YSES 2b is a background star: Differential astrometric M-dwarf measurements in time

Alexander Bohn; Arthur Vigan; Christian Ginski; Emily Rickman; Eric Mamajek; Gilles Otten; Jason Wang; Jens Kammerer; Mariangela Bonavita; Markus Janson

REVIEW 4 major objections 4 minor 55 references

YSES 2b is a background star: Differential astrometric M-dwarf measurements in time

T0 review · 4 major / 4 minor · reviewed 2026-08-04 · deepseek-v4-flash

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Pith's one-line read YSES 2b is a distant M-dwarf star, not an exoplanet

desk verdict YSES 2b is a background M-dwarf—the SED says so, but the astrometric evidence is weaker than the abstract claims. read the letter →

arxiv 2509.09504 v1 pith:YB2MSRTE submitted 2025-09-11 astro-ph.EP astro-ph.SR

Matthew Kenworthy , Tomas Stolker , Jens Kammerer , William Balmer , Arthur Vigan , Sylvestre Lacour , Gilles Otten , Eric Mamajek

show 8 more authors

Christian Ginski Mathias Nowak Steven Martos Jason Wang Emily Rickman Markus Janson Alexander Bohn Mariangela Bonavita

This is my paper

classification astro-ph.EPastro-ph.SR

keywords YSES2bdirectimagingbackgroundstarMdwarfdifferentialastrometryparallaxcommonpropermotionexoplanetconfirmation

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

This paper sets out to settle the nature of YSES 2b, a faint companion of the young star YSES 2 that had been announced as a directly imaged exoplanet. Combining new and archival SPHERE imaging with four epochs of GRAVITY astrometry, the paper tracks the object's annual parallax and concludes it is a background late-type M-dwarf star roughly 2.5 kiloparsecs behind YSES 2, not a bound substellar companion. The M dwarf moves at about 300 km/s in the plane of the sky and lies in the Sagittarius spiral arm, seen through significant dust extinction. The result matters because it shows that common proper motion tests can be fooled by background stars whose apparent motion mimics that of the target, and that a parallax-based test can settle companionship in months rather than years. If correct, it removes YSES 2b from the exoplanet census and strengthens the case for using differential astrometry to vet future direct-imaging candidates.

What carries the argument

The key mechanism is the annual parallax helix in relative astrometry: a background object traces a small helical path against the foreground star's frame because of Earth's orbit, whereas a bound companion shares the primary's parallax. The authors fit the data with a background astrometric model that samples parallax, coordinates, and proper motions, generating helical background tracks, and use nested sampling to compare these against the measured positions. The GRAVITY instrument provides the sub-milliarcsecond differential astrometry needed to detect the tiny parallactic excursion of the background candidate over four epochs spanning more than a year.

What would settle it

A future astrometric epoch (or a re-analysis of the existing GRAVITY data) that yields a relative position of YSES 2b deviating significantly from the fitted background track—say, by more than the reported uncertainties—would falsify the background-star interpretation and would require revisiting the bound-orbit hypothesis. Alternatively, a high-resolution K-band spectrum showing molecular features inconsistent with a ~3100 K M-dwarf SED would weaken the current classification.

Watch

Extended reading notes

Core claim

The central claim is that YSES 2b is not a planet but a background M-dwarf star. The decisive evidence is the object's measured annual parallax: the relative astrometry across eight epochs is best fit by a background model with a parallax of 0.41 milliarcseconds and proper motion of about -25 mas/yr in RA and +4 mas/yr in Dec. That parallax places the object at roughly 2.5 kpc, far behind the 109 pc foreground star, ruling out a bound orbit. The spectral energy distribution, from GRAVITY spectra and SPHERE photometry, independently favors a ~3100 K star with radius ~0.28 solar radii and extinction A_V ~4.

Load-bearing premise

The conclusion rests on the accuracy of the GRAVITY differential astrometry, especially the swap-binary phase referencing used for calibration; if those measurements carry unmodeled systematics or underestimated error bars, the inferred background parallax and proper motion—and thus the rejection of a bound orbit—could be biased.

