pith. sign in

arxiv: 2606.17559 · v1 · pith:2RL5575Anew · submitted 2026-06-16 · 🌌 astro-ph.SR

Characterizing Orbital Parameters of Hot Subdwarf Binaries with Multiple Spectroscopic Surveys

Pith reviewed 2026-06-26 23:21 UTC · model grok-4.3

classification 🌌 astro-ph.SR
keywords hot subdwarfsbinary starsorbital parameterscommon-envelope evolutionradial velocitylight curvesGaia
0
0 comments X

The pith

Hot subdwarf binaries mostly follow the mass-period distribution of post-common-envelope systems.

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

The work analyzes atmospheric and orbital parameters for 157 hot subdwarfs drawn from Gaia and multiple spectroscopic surveys. Atmospheric values come from a convolutional neural network plus template matching, while orbital solutions for 23 binaries are obtained by fitting radial-velocity curves and light curves. Eleven of the orbital solutions are new. The resulting mass-period diagram for the sample overlaps strongly with the distribution already known for post-common-envelope binaries. This overlap is presented as evidence that common-envelope evolution is the dominant channel that produces these hot-subdwarf systems.

Core claim

Most of these systems share a similar mass--period distribution with that of post-common-envelope binaries, supporting a common-envelope origin.

What carries the argument

Mass-period distribution constructed from orbital solutions derived by simultaneous radial-velocity and light-curve fitting.

Load-bearing premise

The observed similarity between the derived mass-period distribution and that of known post-common-envelope binaries is not dominated by selection effects or by alternative formation channels that happen to occupy the same region of parameter space.

What would settle it

A statistically significant excess of hot-subdwarf binaries lying outside the post-common-envelope mass-period locus once detection probabilities and survey selection functions are explicitly modeled.

Figures

Figures reproduced from arXiv: 2606.17559 by Buhui Lv, Chuanjie Zheng, Jifeng Liu, Song Wang, Xiaohong Yang, Xinlin Zhao, Yangyang Dong, Zhenxin Lei.

Figure 1
Figure 1. Figure 1: A summary flowchart illustrating the workflow used in this paper. nature of the companion and possible formation mech￾anisms. Finally, a summary is given in Section 6. 2. SAMPLE SELECTION AND DATA REDUCTION 2.1. Initial sample In this study, we used the HSD catalogue (includ￾ing 6616 known HSDs and 61585 candidates) based on Gaia EDR3 (Gaia Collaboration et al. 2021; Culpan [PITH_FULL_IMAGE:figures/full_f… view at source ↗
Figure 2
Figure 2. Figure 2: Position of our sample on the HR diagram. Red and blue markers correspond to systems with η < 2.5 and η > 2.5, respectively (see Section 4.1). Circles represent known HSDs, whereas stars indicate HSD candidates from Culpan et al. (2022). The gray points are plotted for a com￾parison, which are from Gaia EDR3 with distances d < 100 pc, Gmag between 4–16 mag, and galactic latitudes |b| > 40 deg. and GALAH ar… view at source ↗
Figure 3
Figure 3. Figure 3: Example schematic of LRS spectral fitting based on the CNN method. The black lines indicate the observed LRS, while the red lines are the best-fit templates. Two methods were adopted to estimate the radius of HSDs in this work. In the first method, we determined the radii of HSDs following (Lei et al. 2023a): R2 d 2 = f(λ) F(λ) , (1) where F(λ) is the model flux at the stellar surface and f(λ) is the obser… view at source ↗
Figure 4
Figure 4. Figure 4: Top row: Comparison of atmospheric parameters derived from the CNN method and the template-matching method. Bottom row:Comparison of the derived atmospheric parameters between this work and previous studies. where σ is the the Stefan-Boltzmann constant. L⊙ is so￾lar bolometric luminosity (3.828×1033 erg/s) and M⊙ is solar bolometric magnitude (4.74 mag). Here, mλ is the apparent magnitude of three bands (G… view at source ↗
Figure 5
Figure 5. Figure 5: Left panel: The Kiel diagram for our sample. The dashed black lines show the ZAEHB and TAEHB sequences for [Fe/H]=-1.48 from Dorman et al. (1993), while the black solid line indicates the helium main sequence (HeMS) from Paczyński (1971). Right panel: Teff−log(nHe/nH) diagram. The red dashed line denotes the solar He abundance (e.g., log(nHe/nH) = −1). The dotted and solid lines represent the linear regres… view at source ↗
Figure 6
Figure 6. Figure 6: Comparison of the radii derived from the two methods with the results from Lei et al. (2023a). The red and blue dots represent the radii from the first and second methods, respectively. and single-star systems, while others (Breedt et al. 2017) used the threshold of η > 2.5. In our sample, 73 systems have η > 2.5 and 66 systems have η > 4. Given that our sample has more RV observations, we adopted η > 2.5 … view at source ↗
Figure 7
Figure 7. Figure 7: Distribution of the radius and mass of HSDs from atmospheric parameters derived using the CNN method. The black and red histograms correspond to the radius and mass estimates derived from the first method and the second method, respectively. The blue and green lines represent the median, along with the 16th and 84th percentiles, of the radius and mass estimates derived from the first method. obvious eclips… view at source ↗
Figure 8
Figure 8. Figure 8: The joint LC and RV fitting for the 10 reflection binaries in our binary sample. The red dots represent TESS LC binned into 100 phase intervals. The red and green circles indicate the RV data from LAMOST MRS and LRS, respectively. The black lines are the best-fitting models derived from PHOEBE. Given that the LCs yield robust orbital periods, only RV data with uncertainties smaller than 15 km/s are used in… view at source ↗
Figure 9
Figure 9. Figure 9: Top row: Comparison of orbital parameters for systems in [PITH_FULL_IMAGE:figures/full_fig_p015_9.png] view at source ↗
Figure 12
Figure 12. Figure 12: Comparison of our sample with PCEBs in M1– Period diagram. The dashed line represents the evolutionary track predicted for binaries undergoing stable mass transfer (Rappaport et al. 1995). PCEB samples (Zorotovic et al. 2010; Yamaguchi et al. 2024a) in the M1–Period diagram. As is shown in [PITH_FULL_IMAGE:figures/full_fig_p016_12.png] view at source ↗
Figure 11
Figure 11. Figure 11: A comparison of orbital periods and the mass of the companion for different binaries in this work and lit￾erature. 0 0 0 0 0   M M  0⊙ 00 0 0 0       [PITH_FULL_IMAGE:figures/full_fig_p016_11.png] view at source ↗
read the original abstract

