J/A+A/690/A295 Nearby RR Lyrae stars RV and VK photometry (Zgirski+, 2024)
The infrared surface brightness technique applied to RR Lyrae stars from the
solar neighborhood.
Zgirski B., Gieren W., PietrzyNski G., Gorski M., Wielgorski P., Storm J.,
Bras G., Kervella P., Nardetto N., Hajdu G., Chini R., Haas M.
<Astron. Astrophys. 690, A295 (2024)>
=2024A&A...690A.295Z 2024A&A...690A.295Z (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Stars, variable ; Radial velocities ;
Photometry, infrared ; Optical
Keywords: stars: distances - stars: oscillations - stars: variables: RR Lyrae -
infrared: stars
Abstract:
The Baade-Wesselink method, also known as the pulsation parallax
method allows us to estimate distances to individual
pulsating stars. Accurate geometric parallaxes obtained by the Gaia
mission serve us in the calibration of the method and in the
determination of its precision. The method also provides a way of
determining mean radii of pulsating stars.
The main aim of this work is to determine the scatter and possible
dependence of p-factors of RR Lyrae stars on their pulsation periods.
The secondary objective is to determine mean radius - period relations
for these stars.
Our calibrations for RR Lyrae stars are based on photometric data
gathered at the Cerro Murphy Observatory and parallaxes from the Data
Release 3 of the Gaia space mission. We obtained spectroscopic data
specifically for this project using high resolution spectrographs. We
use the Infrared Surface Brightness (IRSB) version of the method that
relies on a surface brightness - color relation dependent on the (V-K)
color. It allows us to estimate stellar angular diameters while
variations of the stellar radius are being traced using measurements
of the stellar radial velocity obtained from spectroscopy. We present
results based on four different empirical surface brightness-color
relations - three of them being relations for dwarfs and subgiants and
one for classical Cepheids.
We present our calibration of projection factors and determination of
the mean radii for nine Galactic RR Lyrae stars. We obtain the spread
of p-factors of around 0.07-0.08 for our sample of RR Lyrae stars from
the solar neighborhood. However, depending on a SBCR, we also find
relations between the p-factor and the pulsation period for RRab stars
with the rms scatter around the relation of around 0.05, but with
relatively large uncertainty of relations' parameters. We present
relations between the mean radius and period for RR Lyrae pulsating in
the fundamental mode with the rms scatter around the relation of 0.012
solar radii . We observe a clear offset between p-factors obtained
using the IRSB technique (with mean p between 1.39 and 1.45) and
values inferred using the SPIPS tool. It confirms that different
implementations of the Baade-Wesselink method are sensitive to various
components of the p- factor. On the other hand, we obtain a similar
scatter of p of as observed in a previous study based on the SPIPS
tool. Our period-radius relations are in a good agreement with both
the inference based on SPIPS and theoretical predictions.
Description:
The catalog contains radial velocities (RV) and near-infrared K- band
and optical V- band photometry gathered for the purpose of
determinations of p-factors for RR Lyrae stars from the solar
neighborhood.
We measured the RVs based on the high-resolution spectra obtained with
CORALIE (Queloz et al., 2000A&A...354...99Q 2000A&A...354...99Q), HARPS (Mayor et al.,
2003Msngr.114...20M 2003Msngr.114...20M), UVES (Dekker et al., 2000, SPIE, 4008, 534) and
FEROS (Kaufer et al., 1999Msngr..95....8K 1999Msngr..95....8K) using the RaveSpan tool
(Pilecki et al., 2012, IAUS, 282, 301).
We obtained photometric data at the Cerro Murphy Observatory (OCM)
using 0.4m VYSOS-16 (Reipurth et al., 2004AN....325..671R 2004AN....325..671R) and 0.8m
IRIS (Hodapp et al., 2010, SPIE, 7735, 1, Watermann 2012,
'Automatisierte Variabilitaetsmessungen im Visuellen und
Infraroten', PhD dissertation (in German), Fakultaet fuer Physik und
Astronomie der Ruhr-Universitaet Bochum) instruments. We performed the
photometric measurements using our custom pipeline based on Astropy
(Astropy Collaboration, 2013A&A...558A..33A 2013A&A...558A..33A) and DAOPHOT (Stetson,
1987PASP...99..191S 1987PASP...99..191S).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 44 9 List of studied RR Lyrae stars
table7.dat 35 215 Radial velocity measurements
table8.dat 37 226 Optical V-band photometric measurements
table9.dat 37 271 Near-infrared K-band photometric measurements
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See also:
J/ApJ/914/10 : Field RR Lyrae as Gal. probes. III. Abundances (Crestani+, 2021)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Object name
12- 13 I2 h RAh Simbad right ascension (J2000)
15- 16 I2 min RAm Simbad right ascension (J2000)
18- 22 F5.2 s RAs Simbad right ascension (J2000)
24 A1 --- DE- Simbad declination sign (J2000)
25- 26 I2 deg DEd Simbad declination (J2000)
28- 29 I2 arcmin DEm Simbad declination (J2000)
31- 34 F4.1 arcsec DEs Simbad declination (J2000)
36- 44 F9.7 d Per Period from Crestani et al.
(2021ApJ...914...10C 2021ApJ...914...10C, Cat. J/ApJ/914/10)
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Object name
10- 22 F13.5 d HJD Heliocentric Julian Date of the observation
25- 30 F6.2 km/s RV Radial Velocity
32- 35 F4.2 km/s e_RV Uncertainty of the radial velocity measurement
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Object name
10- 22 F13.5 d HJD Heliocentric Julian Date of the observation
24- 30 F7.4 mag Vmag V-band aperture magnitude in the
Johnson-Kron-Cousins system (1)
32- 37 F6.4 mag e_Vmag Uncertainty of the V-band magnitude
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Note (1): Standardization performed using magnitudes of comparison stars from
the Gaia synthetic photometry catalog (Gaia Collaboration,
2023A&A...674A..33G 2023A&A...674A..33G, Cat. J/A+A/674/A33)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Object name
10- 22 F13.5 d HJD Heliocentric Julian Date of the observation
24- 30 F7.4 mag Kmag K-band aperture magnitude in the 2MASS system (1)
32- 37 F6.4 mag e_Kmag Uncertainty of the K- band magnitude
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Note (1): Standardization performed using magnitudes of comparison stars from
the catalog of Cutri et al. (2003, Cat. II/246)
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Acknowledgements:
Bartlomiej Zgirski, bzgirski(at)astro-udec.cl
(End) Bartlomiej Zgirski [Concepcion Univ.], Patricia Vannier [CDS] 28-Aug-2024