Pith. sign in

REVIEW 4 major objections 5 minor 1 cited by

S and VV Corona Australis: Spectroscopic Variability in Two Young Binary Star Systems

T0 review · 4 major / 5 minor · reviewed 2026-08-14 · deepseek-v4-flash

Pith's one-line read All four stars in the S CrA and VV CrA binaries are actively accreting and bridge the Class I–Class II evolutionary stages

desk verdict First spectral types and multi-epoch veiling for S/VV CrA are genuinely useful, but the SED classification is too shaky to support the 'Class I/II bridging' claim without revisions. read the letter →

arxiv 1908.06135 v1 pith:KO666RJD submitted 2019-08-16 astro-ph.SR

classification astro-ph.SR
keywords TTauristarsyoungbinarynear-infraredspectroscopyveilingaccretionluminosityspectralenergydistributionsCoronaAustralisClassI/ClassIItransition
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 uses five years of high-resolution near-infrared spectra to characterize all four stars in the young binary systems S CrA and VV CrA in the Corona Australis star-forming region. It establishes the first spectral types for the components (K7 for S CrA A, M1 for S CrA B and VV CrA A, M0 for VV CrA B) and shows that their near-infrared veiling and hydrogen emission lines vary strongly from epoch to epoch. Combining these spectra with archival photometry, the authors place the four stars at roughly the same young evolutionary stage, with accretion luminosities higher than those typical of classical T Tauri stars, and conclude that the systems are bridging the Class I and Class II phases. If correct, these closely matched stars offer a controlled comparison for how individual stellar properties and shared environments shape disk accretion and veiling.

What carries the argument

The argument rests on simultaneous spectral typing and veiling measurement using the depth ratio of two Fe I lines at $1.562$ and $1.563\,\mu$m flanking an unresolved OH doublet near $1.5625\,\mu$m in the observed H-band order. Because the OH/Fe ratio is temperature-sensitive in low-mass stars, matching a veiled template to the observed line ratios yields both the spectral type and the H-band veiling at each epoch. Around this core sit the SED spectral index $\alpha = d\log(\lambda F_\lambda)/d\log \lambda$, measured between 2.3 and 10.5 $\mu$m, which assigns each component to Classes I, flat-spectrum, or II, and the $\mathrm{Pa}\beta$ and $\mathrm{Br}\gamma$ line-luminosity relations that convert measured equivalent widths into accretion luminosities and mass accretion rates. The same H-band order also contains the $\mathrm{Br}_{16}$ emission line, whose veiling-corrected equivalent widths are compared with the measured veiling across epochs.

What would settle it

Take new adaptive-optics JHK and mid-infrared imaging of both systems in a single epoch, measure the component flux ratios and fluxes simultaneously, and recompute the SED spectral indices; if all four $\alpha$ values fall below $-0.3$, the flat-spectrum and Class I classifications, and with them the bridging-stage conclusion, would be overturned.

Watch

Extended reading notes

Core claim

The central discovery is that this paper establishes the first spectral types for all four components of S CrA and VV CrA and finds that the systems are not classical Class II T Tauri stars but objects in transition between the Class I and Class II embedded stages. All four components are actively accreting from optically thick circumstellar disks, with high, time-variable near-infrared veiling and hydrogen emission lines. The SED spectral indices place S CrA A, S CrA B, and VV CrA A in the flat-spectrum category ($\alpha \approx -0.17$, $-0.17$, and $0.13$) and VV CrA B in Class I ($\alpha = 0.37$), with silicate absorption in VV CrA consistent with an earlier embedded stage. The paper also finds that the infrared companion VV CrA B has an earlier spectral type (M0) than VV CrA A (M1), making it the more massive component despite being fainter at shorter wavelengths because of its high extinction.

Load-bearing premise

The load-bearing premise is that the 2015 secondary-to-primary flux ratios, which the paper itself shows changed dramatically over earlier epochs, are representative of the epochs when the older JHK and mid-infrared photometry used to build the SEDs was taken; if not, the derived spectral indices could cross the class boundaries.