Hot subdwarfs (HSDs) provide critical insights into the physical mechanisms governing binary evolution. In this work, we conduct a systematic analysis of 157 HSDs, selected from Gaia EDR3 and characterized using multi-survey spectroscopic data. Atmospheric parameters of these HSDs are derived via a convolutional neural network (CNN) method and template-matching method. Based on the atmospheric parameters from CNN method, these HSDs exhibit a median mass of $0.45^{+0.19}_{-0.17} M_{\odot}$ and radius of $0.18^{+0.04}_{-0.05} R_{\odot}$, consistent with earlier work. Orbital parameters of 23 systems are determined through the fitting of radial velocity data and light curves, with 11 of them being new solutions. We find that reflection-dominated binaries typically have periods longer than 0.1 d and host low-mass main-sequence companions ($\sim$ 0.2 $M_{\odot}$) with rotation-inflated radii. In contrast, binaries including an HSD and a white dwarf show very short periods ($P < 0.2$ d), with the closest systems hosting more massive white dwarfs. Most of these systems share a similar mass--period distribution with that of post-common-envelope binaries, supporting a common-envelope origin.

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

3 major / 2 minor

Summary. The paper analyzes 157 hot subdwarfs from Gaia EDR3, deriving atmospheric parameters via CNN and template-matching methods and reporting median mass 0.45 M_⊙ and radius 0.18 R_⊙. It determines orbital parameters for 23 binaries (11 new) via multi-survey RV and light-curve fitting, distinguishes reflection-dominated systems (P > 0.1 d, low-mass MS companions) from WD companions (P < 0.2 d), and claims that most systems share a mass-period distribution with known post-common-envelope binaries, supporting a common-envelope origin.

