J/A+A/703/A175 Updated calibrations of Galactic O-type stars (Holgado+ 2025)
The IACOB project.
XV. Updated calibrations of fundamental parameters of Galactic O-type stars.
Holgado G., Simon-Diaz S., Herrero A.
<Astron. Astrophys. 703, A175 (2025)>
=2025A&A...703A.175H 2025A&A...703A.175H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, early-type ; Stars, fundamental ; Spectroscopy ;
Fundamental catalog ; Milky Way
Keywords: techniques: spectroscopic - catalogs - stars: early-type -
stars: fundamental parameters - Galaxy: general
Abstract:
Modern spectroscopic surveys combined with Gaia distances are enabling
reliable estimates of fundamental parameters for hundreds of Galactic
O-type stars and the full range of spectral types and luminosity
classes. Here we provide updated, statistically robust empirical
calibrations of the fundamental parameters of Galactic O-type stars,
as well as of their absolute visual magnitudes (Mv) and bolometric
corrections (BC), based on high-quality observational data. We perform
a homogeneous analysis of a sample of 358 Galactic O-type stars,
combining high-resolution spectroscopy and Gaia distances. A subset of
234 stars meeting strict quality criteria involving parallax,
extinction, and multi-band photometry was used to derive empirical
calibrations of fundamental parameters. For those same stars,
calibrated parameters were estimated from their measured Mv using the
derived relations, allowing us to assess the internal consistency and
predictive power of the calibrations. We present updated
spectral-type-based calibrations of fundamental parameters for
luminosity classes V, III, and I. Compared to previous works, we find
systematic shifts, particularly in effective temperature for dwarfs
and in Mv across all classes, which propagate into derived quantities.
Applying the Mv calibrations to the full sample yields consistent
estimates of radius and luminosity, while spectroscopic mass (Msp)
shows significant scatter. We also evaluate the FW3414 parameter (from
the Hbeta line) as a calibrator for Mv, useful in large surveys
lacking reliable spectral classification. Excluding SB1 systems has a
noticeable impact only on the Msp calibration for LC V. These updated
empirical calibrations offer a robust reference for Galactic O-type
stars and will support studies of massive star populations in both
Galactic and extragalactic contexts, particularly in the era of large
spectroscopic surveys.
Description:
List of the 234 Galactic O-type stars in the curated calibrator sample
with spectroscopic and fundamental parameters available.
Rotation, temperature, and gravity are derived from the analysis of
the spectrum with the best signal-to-noise ratio. The remaining
parameters are obtained by compiling photometry and distance, and
combining all of them to determine the fundamental stellar properties.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tabled1.dat 139 234 Galactic O-type stars calibrator sample with
spectroscopic and fundamental parameters available
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See also:
J/A+A/562/A135 : Northern Galactic OB stars vsini (Simon-Diaz+, 2014)
J/A+A/597/A22 : Massive O- and B-type stars velocities (Simon-Diaz+, 2017)
J/A+A/613/A65 : Spectroscopic parameters of O-type stars (Holgado+, 2018)
J/A+A/613/A9 : Extinction towards Galactic O stars (Maiz Apellaniz+, 2018)
J/A+A/638/A157 : O-type stars near ZAMS elusive detection (Holgado+, 2020)
J/A+A/665/A150 : Rot. properties of Galactic O-type stars (Holgado+ 2022)
Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- ID Star name
13- 28 A16 --- SpType Spectral type (1)
30- 32 A3 --- SBStatus Multi-epoch notes
34- 35 I2 --- Nsp Number of spectra available
37- 39 I3 km/s vsini projected rotational velocity
41- 44 F4.1 kK Teff Effective temperature
46- 48 F3.1 kK e_Teff Effective temperature uncertainty
50- 53 F4.2 [cm/s2] loggc Gravity corrected from rotational effects
55- 58 F4.2 [cm/s2] e_loggc Gravity corrected from rot. uncertainty
60- 65 F6.3 mag Gmagcorr Gaia G magnitude (following Maiz Apellaniz
et al., 2018A&A...619A.180M 2018A&A...619A.180M,
Cat. J/A+A/619/A180)
67- 70 F4.2 mag Av visual extinction in V band
72- 75 F4.2 mag e_Av visual extinction in V band uncertainty
77- 80 I4 pc dALS distance from the ALS catalog (1)
82- 84 I3 pc e_dALS distance from the ALS catalog uncertainty
86- 90 F5.2 mag VMAG Absolute V magnitude
92- 95 F4.2 mag e_VMAG Absolute V magnitude uncertainty
97-100 F4.1 Rsun R Stellar radius
102-104 F3.1 Rsun e_R Stellar radius uncertainty
106-109 F4.2 [Lsun] logL logarithm of stellar luminosity
111-114 F4.2 [Lsun] e_logL logarithm of stellar luminosity uncertainty
116-119 F4.1 Msun Mspc Stellar mass, corrected from
rotational effects
121-124 F4.1 Msun e_Mspc Stellar mass uncertainty
126-130 F5.2 mag BCv Bolometric correction derived from
luminosity
132-135 F4.2 mag e_BCv Bolometric correction uncertainty
137-139 F3.1 10.nm FW3414 EW of Hbeta at 3/4 - EW at 1/4
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Note (1): From the ALS catalog.
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Acknowledgements:
Gonzalo Holgado, gholgado(at)cab.inta-csic.es, gholgado(at)iac.es
References:
Simon-Diaz & Herrero, Paper I 2014A&A...562A.135S 2014A&A...562A.135S, Cat. J/A+A/562/A135
Simon-Diaz et al., Paper II 2014A&A...570L...6S 2014A&A...570L...6S
Simon-Diaz et al., Paper III 2017A&A...597A..22S 2017A&A...597A..22S, Cat, J/A+A/597/A22
Godart et al., Paper IV 2017A&A...597A..23G 2017A&A...597A..23G
Holgado et al., Paper V 2018A&A...613A..65H 2018A&A...613A..65H, Cat. J/A+A/613/A65
Maiz-Apellaniz & Barba, 2018A&A...613A...9M 2018A&A...613A...9M, Cat. J/A+A/613/A9
Pantaleoni Gonzalez et al., 2025MNRAS.tmp.1439G
Holgado et al., Paper VI 2020A&A...638A.157H 2020A&A...638A.157H, Cat. J/A+A/638/A157
Holgado et al., Paper VII 2022A&A...665A.150H 2022A&A...665A.150H
Britavskiy et al., Paper VIII 2023A&A...672A..22B 2023A&A...672A..22B
de Burgos et al., Paper IX 2023A&A...674A.212D 2023A&A...674A.212D
de Burgos et al., Paper X 2024A&A...687A.228D 2024A&A...687A.228D
de Burgos et al., Paper XI 2024A&A...687L..16D 2024A&A...687L..16D
Negueruela et al., Paper XII 2024A&A...690A.176N 2024A&A...690A.176N
Martinez-Sebastian et al., Paper XIII 2025A&A...693L..10M 2025A&A...693L..10M
de Burgos et al., Paper XIV 2025A&A...695A..87D 2025A&A...695A..87D
(End) Gonzalo Holgado [IAC], Patricia Vannier [CDS] 25-Sep-2025