Editorial extensions

If this is right

  • If the classification is right, S CrA A, S CrA B, and VV CrA A are flat-spectrum sources rather than Class II, and VV CrA B is Class I, so the two binaries occupy the evolutionary window in which infalling envelopes are giving way to circumstellar disks.
  • The four components share similar masses, ages, and temperatures, so differences in veiling, accretion, and emission-line strength between them point to systemic or environmental factors rather than gross stellar parameters.
  • Because VV CrA B is M0 and hence more massive than its M1 primary, the nominal 'secondary' in this infrared companion system is actually the more massive star, hidden by extinction.
  • The mass accretion rates derived here, roughly $10^{-8}\,M_\odot\,\mathrm{yr}^{-1}$ and exceeding typical T Tauri values, imply these are relatively young, vigorously accreting systems.
  • The epoch-to-epoch changes in veiling and $\mathrm{Br}_{16}$ emission mean that single-epoch snapshots misrepresent the accretion state, so multi-epoch monitoring is required to characterize such systems.

Reading between the lines

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

  • If the slope of the veiling versus $\mathrm{Br}_{16}$ equivalent-width relation traces the inner dust truncation radius relative to the corotation radius, then the systematic difference between S CrA and VV CrA could be tested directly by measuring inner-disk radii with infrared or submillimeter interferometry in both systems.
  • Because component flux ratios varied by factors of several to ten between 1996 and 2015, SED-based evolutionary classifications of close young binaries are only as reliable as the epoch matching between the resolved flux ratios and the broadband photometry; future surveys should prioritize contemporaneous measurements.
  • The Fe I/OH line-ratio method demonstrated here could be applied to other embedded young binaries to map the Class I–Class II transition across a larger population, provided similar high-resolution H-band spectra are available.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

4 major / 5 minor

Summary. The paper presents multi-epoch Keck/NIRSPEC H-band spectroscopy of all four components of the young binary systems S CrA and VV CrA, supplemented by archival J- and K-band spectra and 2015 NIRC2 adaptive-optics photometry. The authors determine spectral types for the four stars, measure H-band veiling at multiple epochs, measure Br16 equivalent widths and correct them for veiling, derive Paβ and Brγ accretion luminosities and mass accretion rates, and construct component-resolved SEDs from new and archival photometry. The central conclusion is that S CrA and VV CrA are young binary systems bridging the Class I and Class II evolutionary stages, with high accretion luminosities and variable emission lines.

Significance. If the results hold, the paper supplies the first secure spectral classification of all four components, a valuable multi-epoch veiling record, and one of the few component-resolved SEDs for such close binaries. The careful template-based spectral typing, the explicit treatment of the J- and K-band equivalent widths as lower limits, and the use of archival plus new data are strengths. However, the evolutionary-stage claim rests on epoch-mixed SED construction, and the veiling-versus-equivalent-width correlation is partly algebraic, so the central conclusions are not yet established at the level of rigor claimed in the abstract.

major comments (4)
  1. [Section 3.7, Tables 4 and 8] The four spectral indices that drive the "bridging Class I/II" conclusion are computed by combining 2015 AO flux ratios (Table 3) with 2MASS/WISE, Prato et al. (2003), McCabe et al. (2006), and Scicluna et al. (2016) photometry from different epochs, and no uncertainty is quoted for any α. The paper itself shows that secondary-to-primary flux ratios change by large factors (VV CrA J ratio: 0.25 in 1996 vs 0.015 in 2015, Section 2.2), so the assumption that the 2015 ratios describe the earlier photometric epochs is not justified. Because VV CrA B's α = 0.37 sits only 0.07 above the Class I/flat-spectrum boundary, a plausible epoch-related shift could move it into the flat-spectrum or Class II category and remove the only Class I object. Please recompute α from single-epoch ratios or quantify how α varies when the ratios are allowed to vary across their observed range.
  2. [Section 3.7, Table 4] The text states that silicate emission in S CrA A "agrees with its spectral index to verify its classification as a Class II source," but α = -0.17 lies in the flat-spectrum range (0.3 to -0.3) by the paper's own definition. This is an internal inconsistency in the classification scheme. Please either classify S CrA A as flat-spectrum and discuss the consequence for the evolutionary-stage claim, or provide a definition that makes α = -0.17 consistent with Class II.
  3. [Section 3.6, Table 7, Figure 4] The plotted "veiling-corrected" Br16 equivalent width is computed as EW_obs × (1 + rH), and the observed Br16 EWs in Table 5 are nearly constant for each star. The plotted quantity is therefore essentially a linear function of rH by construction, so the reported small p-values for VV CrA A and B do not by themselves demonstrate a physical correlation between accretion emission and NIR veiling. Please add a regression of the observed (uncorrected) EW against rH, or a permutation test that randomizes the observed EWs, to show that the correlation is not introduced by the correction factor.
  4. [Section 3.5, Table 6] The accretion luminosities and mass accretion rates are labeled lower limits because the Paβ and Brγ EWs are not veiling-corrected and because the line EWs, photometry, and flux ratios come from epochs separated by as much as ~13 years, yet Section 5 states the "high accretion luminosity" result as a firm conclusion. The text acknowledges a possible ~1 mag uncertainty from the epoch mismatch (citing Gahm et al. 2008); please propagate this into Lacc and Ṁ and state explicitly whether the "high accretion" conclusion survives when the input fluxes are varied by that amount.
minor comments (5)
  1. [Section 3.4 and Table 2] The text refers to a "single epoch (2003/05/23 UT)" for the Paβ and Brγ measurements, but Table 2 lists no observation on that date; the closest entries are 2003/05/14 and 2003/09/07. Please correct the date or the table.
  2. [Table 6] The row label "VV CrA" should read "VV CrA A" for consistency with the other rows.
  3. [Section 3.7] The spectral-index equation is written as α = d log(λFλ)/d log(λ) = αλ2 − αλ1; the second equality omits the denominator and should be written as (log(λ2F2) − log(λ1F1))/(log λ2 − log λ1), with the flux convention specified explicitly.
  4. [Table 4 note] The note says α is measured "between 10.5 and 2.3 μm," which reverses the order of the wavelengths given in the text (λ1 ≈ 10.5 μm, λ2 ≈ 2.3 μm); please make the convention consistent.
  5. [Facility line] The facility is listed as "Keck:II (ESI)" in the acknowledgments, but the observations were made with NIRSPEC; please correct this.