Significance. If the mass-period similarity holds after accounting for selection, the addition of 11 new orbital solutions and the period-companion distinctions would strengthen observational constraints on hot subdwarf binary formation channels by extending the sample of systems with measured parameters.

major comments (3)
  1. [Abstract] Abstract: the central claim that 'Most of these systems share a similar mass--period distribution with that of post-common-envelope binaries, supporting a common-envelope origin' is load-bearing for the paper's interpretation but rests on a direct comparison to an external literature benchmark without applying a quantitative selection function to the Gaia EDR3 parent catalog of 157 HSDs or forward-modeling the RV detection threshold through the multi-survey pipeline.
  2. [Atmospheric parameters] Atmospheric parameters section: no quantitative error budgets, goodness-of-fit statistics, or assessment of systematic offsets between CNN and template-matching results are reported for the median mass (0.45^{+0.19}_{-0.17} M_⊙) and radius (0.18^{+0.04}_{-0.05} R_⊙), which underpin the mass-period distribution used for the formation-channel conclusion.
  3. [Orbital parameters] Orbital parameters for the 23 systems: the manuscript provides no goodness-of-fit statistics or full covariance/error budgets for the fitted periods and companion masses, limiting evaluation of the claimed period-companion distinctions (reflection vs. WD) and the robustness of the mass-period overlap.
minor comments (2)
  1. [Abstract] The abstract does not specify whether the quoted median mass and radius are taken from the CNN or template-matching results.
  2. A summary table of the 23 orbital solutions (periods, companion types, fit metrics) would improve clarity of the period-regime distinctions.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the constructive report and the recommendation for major revision. We address each major comment below and will revise the manuscript to incorporate quantitative assessments, error budgets, and goodness-of-fit statistics where these were previously omitted.

read point-by-point responses
  1. Referee: [Abstract] Abstract: the central claim that 'Most of these systems share a similar mass--period distribution with that of post-common-envelope binaries, supporting a common-envelope origin' is load-bearing for the paper's interpretation but rests on a direct comparison to an external literature benchmark without applying a quantitative selection function to the Gaia EDR3 parent catalog of 157 HSDs or forward-modeling the RV detection threshold through the multi-survey pipeline.

    Authors: We acknowledge that the mass-period comparison is currently qualitative and that a quantitative selection function or forward-modeling of detection thresholds would strengthen the claim. The manuscript's primary contribution is the addition of 11 new orbital solutions and the period-companion distinctions; the formation-channel interpretation is presented as supportive rather than definitive. In revision we will add an explicit discussion of Gaia EDR3 selection effects and the multi-survey RV sensitivity limits, including a simple forward-model estimate of detection completeness. revision: yes

  2. Referee: [Atmospheric parameters] Atmospheric parameters section: no quantitative error budgets, goodness-of-fit statistics, or assessment of systematic offsets between CNN and template-matching results are reported for the median mass (0.45^{+0.19}_{-0.17} M_⊙) and radius (0.18^{+0.04}_{-0.05} R_⊙), which underpin the mass-period distribution used for the formation-channel conclusion.

    Authors: The reported medians and uncertainties come from the CNN-derived parameters for the full sample of 157 objects; the template-matching results were used only for cross-checks. We agree that quantitative error budgets, goodness-of-fit metrics, and a direct comparison of systematic offsets between the two methods are needed. These will be added to the revised Atmospheric parameters section, including tables of fit statistics and a quantitative offset analysis. revision: yes

  3. Referee: [Orbital parameters] Orbital parameters for the 23 systems: the manuscript provides no goodness-of-fit statistics or full covariance/error budgets for the fitted periods and companion masses, limiting evaluation of the claimed period-companion distinctions (reflection vs. WD) and the robustness of the mass-period overlap.

    Authors: The orbital solutions were obtained via joint RV and light-curve fitting, but the manuscript indeed omitted the full covariance matrices and goodness-of-fit diagnostics. We will include these (reduced chi-squared values, residual plots, and parameter covariance tables) for all 23 systems in the revised Orbital parameters section to allow readers to assess the robustness of the period-companion distinctions and the mass-period distribution. revision: yes

Circularity Check

0 steps flagged

No circularity: orbital parameters from direct RV/light-curve fits; mass-period comparison uses external literature benchmarks

full rationale

The paper determines orbital parameters for 23 systems (11 new) by fitting observed radial velocity data and light curves. Atmospheric parameters come from CNN and template-matching applied to spectroscopic data. The central claim compares the resulting mass-period distribution to post-common-envelope binaries drawn from independent external literature. No step reduces a derived quantity to a fitted input by construction, invokes a self-citation as the sole justification for a uniqueness theorem, or renames a known result as a new derivation. The comparison is presented as an empirical match to an external reference distribution rather than a self-defined or internally fitted prediction. The derivation chain is therefore self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The central claims rest on two standard domain assumptions in stellar spectroscopy and binary orbit determination; no free parameters, new physical entities, or ad-hoc axioms are introduced in the abstract.

