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arxiv: 2604.21621 · v1 · submitted 2026-04-23 · 🌌 astro-ph.SR

VLTI-GRAVITY measurements of cool evolved stars: II. Pulsation properties and mass-loss process of the Mira star R Car and the red supergiant VX Sgr

D. Jadlovsk\'y , M. Wittkowski , A. Chiavassa , K. Kravchenko , B. Freytag , S. H\"ofner , J. Krti\v{c}ka , C. Paladini
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G. Rau M. Bro\v{z} T. Granzer M. Weber
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Pith reviewed 2026-05-08 14:05 UTC · model grok-4.3

classification 🌌 astro-ph.SR
keywords evolved starsMira variablesred supergiantsstellar mass losspulsationsinterferometric observationsatmospheric layerspulsation modes
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The pith

Long-term observations indicate steady mass loss in Mira stars driven by stable pulsations and episodic mass loss in red supergiants driven by pulsation mode changes.

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

The paper reports on extensive VLTI-GRAVITY observations spanning seven years of the Mira star R Car and the red supergiant VX Sgr to connect their variability to mass loss. The data reveal variable photospheric and atmospheric radii that peak near light minima, with CO layers extending to 1.3-2.2 times the stellar radius, matching hydrodynamic simulations. Both stars show a 13 percent pulsation amplitude in fundamental mode during active phases, but VX Sgr also has a quiescent phase with smaller amplitude and an extreme mass loss event marked by shocks and layer expansions. These findings support the idea that Mira mass loss is steady and tied to consistent fundamental mode pulsation, whereas red supergiant mass loss is dominated by extreme events from pulsation mode changes.

Core claim

The central claim is that the mass-loss process differs between the two types of stars based on their pulsation properties: R Car exhibits stable fundamental-mode pulsation with amplitude 13% of its 280 solar radius photosphere, enabling steady mass loss, whereas VX Sgr with its ~1500 solar radius shows the same amplitude in fundamental mode only during active cycles and switches to low-amplitude first-overtone pulsation in quiescent cycles, during which it experiences an extreme mass-loss event similar to Betelgeuse's with layer expansions and emission lines indicating shocks.

What carries the argument

Time-series VLTI-GRAVITY interferometry measuring variable angular diameters of the photosphere and molecular layers, related to light curves via phase shifts and validated against CO5BOLD simulations.

If this is right

  • The mass loss of Mira stars like R Car proceeds at a steady rate linked to their persistent large-amplitude fundamental mode pulsations.
  • Red supergiants like VX Sgr experience mass loss primarily through intense, short-lived events that coincide with shifts in their pulsation mode.
  • When in the fundamental mode, both Miras and red supergiants can exhibit comparable relative pulsation amplitudes of about 13% of the photospheric radius.
  • Extreme events in red supergiants involve the temporary extension of molecular layers to twice the photospheric radius accompanied by shock signatures in emission lines.

Where Pith is reading between the lines

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

  • If this pattern holds, stellar evolution models for AGB and RSG phases should treat pulsation mode stability as a key parameter for predicting total mass lost over a star's lifetime.
  • Monitoring other red supergiants for mode changes could help predict the timing of their next major mass-loss episodes.
  • The similarity in active pulsation amplitudes suggests that the fundamental mode is particularly effective at levitating material in both classes of stars.

Load-bearing premise

The phase shifts between the maxima in radius and the minima in the light curve, together with the measured extensions of the atmospheric layers, are taken to establish the causal mechanism connecting the pulsation mode to the mass-loss process.

What would settle it

A red supergiant observed to undergo an extreme mass-loss event while remaining in a stable fundamental-mode pulsation without mode transition, or a mode transition without an associated mass-loss event.

Figures

Figures reproduced from arXiv: 2604.21621 by A. Chiavassa, B. Freytag, C. Paladini, D. Jadlovsk\'y, G. Rau, J. Krti\v{c}ka, K. Kravchenko, M. Bro\v{z}, M. Weber, M. Wittkowski, S. H\"ofner, T. Granzer.