Circularity Check

1 steps flagged · score 4.0 of 10

The central Class I/II classification is not circular, but the Section 3.6 veiling–Br16 EW correlation is partly constructed from the veiling-correction definition.

  1. self definitional [Section 3.4 (Equation for EW correction) and Section 3.6 (Veiling/Equivalent Width correlation, Table 7)]
    "Because this line is adjacent to the spectral features used to determine veiling, we were able to correct the measured equivalent widths for the veiling at each epoch, such that EWcorrected = EWobserved ∗ (1 +r1.55). ... We plotted the veiling-corrected Br16 equivalent widths against the H band continuum veiling for each star at each epoch (Figure 4). We performed a linear regression fit to the data; a P-value of less than 0.05 indicates a statistically significant correlation (Table 7)."

    The ordinate in Figure 4, EW_corrected, is defined as EW_observed × (1 + r_H). Thus any regression of EW_corrected against r_H contains an automatic linear term r_H. Table 5 shows the observed EWs are nearly constant within each star (e.g., VV CrA A observed EWs range only 1.3–2.1 Å while r_H ranges 1.3–3.0), so the plotted relation is essentially a scaled and shifted copy of (1 + r_H). The small p-values in Table 7 therefore follow algebraically from the correction formula and do not independently establish a physical correlation between Br16 strength and veiling. The paper presents this as evidence that veiling traces accretion, but that inference is partly an artifact of how the corrected EW was defined.

full rationale

The paper's headline claim—that S CrA and VV CrA bridge the Class I and Class II stages—rests on SED spectral indices computed from resolved photometry and standard Lada/Greene thresholds; that derivation is not circular, though it is subject to a correctness risk from mixing 2015 flux ratios with older 2MASS/WISE, McCabe et al., and Scicluna et al. photometry. The spectral types, veiling measurements, and accretion-luminosity estimates are likewise independent empirical measurements using external templates and calibrations; the several self-citations (Prato et al. 2003, McCabe et al. 2006, Schaefer et al. 2014/2018) are data sources, not load-bearing uniqueness claims. The one genuine circular step is the Section 3.6 veiling–Br16 EW correlation, where the y-variable is defined from the x-variable via EW_corrected = EW_observed(1 + r_H), making the reported strong correlation and p-values largely mathematical. This is a secondary result, not the central classification claim, so it does not by itself force the paper's main conclusion; however, the paper's discussion uses this correlation to argue that NIR veiling traces accretion, and that specific inference is weakened by the construction. The internal inconsistency of labeling S CrA A (alpha = -0.17) as Class II and VV CrA A (alpha = 0.13) as 'Class I or slightly later' is noted, but it is an interpretive inconsistency rather than circularity.