axioms (2)
  • domain assumption The CNN and template-matching procedures return unbiased atmospheric parameters (Teff, log g) from the available spectra.
    These parameters are converted to masses and radii that underpin the median values and the subsequent orbital analysis.
  • domain assumption Fits to radial-velocity and light-curve data yield reliable orbital periods and companion masses without significant aliasing or systematic bias.
    These fitted quantities are used to construct the mass-period distribution that is compared with post-common-envelope binaries.

pith-pipeline@v0.9.1-grok · 5793 in / 1496 out tokens · 45406 ms · 2026-06-26T23:21:10.732266+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

110 extracted references · 101 canonical work pages · 10 internal anchors

  1. [1]

    , keywords =

    Almeida, L. A., Jablonski, F., Tello, J., & Rodrigues, C. V. 2012, MNRAS, 423, 478, doi: 10.1111/j.1365-2966.2012.20891.x

  2. [2]

    2021, The Astronomical Journal, 161, 147, doi: 10.3847/1538-3881/abd806

    Demleitner, M., & Andrae, R. 2021, AJ, 161, 147, doi: 10.3847/1538-3881/abd806

  3. [3]

    2015, A&A, 577, A42, doi: 10.1051/0004-6361/201425481

    Baraffe, I., Homeier, D., Allard, F., & Chabrier, G. 2015, A&A, 577, A42, doi: 10.1051/0004-6361/201425481

  4. [4]

    N., Kilkenny, D., Drechsel, H., et al

    Barlow, B. N., Kilkenny, D., Drechsel, H., et al. 2013, MNRAS, 430, 22, doi: 10.1093/mnras/sts271

  5. [5]

    V., & Deller, J

    Beuermann, K., Dreizler, S., Hessman, F. V., & Deller, J. 2012, A&A, 543, A138, doi: 10.1051/0004-6361/201219391

  6. [6]

    Robust constraints on neutrino properties

    Bloemen, S., Marsh, T. R., Østensen, R. H., et al. 2011, MNRAS, 410, 1787, doi: 10.1111/j.1365-2966.2010.17559.x 18 Zhao et al

  7. [7]

    R., et al

    Breedt, E., Steeghs, D., Marsh, T. R., et al. 2017, MNRAS, 468, 2910, doi: 10.1093/mnras/stx430

  8. [8]

    E., et al

    Buder, S., Kos, J., Wang, X. E., et al. 2025, PASA, 42, e051, doi: 10.1017/pasa.2025.26

  9. [9]

    2008, A&A, 489, 377, doi: 10.1051/0004-6361:200809907

    Charpinet, S., Van Grootel, V., Reese, D., et al. 2008, A&A, 489, 377, doi: 10.1051/0004-6361:200809907

  10. [10]

    E., Kochoska, A., Hey, D., et al

    Conroy, K. E., Kochoska, A., Hey, D., et al. 2020, ApJS, 250, 34, doi: 10.3847/1538-4365/abb4e2

  11. [11]

    Maxted, P. F. L., & Heber, U. 2011, MNRAS, 415, 1381, doi: 10.1111/j.1365-2966.2011.18786.x

  12. [12]

    2022, A&A, 662, A40, doi: 10.1051/0004-6361/202243337

    Culpan, R., Geier, S., Reindl, N., et al. 2022, A&A, 662, A40, doi: 10.1051/0004-6361/202243337

  13. [13]

    , keywords =

    Davis, P. J., Kolb, U., & Willems, B. 2010, MNRAS, 403, 179, doi: 10.1111/j.1365-2966.2009.16138.x

  14. [14]

    2024, A&A, 686, A25, doi: 10.1051/0004-6361/202348319

    Dawson, H., Geier, S., Heber, U., et al. 2024, A&A, 686, A25, doi: 10.1051/0004-6361/202348319

  15. [15]

    2026, A&A, 707, A6, doi: 10.1051/0004-6361/202558123

    Dawson, H., Dorsch, M., Geier, S., et al. 2026, A&A, 707, A6, doi: 10.1051/0004-6361/202558123

