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C and N abundances in globular clusters. I. The case of 47 Tuc and the effect of the first dredge-up

T0 review · 3 major / 4 minor · reviewed 2026-08-07 · deepseek-v4-flash

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Pith's one-line read Surface carbon and nitrogen in 47 Tuc are not fixed: the first dredge-up shifts the C/N anti-correlation on the sub-giant branch, and the cluster's V vs. V-I CMD therefore needs two isochrones.

desk verdict Valuable homogeneous C/N dataset and a plausible SGB transition, but the N decrease is not yet secure and the two-isochrone parameters are fragile. read the letter →

arxiv 2506.11278 v1 pith:F2UXDUPK submitted 2025-06-12 astro-ph.GA

S. Villanova , L. Monaco , Y. Momany , A. Plotnikova , I. Ordenes This is my paper
classification astro-ph.GA
keywords globularclusters47TucanaeNGC104multiplestellarpopulationsC/Nanti-correlationfirstdredge-upisochronefittingcolor-magnitudediagram
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

Using spectra of 47 Tucanae (NGC 104) from the main sequence to the asymptotic giant branch, this paper measures carbon from the CH G-band and nitrogen from CN bands to show that the C/N anti-correlation is not a fixed population fingerprint. As stars cross the sub-giant branch, the first dredge-up lowers surface [C/Fe] by 0.15-0.20 dex and [N/Fe] by about 0.1 dex while iron stays constant. If this is right, surface C and N abundances of red giants and later phases do not record birth composition, so population tagging with C and N must be done on main-sequence or early sub-giant stars. The paper also finds first- and second-generation stars occupy distinct loci in the optical V vs. V-I CMD, requiring two isochrones: the second generation is about 0.15 dex lower in [M/H], enhanced in helium by $\Delta Y \approx 0.025$, and possibly about 1 Gyr older.

What carries the argument

The load-bearing object is the [N/Fe] vs. [C/Fe] anti-correlation, measured by synthetic-spectrum fitting of the CH G-band for carbon and of CN bands (the near-UV 3845-3885 Å band for MS stars, the 4214-4216 Å band for evolved stars) for nitrogen, with atmospheric parameters derived homogeneously from photometry. The mechanism that carries the abundance part of the argument is the first dredge-up, identified with a narrow 'abundance-changing region' on the SGB; the mechanism that carries the CMD part is a double-isochrone fit in the BASTI database, which allows helium to vary, compared against Hess-diagram residuals between the full field and the outer, first-generation-dominated region.

What would settle it

Measure iron-line abundances directly in the same first- and second-generation red giants that define the RGB split: the two-isochrone model predicts the second generation should show about 0.15 dex lower [Fe/H], but the current analysis assumes a single [Fe/H] = -0.70 for all targets, so finding no systematic iron difference would rule out the lower-metallicity interpretation.

Watch

Extended reading notes

Core claim

The paper's central claim is that the C/N anti-correlation in 47 Tuc shifts at a well-defined place on the sub-giant branch, between $V-I = 0.77$ and $0.85$, because the first dredge-up — the deepening of the convective envelope that mixes processed material to the surface — changes the surface composition of low-mass stars. The observed drop is about $-0.14$ dex in [C/Fe] for the first generation and $-0.21$ dex for the second, with [N/Fe] falling by about 0.1 dex, and [Fe/H] shows no change across the same region. In parallel, the paper demonstrates that the $\sim 0.03$ mag blueward shift of the second-generation red giant branch in the V vs. V-I CMD is not differential reddening and not a simple C,N,O or helium opacity effect, and interprets it as a lower global metallicity. A proper CMD fit then requires two isochrones with different helium content, metallicity, and possibly age, rather than the single isochrone usually assumed for optical CMDs.

Load-bearing premise

The conclusion that the second generation is 0.15 dex more metal-poor and 0.025 helium-richer rests on the assumption that the ~0.03 magnitude blueward shift of the second-generation red giant branch is caused by a lower global metallicity [$M/H$] rather than by an age spread, combined CNO opacity effects, or a deficiency in the model isochrones.