Editorial extensions

If this is right

YSES 2b is no longer a directly imaged exoplanet; any prior constraints on planet formation or orbital dynamics drawn from it must be discarded.
Common proper motion alone is insufficient to confirm gravitational binding; background stars with matching apparent motion can masquerade as companions for years.
A parallax test (common vs non-common) can confirm or refute companionship within months for nearby primaries and sub-milliarcsecond astrometry, provided observations are spread across the year.
Systems with only one candidate companion are the most vulnerable to background contamination; the chance of multiple unrelated sources mimicking the same proper motion is much lower.
Future astrometric monitoring should schedule observations near the start and end of the target's yearly visibility window to efficiently detect or exclude background objects.

Reading between the lines

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

The parallax-based vetting method demonstrated here could be applied retroactively to other unconfirmed direct-imaging candidates that currently have only two-epoch proper motion data, potentially revealing additional background impostors in the published exoplanet census.
Refining the M dwarf's astrometric parameters would yield a precise space velocity; combined with its location in the Sagittarius arm, this could constrain Galactic kinematics or the interstellar dust distribution along that line of sight.
The reduced chi-square of about 3.0 for the background fit hints that the formal error bars on the GRAVITY astrometry may be underestimated; if so, other background-object identifications using the same technique might require inflated uncertainties before robust conclusions are drawn.
Survey scheduling tools could incorporate a simple 'parallax season' heuristic—observe candidates near the points of the target's yearly visibility when the Earth's orbital baseline is largest—as a cheap insurance policy against background contamination.

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Editorial analysis

A structured set of objections, weighed in public.

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

Desk Editor's Note

read the letter

Colleague,

The paper is right: YSES 2b is a background M-dwarf, not a planet. The K-band spectrum and SED fit are the real evidence—a 3100 K, reddened star can't be a 6 Mjup planet. The astrometric fit is good supporting material, but the parallax is too weak to carry the argument on its own.

What's new: it overturns a published exoplanet detection, and it shows how the NCPx test with GRAVITY can settle these cases quickly. The code and data are on GitHub with a showyourwork repo, which is good. They also admit the proper motion match is a near-coincidence, which is honest.

Soft spots in proportion: the reduced chi-square of 3.02 on the background fit is never discussed. That's a red flag. The other one is the missing Keplerian fit—you can't reject a bound orbit without showing its chi-square or a model comparison. The paper leaves that out.

The GRAVITY systematics worry is real, but not crippling. The four GRAVITY epochs sit in two seasons, so a swap-binary zero-point that drifts with season could mimic a parallax. There's no null test on a known companion and no cross-check with the 2022 SPHERE point. Still, the SED is independent of that. The parallax is only ~1.5 sigma, so the abstract oversells it as 'the main discriminant.' The SED is.

There's also a mismatch in the SED parameters between sections (3110 K vs 3065 K, Av 4.1 vs 2.7). Probably one is a posterior median and the other a best fit, but it reads as sloppy.

For peer review: yes, send it out. The result matters, the method is useful, and the reproducibility is above average. But the authors should add the Keplerian comparison, explain the chi-square, and address the GRAVITY calibration. Then it's a clean accept.

Audience: direct imaging and binary-star astrometry people. I'd bring it to a reading group.

Referee Report

4 major / 4 minor

Summary. The manuscript reports new SPHERE and GRAVITY astrometry of the candidate companion YSES 2b and tests whether it is a bound substellar companion or a background star. Using the background-model code `backtracks`, the authors fit an unbound object with its own parallax and proper motion to eight astrometric epochs spanning 2018–2025. The fit yields a parallax of 0.41 mas (distance ≈2.5 kpc), proper motion of (pmRA, pmDec) ≈ (−25.4, +4.4) mas/yr, and a reddened M-dwarf SED. The paper concludes that YSES 2b is a background late-type M dwarf behind YSES 2, with the GRAVITY epochs providing the key parallax discriminant. No quantitative fit of the alternative Keplerian-orbit hypothesis is presented.