Figure 1
Figure 1. Figure 1: Examples of the calibrated flux (averaged for four ATs), the squared visibility amplitude |V| 2 (averaged for both polarizations), and the closure phase as a function of the wavelength for both our targets at representative dates. The flux was calibrated using the spectral trans￾fer function of the calibrators. The |V| 2 dataset consists of six projected baselines B, while closure phase consists of four ba… view at source ↗
Figure 2
Figure 2. Figure 2: Variability of the flux (calibrated using the spectral transfer function) for all our observations. The spectra were divided by mean flux in the continuum region (2.22 − 2.28 µm). Spectral regions analyzed in this work are highlighted. Upper panel: R Car, vertically shifted and ordered by ϕvis. Colored based on phase (ϕvis = 0 corresponds to brightness maximum). Lower panel: The same, but for VX Sgr, verti… view at source ↗
Figure 3
Figure 3. Figure 3: Same as view at source ↗
Figure 5
Figure 5. Figure 5: Comparison between the determined wavelength-dependent an￾gular diameters during min (red) and max (blue) photospheric radius for our two targets. The observation dates are denoted in the legend. Con￾version to the physical size (right y-axis) was done using the adopted distances from view at source ↗
Figure 6
Figure 6. Figure 6: Upper panel: Variability of R Car based on the visual mag￾nitude from AAVSO data and the angular diameters determined with VLTI-GRAVITY (binned in 2-week intervals). For clarity, we merge CO bands θCO(2−0) with θCO(3−1) and θCO(4−2) with θCO(5−3). Different col￾ors correspond to the continuum and to regions of the extended atmo￾sphere. Lower panel: Phase diagram of brightness and diameter vari￾ability. Sol… view at source ↗
Figure 7
Figure 7. Figure 7: Same as view at source ↗
Figure 8
Figure 8. Figure 8: Lomb-Scargle (LS) normalized periodograms that we calculated for R Car (upper panels) and VX Sgr (lower panels). In the panels with diameters, we also highlight the False Alarm Probability (FAP, Vander￾Plas 2018), for levels of 1% and 10% (gray and black dashed lines) determined with astropy, which is one of the standard ways to judge peak significance. From our layers, usually only θcont and θTi i,Sc i re… view at source ↗
Figure 9
Figure 9. Figure 9: Intensity profiles and intensity maps for snapshots 122 (t = 19.18 yrs) and 131 (t = 20.61 yrs) of the AGB model st28gm05n057. Left panels: Intensity profiles, plotted for all wavelengths in the GRAVITY spectral range, with 3 representative wavelengths highlighted. Right panels: Intensity maps for two selected representative wavelengths are shown, 2.250 µm (continuum) and 2.384 µm (band head of 12C 16O, 5-… view at source ↗
Figure 11
Figure 11. Figure 11: Same as view at source ↗
Figure 12
Figure 12. Figure 12: Upper panel: The selected part of the synthetic bolometric light curve (black line, smoothed), including the computed angular diameters for 28 snapshots of our AGB model. The base value of the angular di￾ameter was set to be similar to that of R Car. Rosseland radius was con￾verted to angular diameter using the distance of R Car (vertically shifted by -2 mas). Lower panel: Phase diagram, showing the phase… view at source ↗
Figure 13
Figure 13. Figure 13: Upper panel: Radial velocity measurements and FWHM of CCF for VX Sgr from the STELLA telescope compared to V and vi￾sual light curves from AAVSO. The data show similar behavior to that of Betelgeuse (Kravchenko et al. 2021; Jadlovský et al. 2024), namely the double-shock feature in the FWHM plot before the likely mass￾loss event. Lower panel: Hα for selected STELLA spectra, showing the emergence of the em… view at source ↗
Figure 14
Figure 14. Figure 14: Schematic overview of our results for R Car and VX Sgr, show￾ing average atmospheric extension and diameter variations (arrows), scaled by the continuum (photopsheric) radius θcont. For VX Sgr, the properties based on the active cycle are shown. For the Mira-type AGB star R Car with regular variabil￾ity, we found that our determined angular diameters of pho￾tospheric and near-photospheric layers are phase… view at source ↗
read the original abstract

