXiv: 2607.22289 by the authors.

Figure 1
Figure 1. Finding charts of the optical companion star to M92A. Left panel: Original F225W image of the field around the radio position of M92A. The red cross and red circle mark the radio position of M92A and the corresponding combined optical and radio ∼ 3σ uncertainty. The companion star identified in this work is clearly visible within this region, nearly coincident with the radio position. For reference, the blue cross a… view at source ↗
Figure 2
Figure 2. Colour-magnitude diagrams of M92 in ultraviolet and optical fil￾ter combinations. In each panel, the red square marks the optical compan￾ion to M92A identified in this work, with phase-averaged magnitudes from multi-epoch photometry. The cyan tri￾angle corresponds to optical counterpart b of X-ray source CX3 (Lu et al. 2011) [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. Proper motion vector-point diagram of M92 in the cluster ref￾erence frame. All stars are shown as grey dots, while stars within ±0.5 mag of COM-M92A are highlighted in black. The 1σ, 2σ, and 3σ boundaries derived from the black dot sample are indicated by the red, blue, and grey circles, respectively. The optical companion to M92A is marked by a red square with an error bar. The light curve, which shows two minima a… view at source ↗
Figures from the paper (3 more)
Figure 4
Figure 4. Figure 4: Phase-folded HST light curves of COM-M92A in the seven different filters used in this study, overplotted with the best-fit model obtained using the Icarus code (see Section 3.2). The bottom panel reports all the residuals, colour-coded as in the above panels. The orbit…
Figure 5
Figure 5. Figure 5: Upper panel: Global light curve of the optical companion to M92A, ob￾tained from the combination of all the individual light curves shown in [PITH_FULL_IMAGE:figures/full_fig_p006_5.png]
Figure 6
Figure 6. Figure 6: Corner plot showing the poste￾rior distributions and parameter correla￾tions from the dynesty fit of the eight free parameters in the Icarus model. The marginalised distributions for incli￾nation i, radial velocity semi-amplitude K2, filling factor f , base temperature…

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Works this paper leans on

76 extracted references · 1 linked inside Pith

  1. [1]

    A., Cheng, A

    Alpar, M. A., Cheng, A. F., Ruderman, M. A., et al. 1982, Nature, 300,

    1982

  2. [2]

    2025, ApJ, 991,

    Li, Baoda, Liu, Kuo, Wang, Lin et al. 2025, ApJ, 991,

    2025

  3. [3]

    Barr, E., Dutta, A., Freire, C. C. P., Cadelano, M. et al. 2024, Science, 383, 6680 Bellini, A. & Bedin, L. R. 2009, PASP, 121,

    2024

  4. [5]

    V ., Kirichenko, A

    Bobakov, A. V ., Kirichenko, A. Y ., Zharikov, S. V ., et al. 2024, A&A, 690, A173. Bobakov, A. V ., Kirichenko, A., Zharikov, S. V ., et al. 2025, A&A, 702, A256. Breton, R. P., Rappaport, S. A., van Kerkwijk, M. H., et al. 2012, ApJ, 748,

    2024

  5. [6]

    2012, Mem

    Knigge C. 2012, Mem. Soc. Astron. Italiana, 83,

    2012

  6. [11]

    R., Dalessandro, E., et al

    Cadelano, M., Ferraro, F. R., Dalessandro, E., et al. 2022, ApJ, 941,

    2022

  7. [19]

    P., & Bridges, M

    Feroz, F., Hobson, M. P., & Bridges, M. 2009, MNRAS, 398,

    2009

  8. [25]

    2020, ApJ, 905,

    Cadelano, M., Chen, J., Pallanca, C., et al. 2020, ApJ, 905,

    2020

Show all 76 references
  1. [27]

    R., Possenti, A., et al

    Cocozza, G., Ferraro, F. R., Possenti, A., et al. 2008, ApJ, 679, L105. D’Antona, F. & Tailo, M. 2022, Astrophysics and Space Science Library, 465,

    2008

  2. [29]

    M., Lorimer, D

    Pan, Z., Ransom, S. M., Lorimer, D. R., et al. 2020, ApJ, 892, L6. Papitto, A., Ferrigno, C., Bozzo, E., et al. 2013, Nature, 501,

    2020

  3. [32]