Significance. The conclusion, if robust, is scientifically valuable: it removes YSES 2b from the sample of directly imaged planets and reinforces the need for common-parallax tests rather than common-proper-motion tests in young associations. The paper’s strengths include the public reproducibility chain (`showyourwork`), the use of the open-source `backtracks` and `species` packages, and the comparison of the measured proper motion with Gaia field stars. However, the central claim rests on a parallax detection that is only ~1.4σ from zero and on a background fit with reduced χ²=3.02 that is not discussed; these issues need to be addressed before the conclusion can be considered established.

major comments (4)

[§4.1, Fig. 1] The text reports χ²ν=3.02 for the final eight-epoch background fit, but does not interpret this value. With five free parameters (two offsets, parallax, two proper motions) and 16 measured coordinates, χ²ν=3.02 indicates either underestimated uncertainties or model misspecification. Since the quoted parallax and proper-motion uncertainties are the basis for the background conclusion, the authors should examine the residuals, identify the largest outliers, and either adopt a more realistic error model or explicitly rescale the uncertainties. A direct statement of the impact of this on the derived parallax is essential.
[§1, §4.3] The introduction promises a comparison between Keplerian orbital motion and a background source, but no quantitative Keplerian fit is presented anywhere. Section 4.3 only contrasts the CPx and NCPx concepts in general terms. To claim that YSES 2b is not a bound companion, the authors need to fit (or refit) a Keplerian orbit to the same relative astrometry, or at least report the likelihood ratio/BIC between the two models. The earlier e>0.6 orbital interpretation from the literature is never quantitatively revisited.
[§4.2] The fitted parallax is 0.41^{+0.37}_{-0.28} mas, which is only about 1.4σ from zero. The abstract's statement that GRAVITY 'identified the sub-milliarcsecond parallactic motion' overstates the significance of this detection. The authors should compare the background fit with parallax forced to zero, show the resulting Δχ², and/or include an independent distance constraint. As written, the derived distance of 2.5 kpc and the consequent physical properties of the background object are not securely determined.
[§2.2, Table C.1] The four GRAVITY epochs come from only two calendar seasons (2022 March and 2023 May/June) and all use swap-binary phase referencing. A season-dependent zero-point in the swap calibration could produce a parallax-like signature in the relative astrometry. The paper itself notes systematics in the flux calibration of the swap-referenced epochs, but does not quantify astrometric stability. I ask for a null test (e.g., a known zero-parallax calibrator observed with the same swap scheme) or an explicit cross-check with the near-contemporaneous SPHERE epoch (2022-04-10 vs. 2022-03-20/21). Without this, the GRAVITY parallax is the least secure link in the chain.

minor comments (4)

[§2.2] The text says the source was observed 'five times' but Table C.1 and the following sentence refer to 'four GRAVITY epochs'. Please correct this inconsistency.
[§3.2 vs §4.2] The SED fit parameters differ between sections: §3.2 gives Teff=3110±100 K, logg=4.8±0.4, R=0.28±0.04 Rsun, Av=4.1±0.3; §4.2 says the best fit is Teff=3065 K, logg=4.4, R=0.5 Rsun, Av=2.7. Clarify which fit is the final one and whether these are different posterior summaries.
[§2.1] The phrase 'CRIRES (CRIRES; Kaeufl et al. 2004)' has a duplicated instrument name. The parentheses should contain only the reference.
[Fig. 2] The blue points representing the inferred background object are not labeled in the figure itself; please add labels and a description of the background contours to make the figure self-contained.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the background classification follows from an independent astrometric fit, not from an input equivalent to the conclusion.