  16. [16]

    2015, ApJ, 808, 179, doi: 10.1088/0004-637X/808/2/179

    Derekas, A., Németh, P., Southworth, J., et al. 2015, ApJ, 808, 179, doi: 10.1088/0004-637X/808/2/179

  17. [17]

    T., & O’Connell, R

    Dorman, B., Rood, R. T., & O’Connell, R. W. 1993, ApJ, 419, 596, doi: 10.1086/173511

  18. [18]

    2001, A&A, 379, 893, doi: 10.1051/0004-6361:20011376

    Drechsel, H., Heber, U., Napiwotzki, R., et al. 2001, A&A, 379, 893, doi: 10.1051/0004-6361:20011376

  19. [19]

    2005, A&A, 442, 1023, doi: 10.1051/0004-6361:20053267

    Edelmann, H., Heber, U., Altmann, M., Karl, C., & Lisker, T. 2005, A&A, 442, 1023, doi: 10.1051/0004-6361:20053267

  20. [20]

    2003, A&A, 400, 939, doi: 10.1051/0004-6361:20030135

    Edelmann, H., Heber, U., Hagen, H.-J., et al. 2003, A&A, 400, 939, doi: 10.1051/0004-6361:20030135

  21. [21]

    Q., Green, E

    For, B. Q., Green, E. M., Fontaine, G., et al. 2010, ApJ, 708, 253, doi: 10.1088/0004-637X/708/1/253 Gaia Collaboration. 2020, VizieR Online Data Catalog: Gaia EDR3 (Gaia Collaboration, 2020), VizieR On-line Data Catalog: I/350. Originally published in: 2021A&A...649A...1G, doi: 10.26093/cds/vizier.1350 Gaia Collaboration, Brown, A. G. A., Vallenari, A., ...

  22. [22]

    2008, A&A, 477, L13, doi: 10.1051/0004-6361:20078797

    Geier, S., Nesslinger, S., Heber, U., et al. 2008, A&A, 477, L13, doi: 10.1051/0004-6361:20078797

  23. [23]

    Geier, S., Maxted, P. F. L., Napiwotzki, R., et al. 2011a, A&A, 526, A39, doi: 10.1051/0004-6361/201015794

  24. [24]

    2011b, A&A, 530, A28, doi: 10.1051/0004-6361/201015316

    Geier, S., Hirsch, H., Tillich, A., et al. 2011b, A&A, 530, A28, doi: 10.1051/0004-6361/201015316

  25. [25]

    2011c, ApJL, 731, L22, doi: 10.1088/2041-8205/731/2/L22

    Geier, S., Schaffenroth, V., Drechsel, H., et al. 2011c, ApJL, 731, L22, doi: 10.1088/2041-8205/731/2/L22

  26. [26]

    The MUCHFUSS project - Searching for the most massive companions to hot subdwarf stars in close binaries and finding the least massive ones

    Geier, S., Schaffenroth, V., Hirsch, H., et al. 2012, in Astronomical Society of the Pacific Conference Series, Vol. 452, Fifth Meeting on Hot Subdwarf Stars and Related Objects, ed. D. Kilkenny, C. S. Jeffery, & C. Koen, 129, doi: 10.48550/arXiv.1112.2922

  27. [27]

    R., Wang, B., et al

    Geier, S., Marsh, T. R., Wang, B., et al. 2013, A&A, 554, A54, doi: 10.1051/0004-6361/201321395

  28. [28]

    2015, A&A, 577, A26, doi: 10.1051/0004-6361/201525666

    Geier, S., Kupfer, T., Heber, U., et al. 2015, A&A, 577, A26, doi: 10.1051/0004-6361/201525666

  29. [29]

    2024, A&A, 690, A368, doi: 10.1051/0004-6361/202450778

    Geier, S., Heber, U., Irrgang, A., et al. 2024, A&A, 690, A368, doi: 10.1051/0004-6361/202450778

  30. [30]

    M., Schlafly, E

    Green, G. M., Schlafly, E. F., Finkbeiner, D. P., et al. 2015, ApJ, 810, 25, doi: 10.1088/0004-637X/810/1/25

  31. [31]

    D., & Jeffery, C

    Hall, P. D., & Jeffery, C. S. 2016, MNRAS, 463, 2756, doi: 10.1093/mnras/stw2188

  32. [32]

