J/ApJS/281/38 RR Lyrae stars from Gaia DR3 and ZTF time series (Zhang+, 2025)
Classification for 969 double-mode RR Lyrae stars from Zwicky Transient
Facility.
Zhang J., Chen X., Wang S., Wang J., Deng L.
<Astrophys. J. Suppl. Ser., 281, 38 (2025)>
=2025ApJS..281...38Z 2025ApJS..281...38Z
ADC_Keywords: Stars, variable; Surveys; Optical; Photometry
Keywords: Periodic variable stars ; Double-mode variable stars ;
RR Lyrae variable stars ; RRd variable stars
Abstract:
RR Lyrae (RRL) variable stars are cornerstone distance indicators. In
particular, double-mode RR Lyrae (RRd) stars enable period-luminosity
relations (PLRs) that are less sensitive to metallicity, reducing
systematic biases in distance measurements. However, their utility has
been limited by a global sample of only ∼3000 objects. We develop an
automated RRd-screening pipeline and apply it to a crossmatched sample
between the Gaia DR3 RRL catalog and Zwicky Transient Facility (ZTF)
DR22 time-series photometry. The workflow combines Lomb-Scargle period
searches, iterative prewhitening, period-ratio constraints that
suppress ∼1 day sampling aliases, and amplitude-based quality cuts,
enabling large-scale RRd star screening. We produce two ZTF-based
catalogs: (i) 39,322 reliable single-mode RRL stars (40.5% of the
crossmatched set) and (ii) 969 RRd stars. Among the RRd stars, 614
objects are newly identified, substantially enlarging this previously
scarce sample; the catalog achieves an estimated completeness of
47.7%. The PLR derived from the newly discovered RRd stars agrees with
the LMC-based relation, though with larger uncertainties.
Incorporating these stars will help tighten the RRd PLR and improve
distance measurements. Looking ahead, systematic RRd searches with
upcoming surveys such as the Legacy Survey of Space and Time and the
China Space Station Telescope should further extend high-accuracy
distances across the Local Group and strengthen their cosmological
applications.
Description:
This study is based on the crossmatch between the 271,779 candidates
from the Gaia DR3 RR Lyrae variable star catalog and the Zwicky
Transient Facility (ZTF) DR22 photometric data.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 39322 RR Lyrae star catalog of ZTF
table2.dat 136 969 RRd star catalog of ZTF
table3.dat 91 46 Catalog of stars in the Gaia RRd sample with
potentially spurious secondary periods
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See also:
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
I/358 : Gaia DR3 Part 4. Variability (Gaia Collaboration, 2022)
J/AcA/64/177 : VI light curves of Gal. Bulge RR Lyrae (Soszynski+, 2014)
J/ApJS/219/25 : LCs of RR Lyrae stars in M3 (NGC5272) (Jurcsik+, 2015)
J/ApJ/807/127 : Properties of 70 RR Lyrae stars in LMC bar (Muraveva+, 2015)
J/MNRAS/487/5584 : First-overtone RR Lyrae stars from OGLE (Netzel+, 2019)
J/A+A/625/A14 : Reclassification of Cepheids in the Gaia DR2 (Ripepi+, 2019)
J/AcA/69/321 : OGLE RR Lyrae stars in Gal. bulge & disk (Soszynski+, 2019)
J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)
J/MNRAS/513/1958 : Study of RR Lyrae stars in MW substructures (Wang+, 2022)
J/other/NatAs/7.1081 : Double-mode RR Lyrae stars data (Chen+, 2023)
J/A+A/674/A18 : Gaia DR3. The RR Lyrae sample (Clementini+, 2023)
J/A+A/677/A177 : EPA K2 first-overtone RR Lyrae analysis (Netzel+, 2023)
http://www.ztf.caltech.edu/ : The Zwicky Transient Facility (ZTF) homepage
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID [1/271742] Internal ID number
8- 26 I19 --- Gaia Gaia DR3 source identifier [source_id]
28- 36 F9.7 d Per [0.2/1] Derived period
38- 43 F6.1 [-] logFAP [-319.1/-5]? log, false alarm probability
45- 53 F9.5 deg RAdeg Right Ascension, ZTF (J2000)
55- 63 F9.5 deg DEdeg [-30.5/88] Declination, ZTF (J2000)
65- 70 F6.3 mag rmag [11.8/21.6] ZTF r-band AB magnitude, mean
72- 76 F5.3 mag Amp [0.003/1] Amplitude
78- 82 F5.3 mag e_rmag [0.007/0.22] standard deviation in rmag
84- 88 I5 --- Nobs [42/17044] Number of observations
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID [7/271734] Internal ID number
8- 26 I19 --- Gaia Gaia DR3 source identifier [source_id]
28- 36 F9.7 d Per1 [0.29/0.6] Primary pulsation period
38- 42 F5.3 mag Amp1 [0.07/0.4] Primary pulsation light-curve
amplitude
44- 49 F6.1 --- logFAP1 [-319/-8.7]? Log, false alarm probability, Per1
51- 59 F9.7 d Per2 [0.3/0.6] Second pulsation period
61- 65 F5.3 mag Amp2 [0.012/0.22] Second pulsation light-curve
amplitude
67- 72 F6.1 --- logFAP2 [-315.1/-5.1]? Log, false alarm probability,
Per2
74- 80 F7.5 --- ratio [0.72/0.75] Period ratio, P1O/Pf (1)
82- 90 F9.7 d Per3 [0.12/6]?=0 Third pulsation period, see
Section 3.3
92- 97 F6.3 mag Amp3 [0.009/26]?=0 Third pulsation light-curve
amplitude
99- 107 F9.5 deg RAdeg Right Ascension, ZTF (J2000)
109- 117 F9.5 deg DEdeg [-28/85] Declination, ZTF (J2000)
119- 124 F6.3 mag rmag [13/20.4] ZTF r-band AB magnitude, mean
126- 130 F5.3 mag e_rmag [0.009/0.2] Standard deviation in rmag
132- 136 I5 --- Nobs [98/10137] Number of observations
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Note (1): Ratio, first-overtone to fundamental-mode period; See Section 3.1
for relationships between Per1, Per2, P1O, and Pf.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- Gaia Gaia DR3 source identifier [source_id]
21- 29 F9.5 deg RAdeg [8.4/358] Right Ascension, ZTF (J2000)
31- 39 F9.5 deg DEdeg [-27.8/74.8] Declination, ZTF (J2000)
41- 49 F9.7 d Pztf [0.35/0.62] Primary period, ZTF, this work
51- 59 F9.7 d Pf-Gaia [0.4/0.62] Fundamental period, Gaia DR3
61- 69 F9.7 d P1O-Gaia [0.31/0.46] First-overtone period, Gaia DR3
71- 76 F6.3 mag rmag [14.22/20.22] ZTF r-band AB magnitude, mean
78- 86 F9.7 d Pasassn [0.33/0.62]? ASAS-SN periods (1)
88- 91 A4 --- Type ? ASAS-SN type (RRAB, RRC or RRD) (1)
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Note (1): Jayasinghe+ (2018, II/366; 2019MNRAS.486.1907J 2019MNRAS.486.1907J, 2021MNRAS.503..200J 2021MNRAS.503..200J)
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 25-Jun-2026