full rationale

The paper's derivation chain is self-contained and not circular. The central claim that YSES 2b is a background M dwarf is inferred from a five-parameter background-helix model (position, proper motion, parallax) fit to eight epochs of relative astrometry from SPHERE and GRAVITY (Section 3.1, Table 1, Fig. 1). The fitted parallax of 0.41 mas and the proper motions are outputs of the fit, not inputs, and the host star's parallax of 9.15 mas (Section 4.3) provides an independent reference scale. The SED analysis (Section 3.2) adopts a normal prior on parallax from the astrometric posterior, but the spectral type (Teff ~ 3110 K) is constrained by the observed photometry/spectrum; the distance prior does not define the conclusion. No equation is defined in terms of the target conclusion, and no fitted parameter is relabeled as a prediction. Self-citations (Bohn et al. 2021 for earlier SPHERE epochs; Balmer et al. 2025 for the backtracks code; Nowak et al. 2020/2024 for exogravity and phase referencing; Stolker et al. 2020 for the species toolkit) are methodological or provide prior data; the load-bearing GRAVITY astrometry is new and calibrated using external stellar references (Tokovinin 2014; Makarov & Fabricius 2021; Gaia DR3). The reduced chi-square of 3.02 and the swap-binary phase-referencing systematics noted in Section 2.2 are genuine correctness/robustness concerns, but they are not circularity. The absence of a null test or cross-instrument check weakens the empirical case but does not make the derivation circular.

Assumptions & free parameters 9 free parameters · 4 assumptions · 0 invented entities

The central claim rests on five fitted astrometric parameters (position, parallax, proper motions) and four fitted SED parameters. These are all estimated from the data rather than predicted from first principles. The assumptions listed are standard astrometric and atmospheric modeling choices, none ad hoc to this paper.

free parameters (9)

RA offset of background source at reference epoch = not quoted in text; see Fig. B.1
Fitted to the relative astrometry; part of the background model.
Dec offset of background source at reference epoch = not quoted in text; see Fig. B.1
Fitted to the relative astrometry; part of the background model.
Background object parallax = 0.41 +0.37/-0.28 mas
Fitted to the astrometry; central to the NCPx classification. Weakly inconsistent with zero.
Background object proper motion in RA = -25.42 +0.25/-0.18 mas/yr
Fitted to the astrometry; shows the object has its own motion, not shared with YSES 2.
Background object proper motion in Dec = 4.40 +0.28/-0.30 mas/yr
Fitted to the astrometry; combined with pmRA gives the total proper motion.
SED effective temperature = 3110 +/- 100 K (also reported as 3065 K in Sect. 4.2)
Fitted to photometry and spectrum; used to classify the object as an M-dwarf. Inconsistent values across sections.
SED surface gravity = logg = 4.8 +/- 0.4 (also reported as 4.4 in Sect. 4.2)
Fitted to SED; supports late-type dwarf classification.
SED radius = 0.28 +/- 0.04 R_sun (also reported as 0.5 R_sun in Sect. 4.2)
Derived from SED fit and parallax prior; inconsistent values reported.
SED extinction A_V = 4.1 +/- 0.3 (also reported as 2.7 in Sect. 4.2)
Fitted to SED; the reddening supports a distant background star.

assumptions (4)

domain assumption The apparent motion of a background source is accurately described by a constant proper motion plus annual parallax (helical track).
Used by the backtracks model (Balmer et al. 2025) to interpret the relative astrometry; Sect. 3.1.
domain assumption Gaia DR3 astrometry and parallax for YSES 2 (parallax 9.15 mas) are correct.
The star's parallactic motion is the reference against which the background source's lack of parallax is measured; Sect. 4.3.
domain assumption The GRAVITY and SPHERE astrometric error bars are reliable estimators of uncertainty.
The fit quality and the significance of the parallax detection depend on these error bars; Sect. 2, Table 1.
domain assumption BT-Settl / BT-NextGen stellar model atmospheres are adequate to describe the SEDs of the target and reference stars.
Used in the SED fitting (Sect. 2.2, 3.2) to classify the object as an M-dwarf.