    , eprint =

    Han, Z., & Podsiadlowski, P. 2004, MNRAS, 350, 1301, doi: 10.1111/j.1365-2966.2004.07713.x

  33. [33]

    Han, Z., Podsiadlowski, P., Maxted, P. F. L., & Marsh, T. R. 2003, MNRAS, 341, 669, doi: 10.1046/j.1365-8711.2003.06451.x

  34. [34]

    Han, Z., Podsiadlowski, P., Maxted, P. F. L., Marsh, T. R., & Ivanova, N. 2002, MNRAS, 336, 449, doi: 10.1046/j.1365-8711.2002.05752.x

  35. [35]

    2020, Research in Astronomy and Astrophysics, 20, 161, doi: 10.1088/1674-4527/20/10/161

    Han, Z.-W., Ge, H.-W., Chen, X.-F., & Chen, H.-L. 2020, Research in Astronomy and Astrophysics, 20, 161, doi: 10.1088/1674-4527/20/10/161

  36. [36]

    2025, A&A, 693, A121, doi: 10.1051/0004-6361/202451411

    He, R., Meng, X., Lei, Z., Yan, H., & Lan, S. 2025, A&A, 693, A121, doi: 10.1051/0004-6361/202451411

  37. [37]

    2026, in Encyclopedia of Astrophysics, Volume 2, Vol

    Heber, U. 2026, in Encyclopedia of Astrophysics, Volume 2, Vol. 2, 488–507, doi: 10.1016/B978-0-443-21439-4.00043-2

  38. [38]

    2026, A&A, 708, A115, doi: 10.1051/0004-6361/202558636

    Heber, U., Kufleitner, L., Dorsch, M., et al. 2026, A&A, 708, A115, doi: 10.1051/0004-6361/202558636

  39. [39]

    E., Pablo, H., et al

    Horvat, M., Conroy, K. E., Pablo, H., et al. 2018, ApJS, 237, 26, doi: 10.3847/1538-4365/aacd0f

  40. [40]

    Kruk, J. W. 2015, A&A, 578, A125, doi: 10.1051/0004-6361/201526229

  41. [41]

    2019, Squeeze-and-Excitation Networks

    Hu, J., Shen, L., Albanie, S., Sun, G., & Wu, E. 2019, Squeeze-and-Excitation Networks. https://arxiv.org/abs/1709.01507

  42. [42]

    A brief introductory guide to TLUSTY and SYNSPEC

    Hubeny, I., & Lanz, T. 2017, arXiv e-prints, arXiv:1706.01859, doi: 10.48550/arXiv.1706.01859

  43. [43]

    Spectrophotometry and period analysis of the sdB eclipsing binary HW Virginis

    Kiss, L. L., Csák, B., Szatmáry, K., Furész, G., & Sziládi, K. 2000, A&A, 364, 199, doi: 10.48550/arXiv.astro-ph/0010446

  44. [44]

    L., Tucker, R

    Kraus, A. L., Tucker, R. A., Thompson, M. I., Craine, E. R., & Hillenbrand, L. A. 2011, ApJ, 728, 48, doi: 10.1088/0004-637X/728/1/48 19

  45. [45]

    2015, A&A, 576, A44, doi: 10.1051/0004-6361/201425213

    Kupfer, T., Geier, S., Heber, U., et al. 2015, A&A, 576, A44, doi: 10.1051/0004-6361/201425213

  46. [46]

    2017a, ApJ, 851, 28, doi: 10.3847/1538-4357/aa9522

    Kupfer, T., Ramsay, G., van Roestel, J., et al. 2017a, ApJ, 851, 28, doi: 10.3847/1538-4357/aa9522

  47. [47]

    2017b, ApJ, 835, 131, doi: 10.3847/1538-4357/835/2/131

    Kupfer, T., van Roestel, J., Brooks, J., et al. 2017b, ApJ, 835, 131, doi: 10.3847/1538-4357/835/2/131

  48. [48]

    B., Marsh, T

    Kupfer, T., Bauer, E. B., Marsh, T. R., et al. 2020a, ApJ, 891, 45, doi: 10.3847/1538-4357/ab72ff

  49. [49]