The mass-loss process of red supergiant (RSG) and asymptotic giant branch (AGB) stars and its relation to variability is poorly constrained. We study two evolved stars, the Mira-type AGB star R Car and the extreme RSG VX Sgr. Our sample comprises 54 VLTI-GRAVITY snapshots taken over 7 years, being the largest VLTI time-series dataset to date. We determine the angular diameter as a function of time. The radii of the photosphere ($R_{\star}$) and atomic atmospheric layers are variable and relate to the light curve with phase shifts, showing a maximum radius near visual brightness minima. The more extended CO layers show longer, irregular periods and maximum extensions of $\sim 1.3-1.7 \: R_{\star}$ for R Car, and of $\sim 1.5-2.2 \: R_{\star}$ for VX Sgr. Comparison with CO5BOLD simulations revealed a similar behavior. Furthermore, during 2020-2021, VX Sgr exhibited an extreme mass-loss event similar to that of Betelgeuse, preceded by two strong shocks and culminating with the extreme expansion of H$_2$O and CO layers, both up to $\sim 2.2 \: R_{\star}$. During this event, we detected Brackett $\gamma$ and Balmer emission lines, both of which are signatures of a shock propagating through the atmosphere. The Mira R Car showed a photospheric radius $R_{\star} = 280 \pm 25 \: \rm R_\odot$, with a fundamental mode (FM) pulsation amplitude $\sim13 \%$ of $R_{\star} $. During its active cycle, the RSG VX Sgr showed $R_{\star} = 1556 \pm 110 \: \rm R_\odot$ with FM amplitude $ \sim13 \%$ of $R_{\star} $, the same as R Car. During its quiescent cycle, it showed $R_{\star}= 1456 \pm 108 \: \rm R_\odot$ and low-amplitude pulsations near the first overtone, only $\sim4 \%$ of $R_{\star} $. This supports a steady mass loss for Miras related to stable, large-amplitude FM pulsation, whereas the mass-loss process for RSGs may be dominated by extreme events connected to changes in the pulsation mode.

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 reports VLTI-GRAVITY interferometric observations of the Mira R Car and RSG VX Sgr across 54 epochs over 7 years. It derives time-variable angular diameters, photospheric radii (R_star = 280 ± 25 R_⊙ for R Car; 1556 ± 110 R_⊙ active and 1456 ± 108 R_⊙ quiescent for VX Sgr), and extensions of CO/H2O layers (up to 1.3–2.2 R_star). Radius maxima occur near light-curve minima with phase shifts; R Car and active VX Sgr show ~13% fundamental-mode (FM) pulsation amplitudes while quiescent VX Sgr shows ~4% first-overtone amplitude. A 2020–2021 extreme expansion event in VX Sgr is described, accompanied by shocks, Brackett-γ and Balmer emission, and layer extensions to ~2.2 R_star, compared to CO5BOLD simulations. The authors conclude that steady mass loss in Miras is linked to stable large-amplitude FM pulsation, whereas RSG mass loss is dominated by extreme events connected to pulsation-mode changes.

Significance. If the interpretive links hold, this supplies the largest VLTI time-series dataset for evolved stars, direct angular-diameter measurements with quoted uncertainties, empirical phase relations between radius and light curves, and the first detailed interferometric view of a Betelgeuse-like event in an RSG. The equal FM amplitudes (~13% of R_star) in the active phases of both stars and the simulation comparisons provide concrete tests for atmospheric models. These data constrain the timing and extent of molecular-layer dynamics even if the causal mapping to mass-loss regimes remains partly interpretive.

major comments (3)
  1. [Abstract] Abstract: the claim that the observations 'support a steady mass loss for Miras related to stable, large-amplitude FM pulsation, whereas the mass-loss process for RSGs may be dominated by extreme events connected to changes in the pulsation mode' is not backed by direct Ṁ measurements or quantitative comparisons of mass-loss rates between quiescent and active phases; the inference rests on radius variations, one 2020–2021 event, and layer extensions without excluding alternative drivers such as convection or dust nucleation.
  2. [Abstract] Abstract and conclusions: with only two stars observed, the distinction between 'steady' Mira and 'extreme-event' RSG regimes is based on a single expansion event in VX Sgr; generalization requires explicit discussion of how the observed correlations (phase shifts, 1.3–2.2 R_star extensions) would falsify the interpretation or be produced by other atmospheric processes.
  3. [Abstract] The reported phase shifts between radius maxima and light-curve minima, together with CO/H2O layer extensions, demonstrate correlation with pulsation but do not establish the causal mechanism linking mode changes to the mass-loss process; no quantitative test (e.g., predicted Ṁ from the observed extensions) is provided to distinguish this from coincidental or multi-driver scenarios.
minor comments (2)
  1. The abstract mixes observational results with interpretive conclusions; separating the two more explicitly would improve clarity for readers.
  2. Notation for photospheric radius (R_star) and layer extensions should be defined once in the main text with consistent use of uncertainties.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the constructive and detailed comments. We address each major point below and indicate the revisions planned for the manuscript.