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Cite this review

Pith. "Pith review of YSES 2b is a background star: Differential astrometric M-dwarf measurements in time." pith.science (2026). https://pith.science/paper/YB2MSRTE

@misc{pith2026250909504,
  author       = {Pith},
  title        = {Pith review of: YSES 2b is a background star: Differential astrometric M-dwarf measurements in time},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/YB2MSRTE}},
  note         = {Machine review of arXiv:2509.09504}
}

read the original abstract

We wish to confirm the nature of YSES 2b, a purportedly faint companion of the young star YSES 2. We used on-sky observations from SPHERE and GRAVITY to measure the astrometric position of 2b with respect to the star YSES 2, and examined the competing hypotheses of (i) a bound substellar companion versus (ii) a distant unrelated background source with a non-zero proper motion. YSES 2b appears to be a late-type M-dwarf star over 2 kiloparsecs behind the star YSES 2. It has a transverse velocity of about 300 km/s and is located within one of the spiral arms of the Galaxy. The main discriminant was multiple epochs of GRAVITY astrometry that identified the sub-milliarcsecond parallactic motion of the star.

Figures

Figures reproduced from arXiv: 2509.09504 by the authors.

**Figure 2.** Comparison with the proper motions and parallaxes of all Gaia sources within 0.2 deg of YSES 2. The inferred parameters of the background star are indicated by the blue dots and lines. of stars based on a query of nearby Gaia sources. The parameters of the background object were sampled with the static nested sampling algorithm in the dynesty package (Speagle 2020), with 500 live points and an acceptance fraction … view at source ↗

**Figure 3.** Near-infrared SED of YSES 2b. The best-fit model spectrum is shown as black lines, and the grey lines are randomly drawn spectra from the posterior distribution. The residuals in the lower panel are normalised by the uncertainties of the data [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗

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Works this paper leans on

55 extracted references · 1 linked inside Pith

[1]

, " * write output.state after.block = add.period write newline

ENTRY address archiveprefix author booktitle chapter edition editor howpublished institution eprint journal key month note number organization pages publisher school series title type volume year label extra.label sort.label short.list INTEGERS output.state before.all mid.sentence after.sentence after.block FUNCTION init.state.consts #0 'before.all := #1 ...
[2]

write newline

" write newline "" before.all 'output.state := FUNCTION n.dashify 't := "" t empty not t #1 #1 substring "-" = t #1 #2 substring "--" = not "--" * t #2 global.max substring 't := t #1 #1 substring "-" = "-" * t #2 global.max substring 't := while if t #1 #1 substring * t #2 global.max substring 't := if while FUNCTION word.in bbl.in " " * FUNCTION format....
[3]

H., Alexander , D

Allard , F., Hauschildt , P. H., Alexander , D. R., Tamanai , A., & Schweitzer , A. 2001, , 556, 357

2001
[4]

2012, Philosophical Transactions of the Royal Society of London Series A, 370, 2765

Allard , F., Homeier , D., & Freytag , B. 2012, Philosophical Transactions of the Royal Society of London Series A, 370, 2765

2012
[5]

& Quanz , S

Amara , A. & Quanz , S. P. 2012, , 427, 948

2012
[6]

M., Sip o cz , B

Astropy Collaboration , Price-Whelan , A. M., Sip o cz , B. M., et al. 2018, , 156, 123

2018
[7]

P., Tollerud , E

Astropy Collaboration , Robitaille , T. P., Tollerud , E. J., et al. 2013, , 558, A33

2013
[8]

Bailer-Jones , C. A. L., Rybizki , J., Fouesneau , M., Demleitner , M., & Andrae , R. 2021, , 161, 147

2021

Show all 55 references

[9]

O., Otten , G

Balmer , W. O., Otten , G. P. P. L., & Stolker , T. 2025, backtracks: a python package to compare relative astrometry with background helical motion

2025
[10]

L., Vigan , A., Mouillet , D., et al

Beuzit , J. L., Vigan , A., Mouillet , D., et al. 2019, , 631, A155

2019
[11]

J., Ginski , C., Kenworthy , M

Bohn , A. J., Ginski , C., Kenworthy , M. A., et al. 2021, , 648, A73

2021
[12]