Editorial extensions

If this is right

  • Stars on the RGB, HB, and AGB no longer carry their birth C and N: their measured abundances must be corrected for the first dredge-up before being used to assign them to a stellar population.
  • The abundance-changing region is pinned to the CMD at $V-I$ between 0.77 and 0.85 on the SGB of 47 Tuc, giving a concrete locus where population-tagging abundances change.
  • A single isochrone cannot fit the V vs. V-I CMD of 47 Tuc; the second generation requires $[M/H] = -0.85$, $Y = 0.275$, and possibly age 14 Gyr against first-generation values of $-0.70$, $0.25$, and 13 Gyr.
  • Cluster parameters like age, distance, and reddening derived from optical CMDs of globular clusters can be biased if the two-population structure is ignored.
  • The two populations are spatially segregated, with the second generation more centrally concentrated and the first generation dominant beyond 15 arcminutes, so the choice of radial aperture affects which population dominates any abundance or CMD analysis.

Reading between the lines

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

  • If the nitrogen decrease at the first dredge-up holds in other clusters, large C,N surveys of red giants will need a phase-dependent correction rather than a single offset to recover birth abundances.
  • Applying the same double-isochrone test to other massive globulars would show whether 'second generation more metal-poor and helium-richer' is a general pattern or a peculiarity of 47 Tuc.
  • Other clusters with both main-sequence and giant-branch C,N abundances could be checked for the same sub-giant-branch shift; if the shift is universal, the first-dredge-up correction becomes a standard step in abundance-based population tagging.
  • A direct iron measurement in the split RGB stars is the cleanest way to test the lower-metallicity interpretation, since the analysis currently assumes one [Fe/H] for all targets.
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Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 4 minor

Summary. The paper analyzes the V vs. V-I color-magnitude diagram of the globular cluster 47 Tuc and spectroscopic measurements of [C/Fe] and [N/Fe] for stars from the main sequence to the asymptotic giant branch, using FORS2 low-resolution spectra for MS/SGB stars and GIRAFFE medium/high-resolution spectra for SGB/RGB/HB/AGB stars. The authors identify first- and second-generation stars from a [N/Fe] threshold, find that FG and SG stars occupy distinct loci in the CMD, and conclude that the C/N anticorrelation shifts during the sub-giant branch phase because the first dredge-up decreases C by roughly 0.15-0.20 dex and N by about 0.1 dex. They further argue that a proper fit of the 47 Tuc CMD requires two isochrones with different [M/H], helium content, and possibly age, with the SG being more metal-poor by 0.15 dex and He-richer by about 0.025 in Y.

Significance. If the evolutionary interpretation is correct, the paper has two important implications: surface C and N abundances cannot be treated as birth abundances for stars that have passed the SGB, and optical CMD fitting of globular clusters with a single isochrone may be systematically biased when multiple populations are present. The study benefits from a large sample spanning all evolutionary phases, homogeneous photometric parameter determination, propagated error estimates, and explicit checks for some systematic effects (e.g., a narrower CH band test for C in MS stars). The C/N anticorrelation in this cluster is clearly detected, and the spatial segregation of FG and SG stars is a useful observational constraint. However, the quantitative claims about the N decrease and the differential isochrone parameters are not yet secured to the level required by the paper's central conclusions.