    Harris, W. E. 1996, AJ, 112,

    1996

  4. [36]

    R., Mucciarelli, A., Lanzoni, B., et al

    Ferraro, F. R., Mucciarelli, A., Lanzoni, B., et al. 2023, Nature Communications, 14,

    2023

  5. [39]

    & Romani, R

    Kandel, D. & Romani, R. W. 2023, ApJ, 942, 1,

    2023

  6. [41]

    R., Dalessandro, E., et al

    Lanzoni, B., Ferraro, F. R., Dalessandro, E., et al. 2019, ApJ, 887,

    2019

  7. [42]

    J., Strader, J., Chomiuk, L., et al

    Swihart, S. J., Strader, J., Chomiuk, L., et al. 2022, ApJ, 941,

    2022

  8. [44]

    Lian, Yujie, Freire P. C. C., Cao, Shuo, Cadelano, Mario, Pallanca, Cristina et al. 2025, ApJ, 981, L3. Lian, Y ., Pan Z., Zhang H., Cao S. et al. 2025, ApJS, 279,

    2025

  9. [46]

    and Hut, P

    Pooley, D. and Hut, P. 2006, ApJ, 646,

    2006

  10. [47]

    Lu, T.-N., Kong, A. K. H., Verbunt, F., et al. 2011, ApJ, 736,

    2011

  11. [51]

    2022, ApJ, 934,

    Libralato, M., Bellini, A., Vesperini, E., et al. 2022, ApJ, 934,

    2022

  12. [53]

    M., Freire, P

    Cadelano, M., Ransom, S. M., Freire, P. C. C., et al. 2018, ApJ, 855,

    2018

  13. [56]

    R., Dalessandro, E., et al

    Raso, S., Ferraro, F. R., Dalessandro, E., et al. 2017, ApJ, 839, 1,

    2017

  14. [59]

    Roberts, M. S. E. 2013, Neutron Stars and Pulsars: Challenges and Opportunities after 80 years, 291,

    2013

  15. [63]

    R., et al

    Cadelano, M., Pallanca, C., Ferraro, F. R., et al. 2017, ApJ, 844,

    2017

  16. [64]

    Rees, R. F. 1992, AJ, 103,

    1992

  17. [69]

    R., Cadelano, M., et al

    Chen, J., Ferraro, F. R., Cadelano, M., et al. 2021, Nature Astronomy, 5,

    2021

  18. [70]

    & Heinke, C

    Zhao, J. & Heinke, C. O. 2022, MNRAS, 511,

    2022

  19. [72]

    2026, ApJ, 998, 1,

    Turchetta, M., Linares, M., Koljonen, K., et al. 2026, ApJ, 998, 1,

    2026

  20. [78]

    R., et al

    Sen, B., Linares, M., Kennedy, M. R., et al. 2024, ApJ, 973,

    2024

  21. [82]

    & van der Klis, M

    Wijnands, R. & van der Klis, M. 1998, Nature, 394,

    1998

  22. [84]

    M., et al

    Chen, H.-L., Chen, X., Tauris, T. M., et al. 2013, ApJ, 775,

    2013

  23. [93]

    2023, ApJ, 948,

    Chen, J., Cadelano, M., Pallanca, C., et al. 2023, ApJ, 948,

    2023

  24. [115]

    2002, ApJ, 574,

    Burderi, L., D’Antona, F., & Burgay, M. 2002, ApJ, 574,

    2002

  25. [121]

    J., Benítez, N., et al

    Sirianni, M., Jee, M. J., Benítez, N., et al. 2005, PASP, 117,

    2005

  26. [122]

    M., Ferraro, F

    Pallanca, C., Ransom, S. M., Ferraro, F. R., et al. 2014, ApJ, 795,

    2014

  27. [125]

    R., Istrate, A

    Cadelano, M., Ferraro, F. R., Istrate, A. G., et al. 2019, ApJ, 875,

    2019

  28. [127]

    & Halpern, J

    Schroeder, J. & Halpern, J. 2014, ApJ, 793, 2,

    2014

  29. [150]

    2014, ApJ, 795,

    Linares, M. 2014, ApJ, 795,

    2014

  30. [158]