Assumptions & free parameters 3 free parameters · 7 assumptions · 0 invented entities

The central characterization rests on external template libraries, isochrones, empirical accretion-luminosity calibrations, and adopted extinctions; the paper contributes the measurements themselves. Two internal choices are load-bearing: treating the 2015 flux ratios as representative for mixed-epoch SEDs, and defining the EW-veiling correlation with a correction that already contains the veiling. No new physical entities are introduced.

free parameters (3)
  • H-band veiling rH = 0.5 to 8.6 per star and epoch (Table 5)
    Determined by scaling template spectra to match observed line depths; used to correct Br16 equivalent widths and is the subject of the EW-veiling correlation in Section 3.6.
  • Assumed distance to S CrA = 150 pc
    Adopted from VV CrA's Gaia parallax because S CrA's own parallax is unreliable (Section 3.2); affects all luminosity, age, and mass estimates.
  • Per-star extinction A_V = 2.0, 2.0, 1.7, 10.2 mag
    Adopted from Varga et al. (2018) and used to deredden fluxes for SEDs and accretion luminosities; the paper does not independently verify these values.
assumptions (7)
  • domain assumption Baraffe et al. (2015) isochrones provide valid masses, radii, and luminosities for these pre-main-sequence stars.
    Used in Sections 3.2 and 3.5 to convert spectral types and magnitudes into ages, masses, radii, and stellar luminosities.
  • domain assumption Alcala et al. (2017) empirical relations between hydrogen line luminosity and accretion luminosity apply to these systems.
    The Br-gamma and Pa-beta accretion luminosities in Table 6 are computed from these relations (Section 3.5).
  • domain assumption The extinction law A_lambda = A_V [0.55/lambda]^1.6 and the A_V values from Varga et al. (2018) are correct for all four stars.
    Used to deredden fluxes before computing line luminosities, accretion rates, and SED spectral indices (Sections 3.5 and 3.7).
  • ad hoc to paper The 2015 AO flux ratios are representative of the epochs of the older photometry used in the SEDs.
    Component-resolved SEDs in Figure 5 and Table 8 combine 2015 NIRC2 flux ratios with 2006 and 2016 photometry; the paper shows flux ratios vary substantially over time.
  • domain assumption The main-sequence template stars GJ 281, GJ 763, and GJ 752a are adequate spectral standards for these pre-main-sequence stars.
    Spectral typing relies on these templates; the authors note surface gravity effects are small below 4000 K (Section 3.3).
  • domain assumption J-band veiling is negligible when deriving absolute magnitudes and ages.
    Section 3.2 states excess emission is typically least significant in J, but no J-band veiling is measured.
  • domain assumption The inner disk radius is 5 stellar radii (Gullbring et al. 1998), used in the mass accretion rate conversion.
    Section 3.5 assumes R_in = 5 R_star to convert accretion luminosity into mass accretion rate.

how reviews work

0 comments
Cite this review

Pith. "Pith review of S and VV Corona Australis: Spectroscopic Variability in Two Young Binary Star Systems." pith.science (2026). https://pith.science/paper/KO666RJD

@misc{pith2026190806135,
  author       = {Pith},
  title        = {Pith review of: S and VV Corona Australis: Spectroscopic Variability in Two Young Binary Star Systems},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/KO666RJD}},
  note         = {Machine review of arXiv:1908.06135}
}
read the original abstract

We used high-resolution near-infrared spectroscopy from the NIRSPEC instrument on the Keck II telescope, taken over multiple epochs spanning five years, to examine two young binary T Tauri star systems, S Corona Australis and VV Corona Australis. The stars in these 1-2" separation systems have optically thick circumstellar disks and high extinctions at optical and near-infrared wavelengths. Using a combination of new and archival data, we have determined the spectral types of all the stars in these two systems for the first time, examined the variable NIR veiling, measured the emission line equivalent widths, and created spectral energy distributions. They have similar spectral types (K7-M1) and are at approximately the same evolutionary stage, allowing comparison of the four stars in the two systems. We conclude that S CrA and VV CrA are young binary systems of stars bridging the Class I and Class II evolutionary stages, characterized by high accretion luminosities and variable emission lines.

Figures

Figures reproduced from arXiv: 1908.06135 by the authors.