major comments (3)
  1. [Sec. 3, Table 2, and Sec. 6] The claimed N decrease of about 0.10-0.12 dex (Table 5) rests entirely on two different CN diagnostics with no cross-calibrated stars: the UV CN band at 3845-3885 Å in FORS2 R=815 spectra for MS/SGB stars and the 4215 Å CN band in GIRAFFE R=6000-24000 spectra for SGB/RGB/HB/AGB stars. The quoted internal errors on [N/Fe] are 0.08-0.11 dex (Table 4), so the signal is comparable to the noise and to plausible band-to-band, resolution-dependent systematics. The overlap of SG MS and SG SGB points in Fig. 14 is suggestive but does not calibrate the FG stars, which anchor the apparent decline; a zero-point shift of only ~0.1 dex between the two N diagnostics would erase the claimed FG N decrease. To make the first-dredge-up conclusion load-bearing, the authors need either stars observed with both setups, a synthetic-spectrum test of the two bands under the same atmospheric models, or a convincing external calibration.
  2. [Sec. 4, Fig. 9] The differential isochrone parameters ([M/H] difference of 0.15 dex, Y difference of 0.025, and age difference of 1 Gyr) are obtained by eye from a comparison of Hess-diagram residuals, with no quantitative fit statistic, no grid search, and no explicit treatment of degeneracies. The interpretation that the SG RGB is bluer because of a lower global metallicity rather than an age spread, combined CNO opacity effects, or deficiencies in the BASTI isochrones is asserted rather than tested. Since these parameters are then used to apply +60 K temperature corrections to SG stars (Sec. 5), systematic errors in the isochrone assumptions propagate directly into the final abundances. The authors should provide a quantitative fitting procedure or, at minimum, demonstrate that the adopted [M/H], Y, and age differences are uniquely required by the data.
  3. [Sec. 6, Fig. 15 and Table 5] The mean abundances used to trace the C and N decline are computed from different stars in each phase, and the paper explicitly acknowledges that low-N FG SGB stars are missing from the sample (the mean FG SGB [N/Fe] is higher than the evolved FG value because of this selection effect). This means the apparent N decrease for FG stars relies on comparing MS stars to RGB/HB/AGB stars without demonstrating that the spectroscopic samples are unbiased with respect to C and N content. The authors should quantify the impact of the acknowledged selection cuts on the derived mean abundances, for example by simulating the selection function on the CMD and showing the resulting bias on [C/Fe] and [N/Fe] is smaller than the claimed evolutionary changes.
minor comments (4)
  1. [Table 3 footnote] The note says 'Gen. indicates if the target belong to the FG or to the FG'; the second occurrence should read 'SG'.
  2. [Sec. 3] The text 'CN band at 4214-4126 Å' appears to be a typo for the range 4214-4216 Å listed in Table 2.
  3. [Sec. 5] The description of the gravity correction to V-I colors would benefit from stating explicitly that the corrections are applied only to MS and SGB targets, as implied by Fig. 12, rather than to the full sample.
  4. [Sec. 6] The statements about 'abundance changing region' between Dist.=2.82 and 2.93 would be easier to interpret if the corresponding V magnitude or log(g) values were given, in addition to the V-I color range.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the C and N abundances are measured from spectra, the C/N evolution is not generated by the isochrone fit, and no load-bearing self-citation or imported uniqueness theorem is used. The N-specific drop is weakened by the absence of cross-calibrated stars between the two CN diagnostics, but that is a robustness concern, not circularity.

full rationale

The central derivation chain is not circular. [C/Fe] and [N/Fe] are obtained by spectral synthesis of the CH G-band and the CN bands (Table 2, Fig. 3), not from the photometric isochrone fit; the first analysis, which uses a single Padova isochrone for the stellar parameters, already shows the MS/SGB/RGB separation in the [N/Fe]–[C/Fe] plane (Fig. 4) and the C/N offset between unevolved and evolved stars that underlies the first-dredge-up claim. The FG/SG division by [N/Fe] = 0.20 is a labeling convention; the CMD dichotomy it is used to visualize is independently present in the photometry (Figs. 2, 8, 9), so the two-isochrone conclusion is not forced by the abundance definition. The isochrone-based +60 K Teff corrections for SG RGB/MS stars feed back into the final abundances, but they are applied within populations, and the abundance drop is already present before these corrections are applied; this is therefore an iterative parameter refinement rather than a prediction identical to its input. The [M/H], Y, and age differences are fitting results, and the paper does not present them as independent first-principles predictions. The weakest point is not circularity but calibration: the N drop near the SGB relies on comparing the FORS2 UV CN band (3845–3885 Å) with the GIRAFFE CN band at 4215 Å, and the paper explicitly states there are no stars in common to verify this zero point; this is an important systematic-error concern for the N-specific part of the claim, but it does not make the derivation circular. No load-bearing self-citation or imported uniqueness theorem is used; the cited dredge-up predictions (Vincenzo et al. 2021; Salaris et al. 2020) are external and are used as a comparison rather than as the source of the measured trend.