    B., Burdge, K

    Kupfer, T., Bauer, E. B., Burdge, K. B., et al. 2020b, ApJL, 898, L25, doi: 10.3847/2041-8213/aba3c2

  50. [50]

    B., van Roestel, J., et al

    Kupfer, T., Bauer, E. B., van Roestel, J., et al. 2022, ApJL, 925, L12, doi: 10.3847/2041-8213/ac48f1

  51. [51]

    2007, ApJS, 169, 83, doi: 10.1086/511270

    Lanz, T., & Hubeny, I. 2007, ApJS, 169, 83, doi: 10.1086/511270

  52. [52]

    2011, ApJ, 733, 100, doi: 10.1088/0004-637X/733/2/100

    Latour, M., Fontaine, G., Brassard, P., et al. 2011, ApJ, 733, 100, doi: 10.1088/0004-637X/733/2/100

  53. [53]

    M., Dorsch, M., et al

    Latour, M., Green, E. M., Dorsch, M., et al. 2026, A&A, 705, A248, doi: 10.1051/0004-6361/202557314

  54. [54]

    2025, Deep learning-driven atmospheric parameter prediction for hot subdwarf stars with synthetic and observed spectra

    Lei, Z., Dong, Y., Kou, B., et al. 2025, Deep learning-driven atmospheric parameter prediction for hot subdwarf stars with synthetic and observed spectra. https://arxiv.org/abs/2512.20185

  55. [55]

    2023a, ApJ, 953, 122, doi: 10.3847/1538-4357/ace25e

    Lei, Z., He, R., Németh, P., et al. 2023a, ApJ, 953, 122, doi: 10.3847/1538-4357/ace25e

  56. [56]

    2018, ApJ, 868, 70, doi: 10.3847/1538-4357/aae82b —

    Lei, Z., Zhao, J., Németh, P., & Zhao, G. 2018, ApJ, 868, 70, doi: 10.3847/1538-4357/aae82b —. 2019, ApJ, 881, 135, doi: 10.3847/1538-4357/ab2edc —. 2020, ApJ, 889, 117, doi: 10.3847/1538-4357/ab660a

  57. [57]

    2023b, ApJ, 942, 109, doi: 10.3847/1538-4357/aca542 Lightkurve Collaboration, Cardoso, J

    Lei, Z., He, R., Németh, P., et al. 2023b, ApJ, 942, 109, doi: 10.3847/1538-4357/aca542 Lightkurve Collaboration, Cardoso, J. V. d. M., Hedges, C., et al. 2018, Lightkurve: Kepler and TESS time series analysis in Python, Astrophysics Source Code Library. http://ascl.net/1812.013

  58. [58]

    2020, arXiv e-prints, arXiv:2005.07210

    Liu, C., Fu, J., Shi, J., et al. 2020, arXiv e-prints, arXiv:2005.07210. https://arxiv.org/abs/2005.07210

  59. [59]

    K., & Han, Z

    Liu, Z.-W., Röpke, F. K., & Han, Z. 2023, Research in Astronomy and Astrophysics, 23, 082001, doi: 10.1088/1674-4527/acd89e

  60. [60]

    L., Zhao, Y.-H., Zhao, G., et al

    Luo, A. L., Zhao, Y.-H., Zhao, G., et al. 2015, Research in Astronomy and Astrophysics, 15, 1095, doi: 10.1088/1674-4527/15/8/002

  61. [61]

    2025, Science China

    Luo, C., Li, J., Zheng, C., et al. 2025, Science China

  62. [62]

    Physics, Mechanics, and Astronomy, 68, 269511, doi: 10.1007/s11433-024-2630-x

  63. [63]

    2021, ApJS, 256, 28, doi: 10.3847/1538-4365/ac11f6

    Luo, Y., Németh, P., Wang, K., Wang, X., & Han, Z. 2021, ApJS, 256, 28, doi: 10.3847/1538-4365/ac11f6

  64. [64]

    Maxted, P. F. L., Heber, U., Marsh, T. R., & North, R. C. 2001, MNRAS, 326, 1391, doi: 10.1111/j.1365-2966.2001.04714.x

  65. [65]

    Maxted, P. F. L., Marsh, T. R., Heber, U., et al. 2002, MNRAS, 333, 231, doi: 10.1046/j.1365-8711.2002.05406.x

  66. [66]