Figure 1
Figure 1. NIRSPEC order 49 H-band spectra of target binaries. Both Brackett 16 emission and numerous atomic and molecular absorption features are present in this order; particularly useful are the two FeI lines flanking an unresolved OH doublet at ∼1.563 µm. The variations in absorption line depths are caused by variable veiling. The UT dates of observation and veiling values are indicated on the left and right side of the fi… view at source ↗
Figure 2
Figure 2. J- (order 59, left column) and K-band (order 35, right column) spectra for S CrA and VV CrA showing the Paschen β and Brackett γ emission lines, respectively. Only the primary component of VV CrA was detectable in the J band at the time of observation. The data were all taken on UT 2008 May 23. These spectra have not been divided by a telluric standard star as they were only used for measuring emission line strength… view at source ↗
Figure 3
Figure 3. S CrA A (solid black) from 2004/07/22 UT, with the best fit template star, a K7 spectral type (dotted blue) scaled to the veiling value for that date (2.9) and overplotted, along with the residual spectrum from subtracting the data from the template (green). The Fe and OH lines used for spectral type determination are marked with vertical fuchsia lines. The K7 spectral template is GJ 281, which has a spectral type o… view at source ↗
Figures from the paper (2 more)
Figure 4
Figure 4. Figure 4: Veiling-corrected Br16 equivalent width versus continuum veiling. Uncertainties are on the order of or smaller than the plotted points [PITH_FULL_IMAGE:figures/full_fig_p010_4.png]
Figure 5
Figure 5. Figure 5: Spectral energy distributions for S CrA and VV CrA. Median SEDs of young stars of the same spectral type as S CrA and VV CrA are plotted as the turquoise line (Fang et al. 2013). The MIR data are from McCabe et al. (2006) and Scicluna et al. (2016) for S CrA and VV CrA…

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Circumstellar and circumbinary discs in multiple stellar systems

    astro-ph.EP 2025-01 conditional novelty 1.0 of 10

    This review consolidates current knowledge on how stellar multiplicity shapes protoplanetary disc structure, dust evolution, and planet formation outcomes.

Reference graph

Works this paper leans on

79 extracted references · 25 canonical work pages · cited by 1 Pith paper

  1. [1]

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

    ENTRY address archivePrefix author booktitle chapter doi edition editor eprint howpublished institution journal key month number organization pages publisher school series title misctitle type volume year version url label extra.label sort.label short.list INTEGERS output.state before.all mid.sentence after.sentence after.block FUNCTION init.state.consts ...

  2. [2]

    write newline

    " write newline "" before.all 'output.state := FUNCTION format.url url empty "" new.block "" url * "" * if FUNCTION format.eprint eprint empty "" archivePrefix empty "" archivePrefix "arXiv" = new.block " " eprint * " " * new.block " " eprint * " " * if if if FUNCTION format.doi doi empty "" " " doi * " " * if FUNCTION format.pid doi empty eprint empty ""...

  3. [3]

    op 0> l !н-YvN 4T 2m w <gv ̅| YP8ӀqJnL;9|m . i \ ִ

    thebibliography [1] 20pt to REFERENCES 6pt =0pt 10pt plus 3pt =0pt =0pt =1pt plus 1pt =0pt =0pt -12pt =13pt plus 1pt =20pt =13pt plus 1pt \@M =10000 =-1.0em =0pt =0pt 0pt =0pt =1.0em @enumiv\@empty 10000 10000 `\.\@m \@noitemerr \@latex@warning Empty `thebibliography' environment \@ifnextchar \@reference \@latexerr Missing key on reference command Each re...

  4. [4]

    C., Lada , C

    Adams , F. C., Lada , C. J., & Shu , F. H. 1987, APJ, 312, 788, 10.1086/164924

  5. [5]

    L., Jensen , E

    Akeson , R. L., Jensen , E. L. N., Carpenter , J., et al. 2019, APJ, 872, 158, 10.3847/1538-4357/aaff6a

  6. [6]

    M., Manara , C

    Alcal \'a , J. M., Manara , C. F., Natta , A., et al. 2017, AAP, 600, A20, 10.1051/0004-6361/201629929

  7. [7]

    S., Gutermuth , R

    Allen , T. S., Gutermuth , R. A., Kryukova , E., et al. 2012, APJ, 750, 125, 10.1088/0004-637X/750/2/125

  8. [8]

    M., & Williams , J

    Andrews , S. M., & Williams , J. P. 2005, APJ, 619, L175, 10.1086/427325

Show all 79 references
  1. [9]

    Bailer-Jones , C. A. L., Rybizki , J., Fouesneau , M., Mantelet , G., & Andrae , R. 2018, AJ, 156, 58, 10.3847/1538-3881/aacb21

  2. [10]

    Baraffe , I., Chabrier , G., Allard , F., & Hauschildt , P. H. 1998, , 337, 403. astro-ph/9805009

  3. [11]

    2015, AAP, 577, A42, 10.1051/0004-6361/201425481

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

  4. [12]

    Bate , M. R. 2018, MNRAS, 475, 5618, 10.1093/mnras/sty169

  5. [13]