Assumptions & free parameters 7 free parameters · 6 assumptions · 0 invented entities

No new particles, forces, dimensions, or physical entities are introduced. The 'abundance changing region' is a descriptive label for a position on the SGB, not a postulated object.

free parameters (7)
  • Delta [M/H] between FG and SG = 0.15 dex (-0.70 vs -0.85)
    Chosen by fitting BASTI isochrones to the RGB color separation in the Hess diagram; not measured from spectra.
  • Delta Y between FG and SG = 0.025 (0.25 vs 0.275)
    Adjusted to reproduce lower RGB and MS shapes; differential uncertainty quoted at 0.01.
  • Delta Age between FG and SG = 1 Gyr (13 vs 14 Gyr)
    Set to match the SG turnoff color; differential uncertainty about 1 Gyr.
  • Distance modulus and reddening = (m-M)V=13.24, E(V-I)=0.025
    Fit to the outer field isochrone; systematic uncertainties 0.10 mag and 0.01 mag.
  • Assumed [Fe/H] = -0.70 (Harris 2010)
    Used in all atmospheric models and syntheses; the measured SGB mean is -0.73, so the assumption is approximately right but not tailored per star.
  • FG/SG [N/Fe] threshold = +0.20 dex
    Hand-chosen division between first and second generation in the N-C plane.
  • Teff correction for single SG MS and RGB stars = +60 K
    Based on the mean temperature difference between the two fitted isochrones; affects [C/Fe] and [N/Fe] by about 0.04-0.06 dex.
assumptions (6)
  • domain assumption V-I color depends only on effective temperature, not on metallicity (Alonso et al. 1999).
    Used in Section 3 to assign Teff from photometry and in Section 4 to argue that the bluer SG RGB implies higher temperature rather than a color-metallicity effect. If false, the two-isochrone interpretation weakens.
  • domain assumption The Padova and BASTI isochrone sets capture the relevant stellar physics, including the response of RGB color to [M/H] and Y.
    Used in Section 4 for both the single and double isochrone fits. The two databases require different [M/H] and age for the same FG population, showing model sensitivity.
  • domain assumption The Salaris et al. (2020) first dredge-up model is the correct reference for the expected N change.
    Section 6 compares the measured N drop with two models; Vincenzo et al. (2021) predicts N enhancement while Salaris et al. (2020) predicts a drop, and the paper adopts the latter. The FDU attribution depends on this choice.
  • domain assumption No significant differential reddening affects the CMD.
    Section 4 uses low E(B-V), a KS test of spatial distributions, and a consistency argument between color and magnitude spreads to rule it out. If wrong, the FG/SG color split could be a reddening artifact.
  • ad hoc to paper SG MS stars that fall on the FG isochrone are binary systems.
    Section 5, Figure 11: the paper reclassifies a subset of SG MS targets as binaries without radial-velocity or binarity evidence, which justifies leaving their Teff uncorrected and narrows the MS anticorrelation.
  • standard math The spectral synthesis codes (ATLAS9, SPECTRUM) and molecular linelists reproduce CH and CN features accurately.
    Section 3: C and N abundances are derived by matching synthetic spectra; no benchmark validation against standard stars is given in this paper.

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Pith. "Pith review of C and N abundances in globular clusters. I. The case of 47 Tuc and the effect of the first dredge-up." pith.science (2026). https://pith.science/paper/F2UXDUPK

@misc{pith2026250611278,
  author       = {Pith},
  title        = {Pith review of: C and N abundances in globular clusters. I. The case of 47 Tuc and the effect of the first dredge-up},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/F2UXDUPK}},
  note         = {Machine review of arXiv:2506.11278}
}
read the original abstract