    Lucy, L. B. 1967, ZAp, 65, 89 Mata Sánchez, D., Kennedy, M. R., Clark, C. J., et al. 2023, MNRAS, 520, 2,

    1967

  31. [176]

    Lewis, Evan F., Olszanski, Timothy E. E. et al. 2023, ApJ, 956,

    2023

  32. [191]

    Stetson, P. B. 1994, PASP, 106,

    1994

  33. [201]

    R., et al

    Dalessandro, E., Lanzoni, B., Ferraro, F. R., et al. 2008, ApJ, 677, 2,

    2008

  34. [250]

    Strader, J., and Swihart, S., and Chomiuk L., 2019, ApJ, 872,

    2019

  35. [337]

    R., Possenti, A., D’Amico, N

    Ferraro, F. R., Possenti, A., D’Amico, N. et al. 2001, ApJ, 561, L93–L96. Ferraro, F. R., Possenti, A., Sabbi, E., et al. 2003a, ApJ, 596, L211. Ferraro, F. R., Sills, A., Rood, R. T., et al. 2003b, ApJ, 588,

    2001

  36. [344]

    yun ., Qian, L., et al

    Yin, D., Zhang, L.-. yun ., Qian, L., et al. 2024, ApJ, 969, L7. Zhang, P., Xing, Y ., Wang, Z., et al. 2023, ApJ, 945,

    2024

  37. [380]

    Turchetta, M., Linares, M., Koljonen, K., Sen, B., 2023, MNRAS, 525,

    2023

  38. [393]

    R., Lanzoni, B., & Dalessandro, E

    Ferraro, F. R., Lanzoni, B., & Dalessandro, E. 2020, Rendiconti Lincei. Scienze Fisiche e Naturali, 31,

    2020

  39. [395]

    2006, Nested sampling for general Bayesian computation, Bayesian Anal

    Skilling, J. 2006, Nested sampling for general Bayesian computation, Bayesian Anal. 1 (4) 833 - 859, December

    2006

  40. [464]

    aa60173-26 Ferraro, F

    Article number, page 7 of 9 A&A proofs:manuscript no. aa60173-26 Ferraro, F. R., Lanzoni, B., Raso, S., et al. 2018, ApJ, 860,

    2018

  41. [517]

    2020, New A Rev., 91, 101544

    Papitto, A., Falanga, M., Hermsen, W., et al. 2020, New A Rev., 91, 101544. Paresce, F., de Marchi, G., & Ferraro, F. R. 1992, Nature, 360, 6399,

    2020

  42. [549]

    2024, Joshspeagledynesty: V2.1.4

    Koposov, S., Speagle, J., Barbary, K., et al. 2024, Joshspeagledynesty: V2.1.4. Zenodo, June 25,

    2024

  43. [553]

    W., Filippenko, A

    Kandel, D., Romani, R. W., Filippenko, A. V ., et al. 2020, ApJ, 903, 1,

    2020

  44. [653]

    R., Mucciarelli, A., et al

    Lanzoni, B., Ferraro, F. R., Mucciarelli, A., et al. 2018, ApJ, 865,

    2018

  45. [698]

    2025, A&A, 704, A261

    Ettorre, G., Dalessandro, E., Cadelano, M., Pallanca, et al. 2025, A&A, 704, A261. Ettorre, G., Dalessandro, E., Pallanca, Cadelano, M. et al. 2025, A&A, 697, A215. Ferraro, F. R., Pecci, F. F., Cacciari, C., et al. 1993, AJ, 106,

    2025

  46. [728]

    and Cheng, Z

    Bao, T., Li, Z. and Cheng, Z. al. 2023, MNRAS, 521,

    2023

  47. [768]

    R., Beccari, G., Dalessandro, E., et al

    Ferraro, F. R., Beccari, G., Dalessandro, E., et al. 2009, Nature, 462,

    2009

  48. [915]

    R., Paltrinieri, B., Rood, R

    Ferraro, F. R., Paltrinieri, B., Rood, R. T., et al. 1999, ApJ, 522,

    1999

  49. [983]

    R., D’Amico, N., Possenti, A., et al

    Ferraro, F. R., D’Amico, N., Possenti, A., et al. 2001, ApJ, 561,

    2001

  50. [989]

    R., et al

    Pallanca, C., Dalessandro, E., Ferraro, F. R., et al. 2010, ApJ, 725,

    2010

  51. [1028]