    G., & Rossano , G

    Bellingham , J. G., & Rossano , G. S. 1980, AJ, 85, 555, 10.1086/112711

  6. [14]

    2005, AJ, 129, 402, 10.1086/426331

    Bender , C., Simon , M., Prato , L., Mazeh , T., & Zucker , S. 2005, AJ, 129, 402, 10.1086/426331

  7. [15]

    1998, APJ, 509, 802, 10.1086/306527

    Calvet , N., & Gullbring , E. 1998, APJ, 509, 802, 10.1086/306527

  8. [16]

    E., & Henning , T

    Carmona , A., van den Ancker , M. E., & Henning , T. 2007, AAP, 464, 687, 10.1051/0004-6361:20065509

  9. [17]

    W., Mathieu , R

    Casey , B. W., Mathieu , R. D., Vaz , L. P. R., Andersen , J., & Suntzeff , N. B. 1998, AJ, 115, 1617, 10.1086/300270

  10. [18]

    F., Liu , H

    Cazzoletti , P., Manara , C. F., Liu , H. B., et al. 2019, arXiv e-prints, arXiv:1904.02409. 1904.02409

  11. [19]

    G., Myers , P

    Chen , H., Grenfell , T. G., Myers , P. C. , & Hughes , J. D. 1997, APJ, 478, 295, 10.1086/303769

  12. [20]

    A., Padgett , D

    Cieza , L. A., Padgett , D. L., Allen , L. E., et al. 2009, APJL, 696, L84, 10.1088/0004-637X/696/1/L84

  13. [21]

    2006, APJ, 638, 314, 10.1086/498861

    D'Alessio , P., Calvet , N., Hartmann , L., Franco-Hern \'a ndez , R., & Serv \' n , H. 2006, APJ, 638, 314, 10.1086/498861

  14. [22]

    V., & Lamzin , S

    Dodin , A. V., & Lamzin , S. A. 2012, Astronomy Letters, 38, 649, 10.1134/S1063773712100027

  15. [23]

    1991, AAP, 248, 485

    Duquennoy , A., & Mayor , M. 1991, AAP, 248, 485

  16. [24]

    D., Davies , J

    Eiroa , C., Oudmaijer , R. D., Davies , J. K., et al. 2002, AAP, 384, 1038, 10.1051/0004-6361:20020096

  17. [25]

    M., Covey , K

    Faesi , C. M., Covey , K. R., Gutermuth , R., et al. 2012, Publications of the Astronomical Society of the Pacific, 124, 1137, 10.1086/668548

  18. [26]

    S., van Boekel, R., et al

    Fang, M., Kim, J. S., van Boekel, R., et al. 2013, The Astrophysical Journal Supplement Series, 207, 5

  19. [27]

    F., et al

    Fedele , D., Bruderer , S., van Dishoeck , E. F., et al. 2013, AAP, 559, A77, 10.1051/0004-6361/201321118

  20. [28]

    2011, APJ, 730, 73, 10.1088/0004-637X/730/2/73

    Fischer , W., Edwards , S., Hillenbrand , L., & Kwan , J. 2011, APJ, 730, 73, 10.1088/0004-637X/730/2/73

  21. [29]

    Folha , D. F. M., & Emerson , J. P. 1999, AAP, 352, 517

  22. [30]

    F., Petrov , P

    Gahm , G. F., Petrov , P. P., Tambovsteva , L. V., et al. 2018, AAP, 614, A117, 10.1051/0004-6361/201832891

  23. [31]

    F., Walter , F

    Gahm , G. F., Walter , F. M., Stempels , H. C., Petrov , P. P., & Herczeg , G. J. 2008, AAP, 482, L35, 10.1051/0004-6361:200809488

  24. [32]

    Gaia Collaboration , Prusti , T., de Bruijne , J. H. J., et al. 2016, , 595, A1, 10.1051/0004-6361/201629272

  25. [33]

    Gaia Collaboration , Brown , A. G. A., Vallenari , A., et al. 2018, , 616, A1, 10.1051/0004-6361/201833051

  26. [34]

    Graham , J. A. 1992, PASP, 104, 479, 10.1086/133021

  27. [35]

    2017, , 608, A78, 10.1051/0004-6361/201731058

    Gravity Collaboration , Garcia Lopez , R., Perraut , K., et al. 2017, , 608, A78, 10.1051/0004-6361/201731058

  28. [36]

    P., Wilking , B

    Greene , T. P., Wilking , B. A., Andre , P., Young , E. T., & Lada , C. J. 1994, APJ, 434, 614, 10.1086/174763

  29. [37]