Globular clusters exhibit star-to-star chemical variations, traceable through both photometric and spectroscopic data. In this study, we investigate chemical variations in the globular cluster NGC104 (47Tucanae), aiming to trace multiple stellar populations across evolutionary phases and examine how the C/N anti-correlation evolves from the main sequence (MS) to the asymptotic giant branch (AGB). We also assess the impact of these populations on the interpretation of the V vs. V-I diagram. [C/Fe] and [N/Fe] abundances are obtained from CN and the CH features, while atmospheric parameters are homogeneously derived from photometry. The inferred abundances allow us to disentangle multiple populations along the CMD and refine cluster parameters. We find that MS stars are more C- and N-rich than their red giant branch, horizontal branch, and AGB counterparts. The C/N anti-correlation shifts during the sub-giant branch phase, coinciding with the first dredge-up. Interestingly, stars with different C and N abundances occupy distinct regions of the V vs V-I diagram, a pattern not attributable to differential reddening. Proper CMD fitting requires two isochrones with differing helium content, metallicity, and possibly age.

Figures

Figures reproduced from arXiv: 2506.11278 by the authors.

Figure 1
Figure 1. Distribution of NGC 104 member stars in the sky. Blue and red points are stars from ground-based photometry, while black points in the center are stars from the HST Large Legacy Treasury Program. The radial cut at 15’ was used to separate the inner from the outer cluster region. Black circles with colored insets represent MS (magenta), SGB (yellow), RGB (green), HB (cyan) and AGB (black) targets. See text for more d… view at source ↗
Figure 3
Figure 3. Example of spectrosynthesis. Panels on the left show the synthesis for C while panels on the right show the synthesis for N. Upper row shows the synthesis for the MS target #1_13, middle row shows synthesis for the HB target #RHB_I_a_40848, while the lower row shows the synthesis for the SGB target N104e_51104. The wavelength range used for the abundance determination is shown as a shaded region. Observed spectra ar… view at source ↗
Figure 4
Figure 4. [N/Fe] vs. [C/Fe] anticorrelation as obtained from the first abun￾dance determination run. The red line divides MS targets on the right from RGB/HB/AGB targets on the left. SGB targets are located on both sides of the red line. The black line divides FG from SG stars. Red ar￾rows indicate stars for which Marino et al. (2016) gives no [N/Fe]. For these stars we assumed [N/Fe]=0.0 as an upper limit. See text for more … view at source ↗
Figures from the paper (8 more)
Figure 6
Figure 6. Figure 6: Histogram distribution and cumulative distribution of FG (red) and SG (blue) RGB stars. Histograms and cumulative curves from r=0’and r=3’ were obtained from the HST photometry (upper panel), while those from r∼2’ to r=30’ were obtained from the ground-based photometry…
Figure 7
Figure 7. Figure 7: V vs. V-I CMD of the outer part of the cluster (r>15´). The blue line is the same best fitting isochrone shown in figure 2. The parameters of the fitting are reported. See text for more details. we have to use Y>0.40 for the second generation, a helium abun￾dance never…
Figure 9
Figure 9. Figure 9: figure 9. The main di [PITH_FULL_IMAGE:figures/full_fig_p008_9.png]
Figure 9
Figure 9. Figure 9: Difference between the Hess diagrams of the full photome￾try (see figure 2) and the outer part (r>15’) photometry (see figure 7). The blue line is the same best fitting isochrone shown in figure 2, while the red curved is the BASTI isochrone that bast matches the Padov…
Figure 11
Figure 11. Figure 11: CMD position of our SG MS and SGB targets. Isochrones are those described in figure 9. Targets highlighted by a magenta square are those considered as binaries. See text for more details. the best temperature estimation possible, we have to treat single and binary SG …
Figure 13
Figure 13. Figure 13: The log(g) vs. Te f f for our targets. The continuos black lines represents the isochrones we used to obtain the initial stellar parame￾ters (see fig 2). The shaded black lines is an isochrone from the same database but with a global metallicity 0.15 dex lower. Red ci…
Figure 14
Figure 14. Figure 14: The final [N/Fe] vs [C/Fe] anticorrelation we obtained for our targets. Magenta, yellow, green, cyan and black symbols represents MS, SGB, RGB, HB and AGB targets respectively. Mean values for FG and SG stars are indicated with crosses surrounded by black circles. The…
Figure 16
Figure 16. Figure 16: Upper panel: Distribution on the CMD of FG (red) and SG (blue) SGB targets. The SGB region where abundance change happens is indicated by the two green lines. Middle panel: Abundance variation along the SGB. The y coordinate is the [C/Fe] difference between each targe…

