J/A+A/708/A216 C-MetaLL survey. IX. Cepheid data (Ripepi+, 2026)
Cepheid Metallicity in the Leavitt Law (C-MetaLL) survey.
IX. Metallicity dependence of Period-Wesenheit relations based on a homogeneous
spectroscopic sample.
Ripepi V., Trentin E., Catanzaro G., Marconi M., Bhardwaj A., Clementini G.,
Cusano F., De Somma G., Molinaro R., Sicignano T., Storm J.
<Astron. Astrophys. 708, A216 (2026)>
=2026A&A...708A.216R 2026A&A...708A.216R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Stars, distances ; Photometry ; Spectroscopy ;
Abundances, [Fe/H]
Keywords: stars: abundances - stars: distances - stars: fundamental parameters -
stars: variables: Cepheids - distance scale
Abstract:
The C-MetaLL project has provided homogeneous spectroscopic abundances
of 290 Classical Cepheids (DCEPs) for which we have the
intensity-averaged magnitudes in multiple optical and near-infrared
(NIR) bands, periods, pulsation modes, and Gaia parallaxes corrected
for individual zero-point (ZP) biases.
Our goal is to derive updated period-Wesenheit-metallicity (PWZ)
relations using the largest and most homogeneous metallicity sample
ever used for such analyses, covering a range of -1.3<[Fe/H]<+0.3dex,
and to assess the metallicity dependence of these relations.
We computed several optical and NIR Wesenheit magnitudes adopting both
Cardelli et al. and Fitzpatrick reddening laws, and transformed
Johnson-Cousins Wesenheit magnitudes into their HST equivalents using
empirical relations. Using 275 DCEPs with reliable parallaxes, we
applied a robust photometric parallax technique, which simultaneously
fits all parameters --- including the global ZP counter-correction to
Gaia parallaxes --- and handles outliers via a Cauchy likelihood to
account for the sample's excess variance.
We find a stronger metallicity dependence (gamma~-0.5mag/dex in
optical, ~-0.4mag/dex in NIR) than recent literature reports. Gaia
parallax ZP counter-correction epsilon varies smoothly across bands,
with an average value of ∼10 muas, aligning with previous
determinations. Applying our PWZ relations to ∼4500 LMC Cepheids
yields distances generally consistent within 1 sigma with geometric
estimates. The choice of reddening law has a small impact, while using
only fundamental-mode pulsators significantly increases the
uncertainties. Including alpha-element corrections increases
abs(gamma) and reduces epsilon. However, we find 1 sigma consistency
gamma values with the literature, particularly for the Wesenheit
magnitude in the HST bands, by restricting the sample to brighter
(i.e. closer) objects, or by including only pulsators with
-0.7<[Fe/H]<0.2dex. Our results hint at a large gamma or a non-linear
dependence on metallicity of DCEP luminosities at the metal-poor end,
which is difficult to quantify with the precision of parallaxes of the
present dataset.
Description:
This table lists the astrometric, photometric and spectroscopic data
for 290 Galactic Classical Cepheids used in this paper. This data can
be used to reproduce the results.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 283 290 Astrometric, photometric and spectroscopic data
for 290 Galactic Classical Cepheids used in
this paper
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See also:
J/MNRAS/508/4047 : 47 classical Cepheids HARPSN@TNG spectroscopy
(Ripepi+, 2021)
J/A+A/681/A65 : Cepheids PL relation metallicity dependence (Trentin+, 2024)
J/A+A/683/A234 : Cepheid Metallicity in the Leavitt Law Survey
(Bhardwaj+, 2024)
J/A+A/690/A246 : Cepheid radial abundance gradients (Trentin+, 2024)
J/A+A/706/A225 : 23 Classical Cepheids abundances (Catanzaro+, 2026)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 28 A28 --- Star Common name of the Star
30- 48 I19 --- GaiaDR3 Gaia DR3 source identification
50- 58 F9.5 deg RAdeg Right ascension (ICRS) at Epoch=2000
60- 68 F9.5 deg DEdeg Declination (ICRS) at Epoch=2000
70- 77 F8.5 d P Period
79- 86 F8.5 d Pfund Fundamentalised period
88- 91 A4 --- Mode Mode of pulsation (1)
93- 98 F6.3 mag Gmag Magnitude in the G band
100-104 F5.3 mag e_Gmag Error on the G magnitude