    1998, APJ, 492, 323, 10.1086/305032

    Gullbring , E., Hartmann , L., Brice \ n o , C., & Calvet , N. 1998, APJ, 492, 323, 10.1086/305032

  30. [38]

    J., & Hillenbrand , L

    Herczeg , G. J., & Hillenbrand , L. A. 2008, APJ, 681, 594, 10.1086/586728

  31. [39]

    2008, APJ, 686, 1195, 10.1086/591224

    Hern \'a ndez , J., Hartmann , L., Calvet , N., et al. 2008, APJ, 686, 1195, 10.1086/591224

  32. [40]

    A., Strom , S

    Hillenbrand , L. A., Strom , S. E., Calvet , N., et al. 1998, AJ, 116, 1816, 10.1086/300536

  33. [41]

    Jensen , E. L. N., Mathieu , R. D., & Fuller , G. A. 1996, APJ, 458, 312, 10.1086/176814

  34. [42]

    Joy , A. H. 1945, APJ, 102, 168, 10.1086/144749

  35. [43]

    2017, APJ, 844, 168, 10.3847/1538-4357/aa7c60

    Kellogg , K., Prato , L., Torres , G., et al. 2017, APJ, 844, 168, 10.3847/1538-4357/aa7c60

  36. [44]

    2015, REDSPEC: NIRSPEC data reduction , Astrophysics Source Code Library

    Kim , S., Prato , L., & McLean , I. 2015, REDSPEC: NIRSPEC data reduction , Astrophysics Source Code Library. 1507.017

  37. [45]

    o hler , R., Neuh \

    K \"o hler , R., Neuh \"a user , R., Kr \"a mer , S., et al. 2008, AAP, 488, 997, 10.1051/0004-6361:200809897

  38. [46]

    D., Herbst , T

    Koresko , C. D., Herbst , T. M., & Leinert , C. 1997, APJ, 480, 741, 10.1086/303993

  39. [47]

    A., et al

    K \'o sp \'a l , \'A ., \'A brah \'a m , P., Acosta-Pulido , J. A., et al. 2012, APJS, 201, 11, 10.1088/0067-0049/201/2/11

  40. [48]

    L., Ireland , M

    Kraus , A. L., Ireland , M. J., Hillenbrand , L. A., & Martinache , F. 2012, APJ, 745, 19, 10.1088/0004-637X/745/1/19

  41. [49]

    L., Ireland , M

    Kraus , A. L., Ireland , M. J., Huber , D., Mann , A. W., & Dupuy , T. J. 2016, AJ, 152, 8, 10.3847/0004-6256/152/1/8

  42. [50]

    J., Richter , M

    Kruger , A. J., Richter , M. J., Carr , J. S., et al. 2011, APJ, 729, 145, 10.1088/0004-637X/729/2/145

  43. [51]

    Lada , C. J. 1987, in IAU Symposium, Vol. 115, Star Forming Regions, ed. M. Peimbert & J. Jugaku , 1--17

  44. [52]

    E., J rgensen , J

    Lindberg , J. E., J rgensen , J. K., Watanabe , Y., et al. 2015, AAP, 584, A28, 10.1051/0004-6361/201526222

  45. [53]

    L., Brice \ n o , C., Stauffer , J

    Luhman , K. L., Brice \ n o , C., Stauffer , J. R., et al. 2003, APJ, 590, 348, 10.1086/374983

  46. [54]

    Luri , X., Brown , A. G. A., Sarro , L. M., et al. 2018, AAP, 616, A9, 10.1051/0004-6361/201832964

  47. [55]

    F., Testi , L., Herczeg , G

    Manara , C. F., Testi , L., Herczeg , G. J., et al. 2017, AAP, 604, A127, 10.1051/0004-6361/201630147

  48. [56]

    2010, AAP, 520, A79, 10.1051/0004-6361/200913725

    Mart \' nez-Arn \'a iz , R., Maldonado , J., Montes , D., Eiroa , C., & Montesinos , B. 2010, AAP, 520, A79, 10.1051/0004-6361/200913725

  49. [57]

    M., Prato , L., et al

    McCabe , C., Ghez , A. M., Prato , L., et al. 2006, APJ, 636, 932, 10.1086/498207

  50. [58]

    2003, APJL, 597, L149, 10.1086/379921

    Muzerolle , J., Calvet , N., Hartmann , L., & D'Alessio , P. 2003, APJL, 597, L149, 10.1086/379921

  51. [59]