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Reference graph

Works this paper leans on

49 extracted references · 42 canonical work pages · cited by 1 Pith paper

  1. [1]

    & Parisi, C

    Albornoz, A., Villanova, S., Cortes, C.C., Ahumada, J.A. & Parisi, C. 2021, AJ, 161, 76

    work page 2021

  2. [2]

    1999, A&AS, 140, 261

    Alonso, A., Arribas, S., & Martinez-Roger, C. 1999, A&AS, 140, 261

    work page 1999

  3. [3]

    & Guhathakurta, P

    Anderson, J., Piotto, G., King, I.R., Bedin, L.R. & Guhathakurta, P. 2009, ApJ, 697, 58

    work page 2009

  4. [4]

    Bastian, N., Lamers, H. J. G. L. M., de Mink, S. E., Longmore, S. N., Goodwin, S. P., & Gieles, M. 2013, MNRAS, 436, 2398

    work page 2013

  5. [5]

    & Hilker, M

    Baumgardt, H. & Hilker, M. 2018, MNRAS, 478, 1520

    2018

  6. [6]

    2012, MNRAS, 427, 127

    Bressan, A., Marigo, P., Girardi, L., Salasnich, B., Dal Cero, C., Rubele, S., & Nanni, A. 2012, MNRAS, 427, 127

    work page 2012

  7. [7]

    1997, AJ, 114, 1051

    Briley, M. 1997, AJ, 114, 1051

    work page 1997

  8. [8]

    2004, AJ, 127, 1588

    Briley et al. 2004, AJ, 127, 1588

    work page 2004

Show all 49 references
  1. [9]

    G., Lucatello, S., Catanzaro, G., Leone, F., Bellazzini, M., Claudi, R., D'Orazi, V., Momany, Y., Ortolani, S., Pancino, E., Piotto, G., Recio-Blanco, A., Sabbi, E

    Carretta, E., Bragaglia, A., Gratton, R. G., Lucatello, S., Catanzaro, G., Leone, F., Bellazzini, M., Claudi, R., D'Orazi, V., Momany, Y., Ortolani, S., Pancino, E., Piotto, G., Recio-Blanco, A., Sabbi, E. 2009, A&A, 505, 117

    2009

  2. [10]

    2016, A&A 595, 1

    The Gaia mission. 2016, A&A 595, 1

    2016

  3. [11]

    G., Lucatello, S., Bellazzini, M., Catanzaro, G., Leone, F., Momany, Y., Piotto, G

    Carretta, E., Bragaglia, A., Gratton, R. G., Lucatello, S., Bellazzini, M., Catanzaro, G., Leone, F., Momany, Y., Piotto, G. & D'Orazi, V. 2010, A&A, 520, 95

    2010

  4. [12]

    G., Kirby, E

    Cohen, J. G., Kirby, E. N., Simon, J. D., & Geha, M. 2010, ApJ, 725, 288

    2010

  5. [13]

    P., Marino, A

    D'Antona, F., Vesperini, E., D'Ercole, A., Ventura, P., Milone, A. P., Marino, A. F., & Tailo, M. 2016, MNRAS, 458, 2122

    2016

  6. [14]

    2007, A&A, 464, 1029

    Decressin, T., Meynet, G., Charbonnel, C., Prantzos, N., & Ekstrom, S. 2007, A&A, 464, 1029

    2007

  7. [15]

    E., Pols, O

    de Mink, S. E., Pols, O. R., Langer, N., & Izzard, R. G. 2009, A&A, 507, 1

    2009

  8. [16]

    Summary of the content and survey properties

    Gaia Data Release 3. Summary of the content and survey properties. 2023, A&A, 674, 1

    2023

  9. [17]

    & Santander, T.A

    Geisler, D., Villanova, S., O'Connell, J.E., Cohen, R.E., Moni Bidin, C., Fernández-Trincado, J.G., Muñoz, C., Minniti, D., Zoccali, M., Rojas-Arriagada, A., Contreras Ramos, R., Catelan, M., Mauro, F., Cortes, C., Ferreira Lopes, C.E., Arentsen, A., Starkenburg, E., Martin, N...