read point-by-point responses

  1. Referee: [Abstract] Abstract: the claim that the observations 'support a steady mass loss for Miras related to stable, large-amplitude FM pulsation, whereas the mass-loss process for RSGs may be dominated by extreme events connected to changes in the pulsation mode' is not backed by direct Ṁ measurements or quantitative comparisons of mass-loss rates between quiescent and active phases; the inference rests on radius variations, one 2020–2021 event, and layer extensions without excluding alternative drivers such as convection or dust nucleation.

    Authors: We acknowledge that the manuscript contains no direct Ṁ measurements and that the mass-loss interpretation is inferential. The abstract claims rest on the time-series correlations between FM pulsation amplitude, radius maxima near light minima, and molecular-layer extensions, together with the match to CO5BOLD simulations and the shock signatures observed during the VX Sgr event. We will revise the abstract to replace 'support' with 'are consistent with' and add an explicit paragraph in the discussion section addressing alternative drivers (convection, dust nucleation) and noting that the data constrain but do not exclude them. revision: partial

  2. Referee: [Abstract] Abstract and conclusions: with only two stars observed, the distinction between 'steady' Mira and 'extreme-event' RSG regimes is based on a single expansion event in VX Sgr; generalization requires explicit discussion of how the observed correlations (phase shifts, 1.3–2.2 R_star extensions) would falsify the interpretation or be produced by other atmospheric processes.

    Authors: We agree that the sample size and the reliance on a single extreme event limit generalization. In the revised conclusions we will add a dedicated limitations paragraph that (i) states the distinction is provisional, (ii) outlines how the reported phase shifts and 1.3–2.2 R_star extensions could be falsified (e.g., absence of similar extensions during future mode changes), and (iii) discusses how other atmospheric processes could produce comparable signatures. revision: yes

  3. Referee: [Abstract] The reported phase shifts between radius maxima and light-curve minima, together with CO/H2O layer extensions, demonstrate correlation with pulsation but do not establish the causal mechanism linking mode changes to the mass-loss process; no quantitative test (e.g., predicted Ṁ from the observed extensions) is provided to distinguish this from coincidental or multi-driver scenarios.

    Authors: The phase shifts and extensions are presented as correlations whose timing coincides with light-curve minima and, in VX Sgr, with detected shocks. We will add clarifying text stating that no quantitative Ṁ prediction is derived from the extensions and that the causal link remains interpretive. We will also discuss the possibility of coincidental or multi-driver scenarios and note that a full quantitative test would require hydrodynamic modeling beyond the scope of this observational paper. revision: partial

Circularity Check

0 steps flagged

Empirical radius and phase measurements from interferometry do not reduce to self-defined or fitted inputs

full rationale

The paper's core results consist of direct determinations of angular diameters versus time from VLTI-GRAVITY visibilities, followed by conversion to physical radii and measurement of phase offsets relative to the light curve. These quantities are extracted from the data rather than predicted from prior fitted parameters within the same equations. The interpretive claim that Mira mass loss is steady and tied to stable FM pulsation while RSG mass loss is event-driven is presented as a qualitative inference from the observed layer extensions and one expansion episode, not as a quantitative prediction that loops back to the input visibilities or fitted radii by construction. No self-citation is invoked as a uniqueness theorem or load-bearing premise for the central distinction, and the comparison to CO5BOLD simulations is external. The derivation chain therefore remains self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claims rest on direct interferometric measurements of angular diameters and their time variation, plus comparison to existing CO5BOLD simulations; no new free parameters, ad-hoc axioms, or invented entities are introduced beyond standard assumptions of stellar atmosphere modeling and data reduction.

axioms (1)
  • standard math Standard VLTI visibility-to-angular-diameter conversion and atmospheric layer identification procedures
    Invoked to derive photospheric and CO/H2O radii from the 54 snapshots.

pith-pipeline@v0.9.0 · 5844 in / 1259 out tokens · 53026 ms · 2026-05-08T14:05:25.658719+00:00 · methodology

discussion (0)

