J/A+A/703/A240 PU learning of hybrid pulsators in TESS (Kliapets+, 2025)
Automated all-sky detection of gamma Doradus/delta Scuti Hybrids in
TESS data from positive unlabelled (PU) learning.
Kliapets M., Huijse P., Tkachenko A., Kemp A., Fritzewski D.J., Hey D.,
Aerts C.
<Astron. Astrophys. 703, A240 (2025)>
=2025A&A...703A.240K 2025A&A...703A.240K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Asteroseismology ; Optical
Keywords: asteroseismology - methods: data analysis - methods: statistical -
stars: variables: delta Scuti
Abstract:
The Transiting Exoplanet Survey Satellite (TESS) mission has observed
hundreds of millions of stars, substantially contributing to the
available pool of high-precision photometric space data. Among them
are the relatively rare gamma Doradus/delta Scuti (gamma Dor/delta
Sct) hybrid pulsators, which have been previously studied using Kepler
data. These stars are perfect laboratories to probe both inner and
outer interior stellar layers thanks to them exhibiting both pressure
and gravity modes.
We seek to classify an all-sky sample of AF stars observed by TESS to
find previously undiscovered hybrid pulsators and supply them in a
catalogue of candidates. We also aim to compare the light curves
produced with the TESS-Gaia Light Curve (TGLC) pipeline, currently
underused in variability studies, with other publicly available light
curves.
We compared dominant and secondary frequencies of confirmed hybrid
pulsators in Kepler, extended mission Quick Look Pipeline (QLP) data,
and nominal and extended mission TGLC data. We then used a
feature-based positive unlabelled (PU) learning classifier to search
for new hybrid pulsators amongst TESS AF stars and investigated the
properties of the detected populations.
We find that the variability of confirmed hybrids in TGLC agrees well
with the one occurring in QLP light curves and has a high recovery
rate of Kepler-extracted frequencies. Our "smart binning" method
allows for robust extraction of hybrids from large unlabelled
datasets, with an average out-of-bag prediction for test set hybrids
at 93.04%. The analysis of dominant frequencies in high-probability
candidates shows that we find more pressure-mode dominant hybrids. Our
catalogue includes 62 026 new candidate light curves from the nominal
and extended TESS missions, with individual probabilities of being a
hybrid in each available sector.
Description:
We classified an all-sky sample of AF stars observed by TESS to find
hybrid pulsators and supply them in a catalogue of candidate hybrids.
We used an unsupervised (Positive Unlabelled Learning) classifier with
featured based on our 'smart binning' methodology, leveraging known
hybrids and structure in the unlabelled data. The analysis of dominant
frequencies in high-probability candidates shows that we find more
pressure-mode dominant hybrids. Our catalogue includes 62,026 new
candidate light curves from the nominal and extended TESS missions,
with individual probabilities of being a hybrid in each available
sector. We additionally supply catalogues of p- and g-mode pulsator
candidates.
Note that this catalogue contains candidate, non-confirmed pulsators.
We note contamination from multi-periodic variables such as rotational
variables with p-modes and eclipsing binaries -- a method to clean the
sample will be available in the follow-up publication (Kliapets et
al., in prep.).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 384 62487 Hybrib mode pulsator candidates
table2.dat 274 44591 p-mode pulsator candidates
table3.dat 277 25501 g-mode pulsator candidates
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See also:
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
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- 10 I10 --- TIC TESS Input Catalog ID
12- 30 I19 --- GaiaDR3 Gaia DR3 source ID
32- 51 F20.16 deg RAdeg Right ascension (ICRS) at Ep=2016.0
53- 72 F20.16 deg DEdeg Declination (ICRS) at Ep=2016.0
74- 75 I2 --- Sector TESS observing sector
77- 94 F18.16 c/d Freqlow Dominant frequency <4c/d
96-119 E24.16 c/d e_Freqlow Error of Freqlow
121-138 F18.16 % Amplow Amplitude of freq_low
140-163 E24.16 % e_Amplow Error of Amplow
165-183 F19.16 c/d Freqhigh Dominant frequency >4c/d
185-208 E24.16 c/d e_Freqhigh Error of Freqhigh
210-227 F18.16 % Amphigh Amplitude of dominant frequency
229-252 E24.16 % e_Amphigh Error of Amphigh
254-263 F10.4 K Teff Effective temperature
265-278 F14.9 K e_Teff Error of Teff
280-299 F20.16 Rsun Rad Stellar radius
301-318 F18.16 Rsun e_Rad Error of Rad
320-342 F23.16 Lsun Lum Stellar luminosity
344-365 F22.16 Lsun e_Lum Error of Lum
367-384 F18.16 --- Prob Probability of being a hybrid
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 I10 --- TIC TESS Input Catalog ID
12- 30 I19 --- GaiaDR3 Gaia DR3 source ID
32- 51 F20.16 deg RAdeg Right ascension (ICRS) at Ep=2016.0
53- 72 F20.16 deg DEdeg Declination (ICRS) at Ep=2016.0
74- 75 I2 --- Sector TESS observing sector
77- 95 F19.16 c/d Freqhigh Dominant frequency >4c/d
97-120 E24.16 c/d e_Freqhigh Error of Freqhigh
122-139 F18.16 % Amphigh Amplitude of Freqhigh
141-164 E24.16 % e_Amphigh Error of Amphigh
166-175 F10.4 K Teff Effective temperature
177-190 F14.9 K e_Teff Error of Teff
192-210 F19.16 Rsun Rad Stellar radius
212-229 F18.16 Rsun e_Rad Error of Rad
231-252 F22.16 Lsun Lum Stellar luminosity
254-274 F21.16 Lsun e_Lum Error of Lum
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 I10 --- TIC TESS Input Catalog ID
12- 30 I19 --- GaiaDR3 Gaia DR3 source ID
32- 51 F20.16 deg RAdeg Right ascension (ICRS) at Ep=2016.0
53- 72 F20.16 deg DEdeg Declination (ICRS) at Ep=2016.0
74- 75 I2 --- Sector TESS observing sector
77- 94 F18.16 c/d Freqlow Dominant frequency <4c/d
96-119 E24.16 c/d e_Freqlow Error of Freqlow
121-138 F18.16 % Amplow Amplitude of Freqlow
140-163 E24.16 % e_Amplow Error of Amplow
165-174 F10.4 K Teff Effective temperature
176-189 F14.9 K e_Teff Error of Teff
191-210 F20.16 Rsun Rad Stellar radius
212-230 F19.16 Rsun e_Rad Error of Rad
232-254 F23.16 Lsun Lum Stellar luminosity
256-277 F22.16 Lsun e_Lum Error of Lum
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Acknowledgements:
Mykyta Kliapets, mykyta.kliapets(at)kuleuven.be
(End) Patricia Vannier [CDS] 23-Sep-2025