    2021

  10. [18]

    2010, arXiv1012.3224H

    Harris, W.E. 2010, arXiv1012.3224H

    2010 arXiv

  11. [19]

    Kurucz 1970, SAOSR 309

    1970

  12. [20]

    Majewski, S.R., Schiavon, R.P., Frinchaboy, P.M. et al. 2017, AJ, 154, 94

    2017

  13. [21]

    Marin-Franch, A., Aparicio, A., Piotto, G. et al. 2009, ApJ, 694, 1498

    2009

  14. [22]

    2009, A&A, 505, 1099

    Marino, A.F., Milone, A.P., Piotto, G., Villanova, S., Bedin, L.R., Bellini, A., & Renzini, A. 2009, A&A, 505, 1099

    2009

  15. [23]

    & Sbordone, L

    Marino, A.F., Milone, A.P., Casagrande, L., Collet, R., Dotter, A., Johnson, C.I., Lind, K., Bedin, L.R., Jerjen, H., Aparicio, A. & Sbordone, L. 2016, MNRAS, 459, 610

    2016

  16. [24]

    R., Origlia, L., Rich, R

    Massari, D., Mucciarelli, A., Ferraro, F. R., Origlia, L., Rich, R. M., Lanzoni, B., Dalessandro, E., Valenti, E., Ibata, R., Lovisi, L., et al. 2014, ApJ, 795, 22

    2014

  17. [25]

    & Siegel, M

    Milone, A.P., Bedin, L.R., Piotto, G., Anderson, J., King, I.R., Sarajedini, A., Dotter, A., Chaboyer, B., Marín-Franch, A., Majewski, S., Aparicio, A., Hempel, M., Paust, N.E.Q., Reid, I.N., Rosenberg, A. & Siegel, M. 2008, ApJ, 673, 241

    2008

  18. [26]

    Milone, A.P., Piotto, G., Bedin, L.R. et al. 2012, ApJ, 744, 58

    2012

  19. [27]

    & van der Marel, R

    Milone, A.P., Piotto, G., Renzini, A., Marino, A.F., Bedin, L.R., Vesperini, E., D'Antona, F., Nardiello, D., Anderson, J., King, I.R., Yong, D., Bellini, A., Aparicio, A., Barbuy, B., Brown, T.M., Cassisi, S., Ortolani, S., Salaris, M., Sarajedini, A. & van der Marel, R. P. 2...

    2017

  20. [28]

    & Strassmeier, K.G

    Mott A., Steffen, M., Caffau, E. & Strassmeier, K.G. 2020, A&A, 638, 58

    2020

  21. [29]

    & Munari, U

    Moro, D. & Munari, U. 2000, A&AS, 147, 361

    2000

  22. [30]

    R., Cassisi, S., Granata, V., King, I

    Nardiello, D., Libralato, M., Piotto, G., Anderson, J., Bellini, A., Aparicio, A., Bedin, L. R., Cassisi, S., Granata, V., King, I. R., Lucertini, F., Marino, A.F., Milone, A.P., Ortolani, S., Platais, I., & van der Marel, R. P. 2018, MNRAS, 481, 3382

    2018

  23. [31]

    & Freeman, K

    Norris, J. & Freeman, K. C. 1982, ApJ, 254, 143

    1982

  24. [32]

    & Ferguson, J.W

    Pietrinferni, A., Hidalgo, S., Cassisi, S., Salaris, M., Savino, A., Mucciarelli, A., Verma, K., Silva A.V., Aparicio, A. & Ferguson, J.W. 2021, ApJ, 908, 102

    2021

  25. [33]

    Pancino, E., Romano, D., Tang, B. et al. 2017, A&A, 601, 112

    2017

  26. [34]

    Pancino, E., Zocchi, A., Rainer, M. et al. 2024, A&A, 686, 283

    2024

  27. [35]

    & Renzini, A

    Piotto, G., Bedin, L.R., Anderson, J., King, I.R., Cassisi, S., Milone, A.P., Villanova, S., Pietrinferni, A. & Renzini, A. 2007, ApJ, 661, 53

    2007

  28. [36]

    & Zoccali, M

    Piotto, G., Milone, A.P., Bedin, L.R., Anderson, J., King, I.R., Marino, A.F., Nardiello, D., Aparicio, A., Barbuy, B., Bellini, A., Brown, T.M., Cassisi, S., Cool, A.M., Cunial, A., Dalessandro, E., D'Antona, F., Ferraro, F.R., Hidalgo, S., Lanzoni, B., Monelli, M., Ortolani,...