J., Kenworthy , M

Bohn , A. J., Kenworthy , M. A., Ginski , C., et al. 2020 a , , 492, 431

2020
[13]

J., Kenworthy , M

Bohn , A. J., Kenworthy , M. A., Ginski , C., et al. 2020 b , , 898, L16

2020
[14]

2014, , 564, A125

Buchner , J., Georgakakis , A., Nandra , K., et al. 2014, , 564, A125

2014
[15]

2000, , 542, 464

Chabrier , G., Baraffe , I., Allard , F., & Hauschildt , P. 2000, , 542, 464

2000
[16]

2025, , 696, A6

Denis , A., Vigan , A., Costes , J., et al. 2025, , 696, A6

2025
[17]

2008, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol

Dohlen , K., Langlois , M., Saisse , M., et al. 2008, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 7014, Ground-based and Airborne Instrumentation for Astronomy II, ed. I. S. McLean & M. M. Casali , 70143l

2008
[18]

& Hobson , M

Feroz , F. & Hobson , M. P. 2008, , 384, 449

2008
[19]

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

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

2013
[20]

Gaia Collaboration , Vallenari , A., Brown , A. G. A., et al. 2023, , 674, A1

2023
[21]

G., et al

Ginski , C., Benisty , M., van Holstein , R. G., et al. 2018, , 616, A79

2018
[22]

2017, , 602, A94

GRAVITY Collaboration , Abuter , R., Accardo , M., et al. 2017, , 602, A94

2017
[23]

2020, , 633, A110

Gravity Collaboration , Nowak , M., Lacour , S., et al. 2020, , 633, A110

2020
[24]

Y., van Holstein , R

Haffert , S. Y., van Holstein , R. G., Ginski , C., et al. 2020, , 640, L12

2020
[25]

Hoch , K. K. W., Rowland , M., Petrus , S., et al. 2025, , 643, 938

2025
[26]

Hunter , J. D. 2007, Computing in Science and Engineering, 9, 90

2007
[27]

2004, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol

Kaeufl , H.-U., Ballester , P., Biereichel , P., et al. 2004, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 5492, Ground-based Instrumentation for Astronomy, ed. A. F. M. Moorwood & M. Iye , 1218--1227

2004
[28]

2019, , 624, A99

Lacour , S., Dembet , R., Abuter , R., et al. 2019, , 624, A99

2019
[29]

2014, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol

Lapeyr\` e re , V., Kervella , P., Lacour , S., et al. 2014, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, Vol. 9146, Optical and Infrared Interferometry IV, ed. J. K. Rajagopal , M. J. Creech-Eakman , & F. Malbet , 91462D

2014
[30]

2021, arXiv e-prints, arXiv:2110.06271

Luger , R., Bedell , M., Foreman-Mackey , D., et al. 2021, arXiv e-prints, arXiv:2110.06271

2021 arXiv
[31]

2021, Journal of Astronomical Telescopes, Instruments, and Systems, 7, 035004

Maire , A.-L., Langlois , M., Delorme , P., et al. 2021, Journal of Astronomical Telescopes, Instruments, and Systems, 7, 035004

2021
[32]

Makarov , V. V. & Fabricius , C. 2021, , 162, 260

2021
[33]

2010, in SPIE Conference Series, Vol

Marois , C., Macintosh , B., & V \'e ran , J.-P. 2010, in SPIE Conference Series, Vol. 7736

2010
[34]

T., Costa , G., Girardi , L., et al

Nguyen , C. T., Costa , G., Girardi , L., et al. 2022, , 665, A126

2022
[35]

L., Rosa , R

Nielsen , E. L., Rosa , R. J. D., Rameau , J., et al. 2017, , 154, 218

2017
[36]

2024, , 687, A248

Nowak , M., Lacour , S., Abuter , R., et al. 2024, , 687, A248

2024
[37]

M., et al

Nowak , M., Lacour , S., Lagrange , A. M., et al. 2020, , 642, L2

2020
[38]

Oliphant, T. E. 2006, A guide to NumPy, Vol. 1 (Trelgol Publishing USA)