    Maxted, P. F. L., Marsh, T. R., & Moran, C. K. J. 2000, MNRAS, 319, 305, doi: 10.1046/j.1365-8711.2000.03840.x

  67. [67]

    Wide sdB binaries. I. Orbital and atmospheric parameters

    Molina, F., Vos, J., Bobrick, A., & Vučković, M. 2026, arXiv e-prints, arXiv:2602.05008, doi: 10.48550/arXiv.2602.05008

  68. [68]

    Morales-Rueda, L., Maxted, P. F. L., Marsh, T. R., North, R. C., & Heber, U. 2003, MNRAS, 338, 752, doi: 10.1046/j.1365-8711.2003.06088.x

  69. [69]

    Morton, T. D. 2015, isochrones: Stellar model grid package. http://ascl.net/1503.010 Németh, P., Kawka, A., & Vennes, S. 2012, MNRAS, 427, 2180, doi: 10.1111/j.1365-2966.2012.22009.x

  70. [70]

    Synthetic spectra for O and B type subdwarf stars

    Nemeth, P., Östensen, R., Tremblay, P., & Hubeny, I. 2014, in Astronomical Society of the Pacific Conference Series, Vol. 481, 6th Meeting on Hot Subdwarf Stars and Related Objects, ed. V. van Grootel, E. Green, G. Fontaine, & S. Charpinet, 95, doi: 10.48550/arXiv.1308.0252 Østensen, R., Oreiro, R., Drechsel, H., et al. 2007, in Astronomical Society of th...

  71. [71]

    G., Rebassa-Mansergas, A., Schreiber, M

    Parsons, S. G., Rebassa-Mansergas, A., Schreiber, M. R., et al. 2016, MNRAS, 463, 2125, doi: 10.1093/mnras/stw2143

  72. [72]

    G., Gänsicke, B

    Parsons, S. G., Gänsicke, B. T., Marsh, T. R., et al. 2018, MNRAS, 481, 1083, doi: 10.1093/mnras/sty2345

  73. [73]

    2021, Nature Astronomy, 5, 1052, doi: 10.1038/s41550-021-01413-0

    Pelisoli, I., Neunteufel, P., Geier, S., et al. 2021, Nature Astronomy, 5, 1052, doi: 10.1038/s41550-021-01413-0

  74. [74]

    Hot Subdwarfs in Binaries as the Source of the Far-UV Excess in Elliptical Galaxies

    Podsiadlowski, P., Han, Z., Lynas-Gray, A. E., & Brown, D. 2008, in Astronomical Society of the Pacific Conference Series, Vol. 392, Hot Subdwarf Stars and Related Objects, ed. U. Heber, C. S. Jeffery, & R. Napiwotzki, 15, doi: 10.48550/arXiv.0808.0574 20 Zhao et al

  75. [75]

    2007, in Astronomical Society of the Pacific Conference Series, Vol

    Polubek, G., Pigulski, A., Baran, A., & Udalski, A. 2007, in Astronomical Society of the Pacific Conference Series, Vol. 372, 15th European Workshop on White Dwarfs, ed. R. Napiwotzki & M. R. Burleigh, 487

  76. [76]

    H., & Rybicki, G

    Press, W. H., & Rybicki, G. B. 1989, ApJ, 338, 277, doi: 10.1086/167197

  77. [77]

    M., et al

    Pritzkuleit, M., Dorsch, M., Miller Bertolami, M. M., et al. 2026, A&A, 710, A99, doi: 10.1051/0004-6361/202659703 Prša, A., Conroy, K. E., Horvat, M., et al. 2016, ApJS, 227, 29, doi: 10.3847/1538-4365/227/2/29

  78. [78]

    A., Kupfer, T., et al

    Ramsay, G., Woudt, P. A., Kupfer, T., et al. 2022, MNRAS, 513, 2215, doi: 10.1093/mnras/stac1000

  79. [79]

    C., Di Stefano, R., & Han, Z

    Rappaport, S., Podsiadlowski, P., Joss, P. C., Di Stefano, R., & Han, Z. 1995, MNRAS, 273, 731, doi: 10.1093/mnras/273.3.731

  80. [80]

    K., Barlow, B

    Ratzloff, J. K., Barlow, B. N., Kupfer, T., et al. 2019, ApJ, 883, 51, doi: 10.3847/1538-4357/ab3727

Showing first 80 references.