    2015

  29. [37]

    2015, AJ, 149, 91

    Piotto G., Milone, A.P., Bedin, L.R., Anderson, J., King, I.R., Marino, A.F., Nardiello, D., Aparicio, a., Barbuy, B., & Bellini, A. 2015, AJ, 149, 91

    2015

  30. [38]

    R., Milone, A

    Renzini, A., D'Antona, F.,Cassisi, S., King, I. R., Milone, A. P., Ventura, P., Anderson, J., Bedin, L.R., Bellini, A., Brown, T.M., Piotto, G., van der Marel, R.P., Barbuy, B., Dalessandro, E., Hidalgo, S., Marino, A. F., Ortolani, S., Salaris, M. & Sarajedini, A. 2015, MNRAS...

    2015

  31. [39]

    & Pietrinferni, A

    Salaris, M., Cassisi, S. & Pietrinferni, A. 2016, A&A, 590, 64

    2016

  32. [40]

    & Lardo, Carmela 2020, MNRAS, 492, 3

    Salaris, M., Usher, C., Martocchia, S., Dalessandro, E., Bastian, N., Saracino, S., Cassisi, S., Cabrera-Ziri, I. & Lardo, Carmela 2020, MNRAS, 492, 3

    2020

  33. [41]

    & Monelli, M

    Stetson, P.B., Pancino, E., Zocchi, A., Sanna, N. & Monelli, M. 2019, MNRAS, 485, 3042

    2019

  34. [42]

    Villanova, S., Geisler, D., Carraro, G., Moni Bidin, & C., Muñoz, 2013, ApJ, 778, 186

    2013

  35. [43]

    G., & Cassisi, S

    Villanova, S., Geisler, D., Gratton, R. G., & Cassisi, S. 2014, ApJ, 791, 107

    2014

  36. [44]

    & Pinsonneault, M.H

    Vincenzo, F., Weinberg, D.H., Montalban, J., Miglio, A., Khan, S., Grith, E.J., Hasselquist, S., Johnson, J.W., Johnson, J.A., Nitschelm, C. & Pinsonneault, M.H. 2021, arXiv210603912V => arXiv: 21060.3912

    2021

  37. [45]

    , " * 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.sent...

  38. [46]

    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 gl...

  39. [47]

    @esa (Ref

    \@ifclassloaded agu2001 natbib The agu2001 class already includes natbib coding, so you should not add it explicitly Type <Return> for now, but then later remove the command natbib from the document \@ifclassloaded aguplus natbib The aguplus class already includes natbib codin...

  40. [48]

    @stdbsttrue NAT@ctr \@lbibitem[ NAT@ctr ] \@lbibitem[#1]#2 \@extra@b@citeb \@ifundefined br@#2\@extra@b@citeb \@namedef br@#2 \@nameuse br@#2\@extra@b@citeb \@ifundefined b@#2\@extra@b@citeb @num @parse #2 [ @natanchorstart #2\@extra@b@citeb \@biblabel @num @natanchorend] @ifc...

  41. [49]

    C*Ò<q =V= Ǫ gNԅ B'Lf BAA K = ܠG E . _/?z ,-3̹AGf2 ? -ϰ< @ d

    @open @close @open @close and [1] URL: #1 \@ifundefined chapter * \@mkboth \@ifundefined NAT@sectionbib * \@mkboth * \@mkboth\@gobbletwo \@ifclassloaded amsart * \@ifclassloaded amsbook * \@ifundefined bib@heading @heading NAT@ctr thebibliography [1] @ \@biblabel NAT@ctr \@bib...

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