    R., Lanzoni, B., Dalessandro, E., et al

    Ferraro, F. R., Lanzoni, B., Dalessandro, E., et al. 2012, Nature, 492,

    2012

  52. [1043]

    O., Rasio, F

    Ivanova, N., Heinke, C. O., Rasio, F. A., et al. 2008, MNRAS, 386, 1,

    2008

  53. [1049]

    Speagle, J. S. 2020, MNRAS, 493,

    2020

  54. [1069]

    S., Torres, D

    De Martino, D., Phosrisom, A., Dhillon, V . S., Torres, D. F.,Coti Zelati, F., Bre- ton, R. P., Marsh, T. R., Miraval Zanon, A., Rea, N., Papitto, A. 2024, A&A, 691, A36. Dotter, A., Sarajedini, A., Anderson, J., et al. 2010, ApJ, 708,

    2024

  55. [1165]

    R., et al

    Pallanca, C., Dalessandro, E., Ferraro, F. R., et al. 2013, ApJ, 773,

    2013

  56. [1170]

    R., Cadelano, M., et al

    Chen, J., Ferraro, F. R., Cadelano, M., et al. 2022, ApJ, 934,

    2022

  57. [1419]

    G., De Vito, M

    Benvenuto, O. G., De Vito, M. A., & Horvath, J. E. 2014, ApJ, 786, L7. Benvenuto, O. G., De Vito, M. A., & Horvath, J. E. 2013, MNRAS, 433, L11. Benvenuto, O. G., De Vito, M. A., & Horvath, J. E. 2012, ApJ, 753, L33. Bhattacharya, D. & van den Heuvel, E. P. J. 1991, Phys. Rep., 203,

    2014

  58. [1487]

    O., Rasio, F

    Ivanova, N., Heinke, C. O., Rasio, F. A., et al. 2006, MNRAS, 372, 3,

    2006

  59. [1573]

    Ridolfi, A., Freire, P. C. C., Gautam, T., et al. 2022, A&A, 664, A27. Rivera-Sandoval, L. E., van den Berg, M., Heinke, C. O. et al. 2015, MNRAS, 453,

    2022

  60. [1601]

    M., Schlafly, E., Zucker, C., et al

    Green, G. M., Schlafly, E., Zucker, C., et al. 2019, ApJ, 887,

    2019

  61. [2006]

    Stetson, P. B. 1987, PASP, 99,

    1987

  62. [2023]

    A., et al

    ArXiv e-prints [arXiv:2305.09388] Turchetta, M., Sen, B., Simpson, J. A., et al. 2025, MNRAS, 538,

    2025 arXiv

  63. [2024]

    1993, Robert Kurucz CD-ROM, 13 Lanzoni, B., Ferraro, F

    Kurucz, R. 1993, Robert Kurucz CD-ROM, 13 Lanzoni, B., Ferraro, F. R., Dalessandro, E., et al. 2010, ApJ, 717,

    1993

  64. [2217]

    S, 2025, A&A, 693, A314 Nan, R., Li, D., Jin, C., et al

    Misra, D., Linares, M., and Ye, C. S, 2025, A&A, 693, A314 Nan, R., Li, D., Jin, C., et al. 2011, International Journal of Modern Physics D, 20,

    2025

  65. [2324]

    R., Paltrinieri, B., Fusi Pecci, F., et al

    Ferraro, F. R., Paltrinieri, B., Fusi Pecci, F., et al. 1997, A&A, 324,

    1997

  66. [2584]

    R., Lanzoni, B., Vesperini, E., et al

    Ferraro, F. R., Lanzoni, B., Vesperini, E., et al. 2026, Nature Communications, 17, 1,

    2026

  67. [3132]

    Skilling, J. 2004, Bayesian Inference and Maximum Entropy Methods in Sci- ence and Engineering: 24th International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering, 735,

    2004

  68. [5964]

    Article number, page 8 of 9 Jianxing Chen et al.: Redback millisecond pulsar M92A Appendix A: Dataset summary Table A.1.Summary of the multi-epoch HST dataset used in this work. Proposal ID Observation date Filter Exposure time WFC3 GO-15173 2019 June 28 F225W 800s×2, 805s×3, ...

    2019

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