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Works this paper leans on

95 extracted references · 3 canonical work pages · 1 internal anchor

  1. [1]

    2023, A&A, 669, A49

    Ahmad, A., Freytag, B., & Höfner, S. 2023, A&A, 669, A49

    2023

  2. [2]

    2025, A&A, 699, A148

    Ahmad, A., Freytag, B., & Höfner, S. 2025, A&A, 699, A148

    2025

  3. [3]

    2015, A&A, 575, A50

    Arroyo-Torres, B., Wittkowski, M., Chiavassa, A., et al. 2015, A&A, 575, A50

    2015

  4. [4]

    M., & Hauschildt, P

    Arroyo-Torres, B., Wittkowski, M., Marcaide, J. M., & Hauschildt, P. H. 2013, A&A, 554, A76 Astropy Collaboration, Price-Whelan, A. M., Lim, P. L., et al. 2022, ApJ, 935, 167

    2013

  5. [5]

    K., Creech-Eakman, M

    Baylis-Aguirre, D. K., Creech-Eakman, M. J., & van Belle, G. T. 2024, Galaxies, 12, 72

    2024

  6. [6]

    2019, A&A, 626, A100

    Bladh, S., Liljegren, S., Höfner, S., Aringer, B., & Marigo, P. 2019, A&A, 626, A100

    2019

  7. [7]

    & Wolf, E

    Born, M. & Wolf, E. 1980, Principles of Optics Electromagnetic Theory of Prop- agation, Interference and Diffraction of Light

    1980

  8. [8]

    2017, VizieR Online Data Cat- alog: JMMC Stellar Diameters Catalogue - JSDC

    Bourges, L., Mella, G., Lafrasse, S., et al. 2017, VizieR Online Data Cat- alog: JMMC Stellar Diameters Catalogue - JSDC. Version 2 (Bourges+, 2017), VizieR On-line Data Catalog: II/346. Originally published in: 2014ASPC..485..223B

    2017

  9. [9]

    A., Laplace, E., Schneider, F

    Bronner, V . A., Laplace, E., Schneider, F. R. N., & Podsiadlowski, P. 2025, A&A, 703, A61

    2025

  10. [10]

    2007, Chinese J

    Chen, X., Shen, Z.-Q., & Xu, Y . 2007, Chinese J. Astron. Astrophys., 7, 531

    2007

  11. [11]

    Chiavassa, A., Kravchenko, K., & Goldberg, J. A. 2024, Living Reviews in Com- putational Astrophysics, 10, 2

    2024

  12. [12]

    2022, A&A, 658, A185

    Chiavassa, A., Kravchenko, K., Montargès, M., et al. 2022, A&A, 658, A185

    2022

  13. [13]

    2010, A&A, 511, A51

    Chiavassa, A., Lacour, S., Millour, F., et al. 2010, A&A, 511, A51

    2010

  14. [14]

    2009, A&A, 506, 1351

    Chiavassa, A., Plez, B., Josselin, E., & Freytag, B. 2009, A&A, 506, 1351

    2009

  15. [15]

    B., Wittkowski, M., Chiavassa, A., et al

    Climent, J. B., Wittkowski, M., Chiavassa, A., et al. 2020, A&A, 635, A160

    2020

  16. [16]

    & Plez, B

    Davies, B. & Plez, B. 2021, MNRAS, 508, 5757

    2021

  17. [17]

    J., & Booth, A

    Davis, J., Tango, W. J., & Booth, A. J. 2000, Monthly Notices of the Royal Astronomical Society, 318, 387 De Beck, E., Decin, L., de Koter, A., et al. 2010, A&A, 523, A18

    2000

  18. [18]

    2025, A&A, 703, L23

    Decin, L., Vermeulen, O., Esseldeurs, M., et al. 2025, A&A, 703, L23

    2025

  19. [19]

    E., Mairs, S., Scicluna, P., et al

    Dharmawardena, T. E., Mairs, S., Scicluna, P., et al. 2020, ApJ, 897, L9

    2020

  20. [20]

    K., Cristofari, P

    Dupree, A. K., Cristofari, P. I., MacLeod, M., & Kravchenko, K. 2026, ApJ, 998, 50

    2026

  21. [21]