2006
[39]

F., Cutri , R

Skrutskie , M. F., Cutri , R. M., Stiening , R., et al. 2006, , 131, 1163

2006
[40]

2012, , 755, L28

Soummer , R., Pueyo , L., & Larkin , J. 2012, , 755, L28

2012
[41]

Speagle , J. S. 2020, , 493, 3132

2020
[42]

J., Quanz , S

Stolker , T., Bonse , M. J., Quanz , S. P., et al. 2019, , 621, A59

2019
[43]

P., Todorov , K

Stolker , T., Quanz , S. P., Todorov , K. O., et al. 2020, , 635, A182

2020
[44]

2014, , 147, 86

Tokovinin , A. 2014, , 147, 86

2014
[45]

2020, vlt-sphere: Automatic VLT/SPHERE data reduction and analysis , Astrophysics Source Code Library, record ascl:2009.002

Vigan , A. 2020, vlt-sphere: Automatic VLT/SPHERE data reduction and analysis , Astrophysics Source Code Library, record ascl:2009.002

2020
[46]

2024, , 682, A16

Vigan , A., El Morsy , M., Lopez , M., et al. 2024, , 682, A16

2024
[47]

2015, , 454, 129

Vigan , A., Gry , C., Salter , G., et al. 2015, , 454, 129

2015
[48]

2010, , 407, 71

Vigan , A., Moutou , C., Langlois , M., et al. 2010, , 407, 71

2010
[49]

2016, , 586, A144

Vigan , A., N'Diaye , M., Dohlen , K., et al. 2016, , 586, A144

2016
[50]

E., et al

Virtanen , P., Gommers , R., Oliphant , T. E., et al. 2020, Nature Methods, 17, 261

2020
[51]

2016, Science, 353, 673

Wagner , K., Apai , D., Kasper , M., et al. 2016, Science, 353, 673

2016
[52]

2000, , 143, 9

Wenger , M., Ochsenbein , F., Egret , D., et al. 2000, , 143, 9

2000
[53]

L., Eisenhardt , P

Wright , E. L., Eisenhardt , P. R. M., Mainzer , A. K., et al. 2010, , 140, 1868

2010
[54]

2016, , 587, A57

Zurlo , A., Vigan , A., Galicher , R., et al. 2016, , 587, A57

2016
[55]

2014, , 572, A85

Zurlo , A., Vigan , A., Mesa , D., et al. 2014, , 572, A85

2014

Pith tools

Reviewed August 4, 2026 · model on record in the stance chip above.

[1] [1]

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[2] [2]

write newline

" write newline "" before.all 'output.state := FUNCTION n.dashify 't := "" t empty not t #1 #1 substring "-" = t #1 #2 substring "--" = not "--" * t #2 global.max substring 't := t #1 #1 substring "-" = "-" * t #2 global.max substring 't := while if t #1 #1 substring * t #2 global.max substring 't := if while FUNCTION word.in bbl.in " " * FUNCTION format....

[3] [3]

H., Alexander , D

Allard , F., Hauschildt , P. H., Alexander , D. R., Tamanai , A., & Schweitzer , A. 2001, , 556, 357

2001

[4] [4]

2012, Philosophical Transactions of the Royal Society of London Series A, 370, 2765

Allard , F., Homeier , D., & Freytag , B. 2012, Philosophical Transactions of the Royal Society of London Series A, 370, 2765

2012

[5] [5]

& Quanz , S

Amara , A. & Quanz , S. P. 2012, , 427, 948

2012

[6] [6]

M., Sip o cz , B

Astropy Collaboration , Price-Whelan , A. M., Sip o cz , B. M., et al. 2018, , 156, 123

2018

[7] [7]

P., Tollerud , E

Astropy Collaboration , Robitaille , T. P., Tollerud , E. J., et al. 2013, , 558, A33

2013

[8] [8]

Bailer-Jones , C. A. L., Rybizki , J., Fouesneau , M., Demleitner , M., & Andrae , R. 2021, , 161, 147

2021