J/A+A/701/A263 Gaia and K2 rotation of young solar-type stars (Breton+, 2025)
Rotation of young solar-type stars as seen by Gaia and K2.
Breton S.N., Distefano E., Lanzafame A.C, Palakkatharappil D.B.
<Astron. Astrophys. 701, A263 (2025)>
=2025A&A...701A.263B 2025A&A...701A.263B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, G-type ; Stars, activity ; Optical
Keywords: stars: activity - stars: rotation - stars: solar-type - starspots
Abstract:
Accurate surface rotation measurements are crucial to estimate stellar
ages and improve our understanding of stellar rotational evolution.
Comparisons of datasets obtained from different space missions on
common targets represent in this sense a way to explore the respective
biases and reliability of the considered instruments, as well as a
possibility to perform a more in-depth investigation of the properties
of the observed stars. In this perspective, we aim at using
observations for the K2 mission to provide an external validation to
Gaia rotation measurements, and confront observables available from
Gaia, K2, and Kepler. We therefore crossmatch the Gaia rotation
catalogue and the K2 mission Ecliptic Plane Input Catalogue (EPIC) in
order to find Gaia stars with both measured rotation and periods and
available K2 light curves. Using our crossmatch, we analyse 1063 light
curves from the K2 mission in order to characterise stellar rotational
modulations and compare the recovered periods with Gaia reference
values. The K2/Gaia cross-validated sample is used as a random-forest
classifier training set to identify a subsample of Gaia stars with
similar properties. We validate the Gaia rotation measurements for a
large fraction of the sample and we discuss the possible origin of the
discrepancies between some K2 and Gaia measurements. We note that the
K2 sample does not include members of the low-activity
ultra-fast-rotating (UFR) population that was highlighted by Gaia
observations, a feature that we explain considering the instrumental
capabilities of K2. Placing our sample in perspective with the full
Gaia rotation catalogues and Kepler observations, we show that the
population for which both Gaia and K2 are able to measure rotation is
composed of young late-type stars, a significant fraction of which is
not yet converged on the slow-rotator gyrochronological sequence. In
order to identify additional targets that have properties similar to
the cross- validated K2 sample (considering in particular rotation and
activity index), we compute the Local Outlier Factor (LOF) of the
stars in the Gaia DR3 rotation catalogue, considering the K2 stars as
reference, and we identify 40,423 stars with a high degree of
similarity, which can be useful for future statistical studies. To the
purpose of characterising the properties of young solar-type fast
rotators, future photometric spaceborne missions such as PLATO will
greatly benefit from the synergies with Gaia observations that we
illustrate in this work.
Description:
Surface rotation and activity parameters measured from K2 photometric
light curves for 744 targets observed by both K2 and Gaia. Local
Outlier Factor (LOF) with respects to this subsamplefor Gaia DR3 stars
with measured rotation in Distefano et al. (2023A&A...674A..20D 2023A&A...674A..20D).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 150 473594 Properties of the stars in the Gaia DR3
catalogue and their LOF
tabled1.dat 227 744 Properties of the K2 stars studied in thia work
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See also:
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 source identifier (dr3sourceid)
21- 30 F10.7 mag Gmag G-band mean magnitude from Gaia DR3
(photgmean_mag)
32- 53 F22.19 mag Bp-RpCorr BP-RP from Gaia DR3, corrected using the
ebpminrp_gspphot from Gaia DR3 Apsis
catalogue (bprpcorr)
55- 62 F8.4 mag GMAG ? Absolute magnitude from Gaia DR3 Apsis
GSP-Phot Aeneas best library using BP/RP
spectra (mg_gspphot)
64- 82 F19.16 d Prot Gaia DR3 best rotation period from Distefano
et al. (2023A&A...674A..20D 2023A&A...674A..20D)
(bestrotationperiod)
84- 97 E14.13 d e_Prot Gaia DR3 best rotation period uncertainty from
Distefano et al. (2023A&A...674A..20D 2023A&A...674A..20D)
(bestrotationperiod_error)
99-110 F12.10 mag AIG Gaia DR3 G band activity index from Distefano
et al. (2023A&A...674A..20D 2023A&A...674A..20D)
(maxactivityindex_g)
112-130 F19.16 --- logrIRT ? Chromospheric activity index computed after
Lanzafame et al. (2023A&A...674A..30L 2023A&A...674A..30L)
(logrirt)
132-150 F19.16 --- LOF Local outlier factor computed using as
reference the stars of Table D1 (lof)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tabled1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 I9 --- EPIC K2 EPIC identifier (epic)
11- 29 I19 --- GaiaDR2 Gaia DR2 source identifier (dr2sourceid)
31- 49 I19 --- GaiaDR3 Gaia DR3 source identifier (dr3sourceid)
51- 60 F10.7 mag Gmag G-band mean magnitude from Gaia DR2 or DR3
(photgmean_mag)
62- 80 F19.16 mag Bp-RpCorr ? BP-RP from Gaia DR3, corrected using the
ebpminrp_gspphot from Gaia DR3 Apsis
catalogue (bprpcorr)
82- 89 F8.4 mag GMAG ? Absolute magnitude from Gaia DR3 Apsis
GSP-Phot Aeneas best library using
BP/RP spectra (mg_gspphot)
91-109 F19.16 d Prot Surface rotation period measured from
photometric modulations in K2 light curves
(final_prot)
111-130 F20.16 d e_Prot ?=-1 Surface rotation period uncertainty
(efinalprot)
132 I1 --- Flag [0/1] Flag for K2 measurements consistent with
Gaia values (flag_consistence) (1)
134-152 F19.13 ppm Sph Sph photometric activity index (sph)
154-174 F21.15 ppm e_Sph Sph photometric activity index uncertainty
(e_sph)
176-194 F19.16 --- logrIRT ? Chromospheric activity index computed after
Lanzafame et al. (2023A&A...674A..30L 2023A&A...674A..30L)
(logrirt)
196-217 F22.19 --- corrCoef Mean correlation coefficient between Gaia
photometric band computed from Distefano et
al. (2023A&A...674A..20D 2023A&A...674A..20D)
(meancorrelationcoefficient)
219-227 A9 --- Cluster ? Cluster appartenance of the target (Cluster)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
1 = K2 measurements are consistent with Gaia values from Lanzafame et al.
(2018A&A...616A..16L 2018A&A...616A..16L) and Distefano et al. (2023A&A...674A..20D 2023A&A...674A..20D)
0 = otherwise
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Acknowledgements:
Sylvain Breton, sylvain.breton(at)inaf.it
References:
Lanzafame et al., 2018A&A...616A..16L 2018A&A...616A..16L
Gaia Data Release 2. Rotational modulation in late-type dwarfs
Vallenari et al., 2023A&A...674A...1G 2023A&A...674A...1G
Gaia Data Release 3. Summary of the content and survey properties
Distefano et al., 2023A&A...674A..20D 2023A&A...674A..20D
Gaia Data Release 3. Rotational modulation and patterns
of colour variation in solar-like variables
Creevey et al., 2023A&A...674A..26C 2023A&A...674A..26C
Gaia Data Release 3. Astrophysical parameters inference system (Apsis).
I. Methods and content overview
Lanzafame et al., 2023A&A...674A..30L 2023A&A...674A..30L
Gaia Data Release 3. Stellar chromospheric activity and mass accretion
from Ca II IRT observed by the Radial Velocity Spectrometer
https://gea.esac.esa.int/archive/documentation/GDR3/index.html
Gaia DR3 online documentation
(End) Patricia Vannier [CDS] 05-Aug-2025