J/A+A/693/A268 Hot sub-luminous and binaries variability (Ranaivomanana+, 2025)
Variability of hot sub-luminous stars and binaries:
Machine learning analysis of Gaia DR3 multi-epoch photometry.
Ranaivomanana P., Uzundag M., Johnston C., Groot P.J., Kupfer T., Aerts C.
<Astron. Astrophys. 693, A268 (2025)>
=2025A&A...693A.268R 2025A&A...693A.268R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Stars, subdwarf ; Binaries, orbits ; Optical
Keywords: methods: data analysis - methods: statistical -
techniques: photometric - surveys - subdwarfs -
stars: variables: general
Abstract:
Hot sub-luminous stars represent a population of stripped and evolved
red giants located at the Extreme Horizontal Branch (EHB). Since they
exhibit a wide range of variability due to pulsations or binary
interactions, unveiling their intrinsic and extrinsic variability is
crucial for understanding the physical processes responsible for their
formation. In the Hertzsprung-Russell diagram, they overlap with
interacting binaries such as Cataclysmic Variables (CVs). By
leveraging cutting-edge clustering algorithm tools, we investigate the
variability of 1,576 hot subdwarf variable candidates using
comprehensive data from Gaia DR3 multi-epoch photometry and Transiting
Exoplanet Survey Satellite (TESS) observations. We present a novel
approach that utilises the t-distributed stochastic neighbor embedding
(t-SNE) and the Uniform Manifold Approximation and Projection (UMAP)
dimensionality reduction algorithms to facilitate the identification
and classification of different populations of variable hot subdwarfs
and Cataclysmic Variables in a large dataset. In addition to the
publicly available Gaia time-series statistics table, we adopt extra
statistical features that enhance the performance of the algorithms.
The clustering results lead to the identification of 85 new hot
subdwarf variables based on Gaia and TESS lightcurves and 108 new
variables based on Gaia lightcurves alone, including reflection-effect
systems, HW Vir, ellipsoidal variables, and high-amplitude pulsating
variables. A significant number of known Cataclysmic Variables (140)
distinctively cluster in the 2-D feature space among an additional 152
objects that we consider new Cataclysmic Variable candidates. This
study paves the way for more efficient and comprehensive analyses of
stellar variability from both ground and space-based observations, as
well as the application of machine learning classifications of
variable star candidates in large surveys.
Description:
Catalogue consisting of new and previously known variables identified
from 1576 candidate and known hot subdwarfs. The variability type
classification is based on Gaia light curves and, where available,
confirmed by TESS light curves for identified variable hot subdwarfs.
For cataclysmic variables (CVs), the classification relies on existing
classifications from the literature. New CV candidates are presented
for objects in Cluster 2 that have no matches in the literature.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea4.dat 91 63 Variability of 63 confirmed hot subdwarfs
identified from Gaia and TESS
tablea5.dat 93 78 Variability of 78 candidate hot subdwarfs
identified from Gaia and TESS
tablea6.dat 76 134 New variables (134) identified from candidate
hot subdwarfs with Gaia lightcurves alone
tablea7.dat 76 15 New variables (15) identified from known
hot subdwarfs with Gaia lightcurves alone
tablea8.dat 83 140 List of 140 known CVs from Cluster 2
tablea9.dat 57 152 List of 152 candidate CVs from Cluster 2
identified in this work
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: tablea4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 source ID
21- 29 F9.5 deg RAdeg Right Ascension (ICRS) at Ep=2016.0
31- 39 F9.5 deg DEdeg Declination (ICRS) at Ep=2016.0
41- 49 F9.6 d PerG Gaia G-band period
51- 57 E7.2 10-2d e_PerG Gaia G-band period uncertainty
59- 67 F9.6 d PerT TESS period
69- 75 E7.2 10-2d e_PerT TESS period uncertainty
77- 88 A12 --- Type Variability type
90- 91 A2 --- Ref Reference (G1)
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Byte-by-byte Description of file: tablea5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 source ID
21- 29 F9.5 deg RAdeg Right Ascension (ICRS) at Ep=2016.0
31- 39 F9.5 deg DEdeg Declination (ICRS) at Ep=2016.0
41- 49 F9.6 d PerG Gaia G-band period
51- 57 E7.2 10-2d e_PerG Gaia G-band period uncertainty
59- 68 F10.6 d PerT TESS period
70- 76 E7.2 10-2d e_PerT TESS period uncertainty
78- 90 A13 --- Type Variability type
92- 93 A2 --- Ref Reference (g1)
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Byte-by-byte Description of file: tablea6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 source ID
21- 29 F9.5 deg RAdeg Right Ascension (ICRS) at Ep=2016.0
31- 39 F9.5 deg DEdeg Declination (ICRS) at Ep=2016.0
41- 50 F10.6 d PerG Gaia G-band period
52- 58 E7.2 10-2d e_PerG Gaia G-band period uncertainty
60- 76 A17 --- Type Variability type
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Byte-by-byte Description of file: tablea7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 source ID
21- 29 F9.5 deg RAdeg Right Ascension (ICRS) at Ep=2016.0
31- 39 F9.5 deg DEdeg Declination (ICRS) at Ep=2016.0
41- 49 F9.6 d PerG Gaia G-band period
51- 57 E7.2 10-2d e_PerG Gaia G-band period uncertainty
59- 74 A16 --- Type Variability type
76 A1 --- Ref Reference (G1)
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Byte-by-byte Description of file: tablea8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 source ID
21- 29 F9.5 deg RAdeg Right Ascension (ICRS) at Ep=2016.0
31- 39 F9.5 deg DEdeg Declination (ICRS) at Ep=2016.0
41- 48 F8.6 d PerT ?=- TESS period
50- 57 F8.6 10-2d e_PerT ?=- TESS period uncertainty
59- 66 F8.6 d Porb ?=- Orbital period from the literature
68- 81 A14 --- Type CV type
83 A1 --- Ref Reference (G1)
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Byte-by-byte Description of file: tablea9.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 source ID
21- 29 F9.5 deg RAdeg Right Ascension (ICRS) at Ep=2016.0
31- 39 F9.5 deg DEdeg Declination (ICRS) at Ep=2016.0
41- 48 F8.6 d PerT ?=- TESS period
50- 57 E8.6 10-2d e_PerT ?=- TESS period uncertainty
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Global notes:
Note (G1): References as follows:
2 = Uzundag at al., 2024A&A...684A.118U 2024A&A...684A.118U
3 = Schaffenroth et al., 2019A&A...630A..80S 2019A&A...630A..80S
4 = Barlow et al., 2022ApJ...928...20B 2022ApJ...928...20B
5 = Canbay et al., 2023AJ....165..163C 2023AJ....165..163C
6 = hou et al., 2023AJ....165..148H 2023AJ....165..148H
7 = Culpan et al., 2022A&A...662A..40C 2022A&A...662A..40C
8 = Geier et al., 2017A&A...600A..50G 2017A&A...600A..50G
9 = Krzesinski et al. (in prep)
TW = This Work
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Acknowledgements:
Princy Ranaivomanana, rtprincy(at)gmail.com
(End) Patricia Vannier [CDS] 06-Dec-2024