106-111 F6.3 mag BPmag Magnitude in the BP band
113-117 F5.3 mag e_BPmag Error on the BP magnitude
119-124 F6.3 mag RPmag Magnitude in the RP band
126-130 F5.3 mag e_RPmag Error on the RP magnitude
132-137 F6.3 mag Vmag Magnitude in the V band
139-143 F5.3 mag e_Vmag Error on the V magnitude
145-150 F6.3 mag Imag Magnitude in the I band
152-156 F5.3 mag e_Imag Error on the I magnitude
158-163 F6.3 mag Jmag Magnitude in the J band
165-169 F5.3 mag e_Jmag Error on the J magnitude
171-176 F6.3 mag Hmag Magnitude in the H band
178-182 F5.3 mag e_Hmag Error on the H magnitude
184-189 F6.3 mag Ksmag Magnitude in the Ks band
191-195 F5.3 mag e_Ksmag Error on the Ks magnitude
197-201 F5.2 --- [Fe/H] Iron abundance
203-206 F4.2 --- e_[Fe/H] Error on the iron abundance
208-212 F5.2 --- [alpha/Fe] alpha over iron abundance
214-217 F4.2 --- e_[alpha/Fe] Error on alpha over iron abundance
219-225 F7.4 mas Plx Gaia parallax
227-232 F6.4 mas e_Plx Error on the Gaia parallax
234-242 E9.1 mas corPlx Corrected Gaia parallax
244-249 F6.2 --- gof Goodness-of-Fit of the astrometric
solution (astrometricgofal)
251-256 F6.3 --- ruwe Re-normalised Unit Weight Error
258-264 A7 --- flagSource Flag identification/Gaia photometry (2)
266-278 A13 --- flagOptNir Flag photometry (3)
280-283 A4 --- flagMet Flag metallicity (4)
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Note (1): Cepheid mode or class as follows:
DCEP_F = Classical Cepheids pulsating in the fundamental mode
DCEP_1O = Classical Cepheids pulsating in the first overtone mode
DCEP_F1O = Classical Cepheids pulsating in both fundamental and
first overtone modes
DCEP_1O2O = Classical Cepheids pulsating in both first and
second overtone modes
Note (2): Flag indicating the source of the identification of the DCEP and the
used pulsation period (left) and source of the Gaia photometry
(right). For the meaning of the acronyms see the references below.
Note (3): Flag indicating the source of the V (left), I (middle) and
J,H,Ks (right) photometry. P22 indicates magnitudes calculated
on the basis of the Gaia bands using the transformations
to the Johnson-Cousins system by Pancino et al. (2022).
2MASS denotes magnitudes calculated in this work based
on the 2MASS survey data.
For the meaning of the other acronyms see the references below.
Note (4): Flag indicating the source of the iron abundance. For the meaning
of the acronyms see the references below.
P21 = Pietrukowicz et al., 2021AcA....71..205P 2021AcA....71..205P, See Cat. J/AcA/69/305
SOS = Ripepi et al.. 2023A&A...674A..17R 2023A&A...674A..17R, Cat. J/A+A/674/A17)
DR3 = Gaia Collaboration, Vallenari et al., 2023A&A...674A...1G 2023A&A...674A...1G
B15 = Bhardwaj et al., 2015MNRAS.447.3342B 2015MNRAS.447.3342B, J/MNRAS/447/3342
G18 = Groenewegen, 2018A&A...619A...8G 2018A&A...619A...8G, Cat. J/A+A/619/A8
P22 = Pancino et al., 2022A&A...664A.109P 2022A&A...664A.109P, Cat. J/A+A/664/A109
B24 = Bhardwaj et al., 2024A&A...683A.234B 2024A&A...683A.234B, Cat. J/A+A/683/A234
2MASS = Skrutskie et al., 2006AJ....131.1163S 2006AJ....131.1163S, Cat. VII/233
G20 = Catanzaro et al., 2020A&A...639L...4C 2020A&A...639L...4C
R21a = Ripepi et al., 2021MNRAS.508.4047R 2021MNRAS.508.4047R, Cat. J/MNRAS/508/4047
R21b = Ripepi et al., 2021A&A...647A.111R 2021A&A...647A.111R
T23 = Trentin et al., 2023MNRAS.519.2331T 2023MNRAS.519.2331T
T24b = Trentin et al., 2024A&A...681A..65T 2024A&A...681A..65T, Cat. J/A+A/681/A65
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Acknowledgements:
Vincenzo Ripepi, vincenzo.ripepi(at)inaf.it
References:
Ripepi et al., Paper I 2021MNRAS.508.4047R 2021MNRAS.508.4047R, Cat. J/MNRAS/508/4047
Trentin et al., Paper II 2023MNRAS.519.2331T 2023MNRAS.519.2331T
Molinaro et al., Paper III 2023MNRAS.520.4154M 2023MNRAS.520.4154M
Trentin et al., Paper IV 2024A&A...681A..65T 2024A&A...681A..65T, Cat. J/A+A/681/A65
Bhardwaj et al., Paper V 2024A&A...683A.234B 2024A&A...683A.234B
Trentin et al., Paper VI 2024A&A...690A.246T 2024A&A...690A.246T, Cat. J/A+A/690/A246
Catanzaro et al., Paper VII 2026A&A...706A.225C 2026A&A...706A.225C, Cat. J/A+A/706/A225
(End) Patricia Vannier CDS 16-Feb-2026