    K., Strassmeier, K

    Dupree, A. K., Strassmeier, K. G., Calderwood, T., et al. 2022, ApJ, 936, 18

    2022

  22. [22]

    K., Strassmeier, K

    Dupree, A. K., Strassmeier, K. G., Matthews, L. D., et al. 2020, ApJ, 899, 68

    2020

  23. [23]

    2011, A&A, 535, A12

    Fabas, N., Lèbre, A., & Gillet, D. 2011, A&A, 535, A12

    2011

  24. [24]

    P., Mocz, P., et al

    Farag, E., Bellinger, E. P., Mocz, P., et al. 2026, arXiv e-prints, arXiv:2603.15766

    work page arXiv 2026

  25. [25]

    W., Lang, D., & Goodman, J

    Foreman-Mackey, D., Hogg, D. W., Lang, D., & Goodman, J. 2013, PASP, 125, 306

    2013

  26. [26]

    W., Wood, P

    Fox, M. W., Wood, P. R., & Dopita, M. A. 1984, ApJ, 286, 337

    1984

  27. [27]

    J., et al

    Fransson, C., Ergon, M., Challis, P. J., et al. 2014, ApJ, 797, 118

    2014

  28. [28]

    & Höfner, S

    Freytag, B. & Höfner, S. 2023, A&A, 669, A155

    2023

  29. [29]

    2024, A&A, 692, A223

    Freytag, B., Höfner, S., Aringer, B., & Chiavassa, A. 2024, A&A, 692, A223

    2024

  30. [30]

    2017, A&A, 600, A137

    Freytag, B., Liljegren, S., & Höfner, S. 2017, A&A, 600, A137

    2017

  31. [31]

    2012, Journal of Computational Physics, 231, 919 Gaia Collaboration, Brown, A

    Freytag, B., Steffen, M., Ludwig, H.-G., et al. 2012, Journal of Computational Physics, 231, 919 Gaia Collaboration, Brown, A. G. A., Vallenari, A., et al. 2021, A&A, 649, A1

    2012

  32. [32]

    2020, A&A, 644, A139

    Gail, H.-P., Tamanai, A., Pucci, A., & Dohmen, R. 2020, A&A, 644, A139

    2020

  33. [33]

    A., Jiang, Y .-F., & Bildsten, L

    Goldberg, J. A., Jiang, Y .-F., & Bildsten, L. 2022, ApJ, 929, 156

    2022

  34. [34]

    A., Joyce, M., & Molnár, L

    Goldberg, J. A., Joyce, M., & Molnár, L. 2024, ApJ, 977, 35 González-Torà, G., Wittkowski, M., Davies, B., & Plez, B. 2024, A&A, 683, A19 González-Torà, G., Wittkowski, M., Davies, B., Plez, B., & Kravchenko, K. 2023, A&A, 669, A76 GRA VITY Collaboration, Abuter, R., Accardo, M., et al. 2017, A&A, 602, A94 GRA VITY Collaboration, Garcia Lopez, R., Natta, ...

    2024

  35. [35]

    Groenewegen, M. A. T., Baas, F., Blommaert, J. A. D. L., et al. 1999, A&AS, 140, 197

    1999

  36. [36]

    G., Almendros-Abad, V ., Lovell, J

    Guarcello, M. G., Almendros-Abad, V ., Lovell, J. B., et al. 2025, A&A, 693, A120

    2025

  37. [37]

    2020, The As- tronomer’s Telegram, 13512, 1

    Guinan, E., Wasatonic, R., Calderwood, T., & Carona, D. 2020, The As- tronomer’s Telegram, 13512, 1

    2020

  38. [38]

    2008, A&A, 486, 951

    Gustafsson, B., Edvardsson, B., Eriksson, K., et al. 2008, A&A, 486, 951

    2008

  39. [39]

    2009, A&A, 508, 923 Höfner, S., Bladh, S., Aringer, B., & Eriksson, K

    Haubois, X., Perrin, G., Lacour, S., et al. 2009, A&A, 508, 923 Höfner, S., Bladh, S., Aringer, B., & Eriksson, K. 2022, A&A, 657, A109 Höfner, S. & Freytag, B. 2019, A&A, 623, A158 Höfner, S. & Olofsson, H. 2018, A&A Rev., 26, 1