    2001, AAP, 371, 186, 10.1051/0004-6361:20010334

    Natta , A., Prusti , T., Neri , R., et al. 2001, AAP, 371, 186, 10.1051/0004-6361:20010334

  52. [60]

    2006, AAP, 452, 245, 10.1051/0004-6361:20054706

    Natta , A., Testi , L., & Randich , S. 2006, AAP, 452, 245, 10.1051/0004-6361:20054706

  53. [61]

    P., Gahm , G

    Petrov , P. P., Gahm , G. F., Herczeg , G. J., Stempels , H. C., & Walter , F. M. 2014, AAP, 568, L10, 10.1051/0004-6361/201424374

  54. [62]

    2007, APJ, 657, 338, 10.1086/510882

    Prato , L. 2007, APJ, 657, 338, 10.1086/510882

  55. [63]

    P., & Simon , M

    Prato , L., Greene , T. P., & Simon , M. 2003, APJ, 584, 853, 10.1086/345828

  56. [64]

    2002, APJ, 569, 863, 10.1086/339397

    Prato , L., Simon , M., Mazeh , T., et al. 2002, APJ, 569, 863, 10.1086/339397

  57. [65]

    A., Henry , T

    Raghavan , D., McAlister , H. A., Henry , T. J., et al. 2010, The Astrophysical Journal Supplement Series, 190, 1, 10.1088/0067-0049/190/1/1

  58. [66]

    P., Clarke , C

    Rosotti , G. P., Clarke , C. J., Manara , C. F., & Facchini , S. 2017, MNRAS, 468, 1631, 10.1093/mnras/stx595

  59. [67]

    H., Prato , L., & Simon , M

    Schaefer , G. H., Prato , L., & Simon , M. 2018, AJ, 155, 109, 10.3847/1538-3881/aaa59a

  60. [68]

    H., Prato , L., Simon , M., & Patience , J

    Schaefer , G. H., Prato , L., Simon , M., & Patience , J. 2014, AJ, 147, 157, 10.1088/0004-6256/147/6/157

  61. [69]

    A., Wolf , S., Hummel , C

    Schegerer , A. A., Wolf , S., Hummel , C. A., Quanz , S. P., & Richichi , A. 2009, AAP, 502, 367, 10.1051/0004-6361/200810782

  62. [70]

    2016, MNRAS, 458, 2476, 10.1093/mnras/stw460

    Scicluna , P., Wolf , S., Ratzka , T., et al. 2016, MNRAS, 458, 2476, 10.1093/mnras/stw460

  63. [71]

    R., Campbell , R., et al

    Service , M., Lu , J. R., Campbell , R., et al. 2016, PASP, 128, 095004, 10.1088/1538-3873/128/967/095004

  64. [72]

    2013, AAP, 551, A34, 10.1051/0004-6361/201220170

    Sicilia-Aguilar , A., Henning , T., Linz , H., et al. 2013, AAP, 551, A34, 10.1051/0004-6361/201220170

  65. [73]

    R., Hillenbrand , L

    Soderblom , D. R., Hillenbrand , L. A., Jeffries , R. D., Mamajek , E. E., & Naylor , T. 2014, in Protostars and Planets VI, ed. H. Beuther , R. S. Klessen , C. P. Dullemond , & T. Henning , 219

  66. [74]

    2018, AAP, 617, A83, 10.1051/0004-6361/201832599

    Varga , J., \'A brah \'a m , P., Chen , L., et al. 2018, AAP, 617, A83, 10.1051/0004-6361/201832599

  67. [75]

    2012, AAP, 543, A162, 10.1051/0004-6361/201218892

    Vural , J., Kreplin , A., Kraus , S., et al. 2012, AAP, 543, A162, 10.1051/0004-6361/201218892

  68. [76]

    M., & Miner , J

    Walter , F. M., & Miner , J. 2005, in ESA Special Publication, Vol. 560, 13th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, ed. F. Favata , G. A. J. Hussain , & B. Battrick , 1021

  69. [77]

    A., Bontemps , S., Schuler , R

    Wilking , B. A., Bontemps , S., Schuler , R. E., Greene , T. P., & Andr \'e , P. 2001, APJ, 551, 357, 10.1086/320067

  70. [78]

    L., Acton , D

    Wizinowich , P. L., Acton , D. S., Lai , O., et al. 2000, in Adaptive Optical Systems Technology, Vol. 4007, 2--13

  71. [79]

    Yudin , R. V. 2000, AAPS, 144, 285, 10.1051/aas:2000343

Pith tools

Reviewed August 14, 2026 · model on record in the stance chip above.