    2009

  40. [40]

    B., Ciardi, D

    Howell, S. B., Ciardi, D. R., Clark, C. A., et al. 2025, ApJ, 988, L47

    2025

  41. [41]

    Humphreys, R. M. & Jones, T. J. 2022, AJ, 163, 103

    2022

  42. [42]

    J., Scholz, M., & Wood, P

    Ireland, M. J., Scholz, M., & Wood, P. R. 2008, MNRAS, 391, 1994

    2008

  43. [43]

    J., Scholz, M., & Wood, P

    Ireland, M. J., Scholz, M., & Wood, P. R. 2011b, MNRAS, 418, 114 Jacobson-Galán, W. V ., Dessart, L., Jones, D. O., et al. 2022, ApJ, 924, 15 Jadlovský, D., Granzer, T., Weber, M., et al. 2024, A&A, 685, A124 Jadlovský, D., Molnár, L., Ercolino, A., et al. 2025, arXiv e-prints, arXiv:2509.25168

    work page internal anchor Pith review arXiv 2022

  44. [44]

    2013, A&A, 560, A91

    Jones, A., Noll, S., Kausch, W., Szyszka, C., & Kimeswenger, S. 2013, A&A, 560, A91

    2013

  45. [45]

    & Plez, B

    Josselin, E. & Plez, B. 2007, A&A, 469, 671

    2007

  46. [46]

    2020, ApJ, 902, 63

    Joyce, M., Leung, S.-C., Molnár, L., et al. 2020, ApJ, 902, 63

    2020

  47. [47]

    L., Szabó, G

    Kiss, L. L., Szabó, G. M., & Bedding, T. R. 2006, MNRAS, 372, 1721

    2006

  48. [48]

    2025, A&A, 694, A208

    Klement, R., Rivinius, T., Baade, D., et al. 2025, A&A, 694, A208

    2025

  49. [49]

    2019, A&A, 631, A108

    Kluska, J., Van Winckel, H., Hillen, M., et al. 2019, A&A, 631, A108

    2019

  50. [50]

    2019, A&A, 632, A28

    Kravchenko, K., Chiavassa, A., Van Eck, S., et al. 2019, A&A, 632, A28

    2019

  51. [51]

    2021, A&A, 650, L17

    Kravchenko, K., Jorissen, A., Van Eck, S., et al. 2021, A&A, 650, L17

    2021

  52. [52]

    2018, A&A, 610, A29

    Kravchenko, K., Van Eck, S., Chiavassa, A., et al. 2018, A&A, 610, A29

    2018

  53. [53]

    2020, A&A, 642, A235 Lançon, A., Hauschildt, P

    Kravchenko, K., Wittkowski, M., Jorissen, A., et al. 2020, A&A, 642, A235 Lançon, A., Hauschildt, P. H., Ladjal, D., & Mouhcine, M. 2007, A&A, 468, 205 Lançon, A. & Wood, P. R. 2000, A&AS, 146, 217

    2020

  54. [54]

    A., Schneider, F

    Laplace, E., Bronner, V . A., Schneider, F. R. N., & Podsiadlowski, P. 2026, ApJ, 998, L40

    2026

  55. [55]

    Lawson, P. R., ed. 2000, Principles of Long Baseline Stellar Interferometry

    2000

  56. [56]

    Levesque, E. M. 2017, Astrophysics of Red Supergiants, 2514-3433 (IOP Pub- lishing)

    2017

  57. [57]

    Levesque, E. M. & Massey, P. 2020, ApJ, 891, L37

    2020

  58. [58]

    Lockwood, G. W. & Wing, R. F. 1982, MNRAS, 198, 385

    1982

  59. [59]

    2025, arXiv e-prints, arXiv:2510.14875, doi: 10.48550/arXiv.2510.14875

    Ma, J.-Z., Justham, S., Pakmor, R., et al. 2025, arXiv e-prints, arXiv:2510.14875

    work page arXiv 2025

  60. [60]

    D., Dupree, A., & Loeb, A

    MacLeod, M., Antoni, A., Huang, C. D., Dupree, A., & Loeb, A. 2023, ApJ, 956, 27

    2023

  61. [61]

    J., et al

    MacLeod, M., Blunt, S., De Rosa, R. J., et al. 2025, ApJ, 978, 50

    2025

  62. [62]

    & Josselin, E

    Mauron, N. & Josselin, E. 2011, A&A, 526, A156

    2011

  63. [63]

    A., & Boyer, M

    McDonald, I., Zijlstra, A. A., & Boyer, M. L. 2012, MNRAS, 427, 343

    2012

  64. [64]

    2002, ApJ, 579, 446 Montargès, M., Cannon, E., Lagadec, E., et al

    Mennesson, B., Perrin, G., Chagnon, G., et al. 2002, ApJ, 579, 446 Montargès, M., Cannon, E., Lagadec, E., et al. 2021, Nature, 594, 365 Muñoz-Sanchez, G., Kalitsounaki, M., de Wit, S., et al. 2026, Nature Astronomy

    2002

  65. [65]

    2012, A&A, 543, A92 O’Grady, A., Moriya, T

    Noll, S., Kausch, W., Barden, M., et al. 2012, A&A, 543, A92 O’Grady, A., Moriya, T. J., Renzo, M., & Vigna-Gómez, A. 2026, in Encyclope- dia of Astrophysics, V olume 3, V ol. 3, 336–357

    2012

  66. [66]

    2005, A&A, 429, 1057

    Ohnaka, K., Bergeat, J., Driebe, T., et al. 2005, A&A, 429, 1057

    2005

  67. [67]

    2018, Nature, 553, 310

    Paladini, C., Baron, F., Jorissen, A., et al. 2018, Nature, 553, 310

    2018

  68. [68]

    T., Mennesson, B., et al

    Perrin, G., Ridgway, S. T., Mennesson, B., et al. 2004, A&A, 426, 279

    2004

  69. [69]

    T., et al

    Perrin, G., Verhoelst, T., Ridgway, S. T., et al. 2007, A&A, 474, 599

    2007

  70. [70]

    G., Malbet, F., Weigelt, G., et al

    Petrov, R. G., Malbet, F., Weigelt, G., et al. 2007, A&A, 464, 1 Rosales-Guzmán, A., Sanchez-Bermudez, J., Paladini, C., et al. 2023, A&A, 674, A62 Rosales-Guzmán, A., Sanchez-Bermudez, J., Paladini, C., et al. 2024, A&A, 688, A124 Samus’, N. N., Kazarovets, E. V ., Durlevich, O. V ., Kireeva, N. N., & Pas- tukhova, E. N. 2017, Astronomy Reports, 61, 80

    2007

  71. [71]

    & Wood, P

    Scholz, M. & Wood, P. R. 2000, A&A, 362, 1065

    2000

  72. [72]

    2022, MNRAS, 512, 1091

    Scicluna, P., Kemper, F., McDonald, I., et al. 2022, MNRAS, 512, 1091

    2022

  73. [73]

    M., Tomida, K., White, C

    Stone, J. M., Tomida, K., White, C. J., & Felker, K. G. 2020, ApJS, 249, 4

    2020

  74. [74]

    G., Granzer, T., Weber, M., et al

    Strassmeier, K. G., Granzer, T., Weber, M., et al. 2004, Astronomische Nachrichten, 325, 527

    2004

  75. [75]

    & Shigeyama, T

    Suzuki, A. & Shigeyama, T. 2025, MNRAS, 543, 3929

    2025

  76. [76]

    M., Dorda, R., Negueruela, I., & Marfil, E

    Tabernero, H. M., Dorda, R., Negueruela, I., & Marfil, E. 2021, A&A, 646, A98

    2021

  77. [77]

    2013, PASJ, 65, 60

    Takeuti, M., Nakagawa, A., Kurayama, T., & Honma, M. 2013, PASJ, 65, 60

    2013

  78. [78]

    2022, Nature Astronomy, 6, 930

    Taniguchi, D., Yamazaki, K., & Uno, S. 2022, Nature Astronomy, 6, 930

    2022

  79. [79]

    R., Creech-Eakman, M

    Thompson, R. R., Creech-Eakman, M. J., & van Belle, G. T. 2002, ApJ, 577, 447

    2002

  80. [80]

    R., Creech-Eakman, M

    Thompson, R. R., Creech-Eakman, M. J., & van Belle, G. T. 2003, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 4838, Interferometry for Optical Astronomy II, ed. W. A. Traub, 221–234

    2003

Showing first 80 references.