Flares in hot subdwarf & WDs from TESS photometry Virtual Observatory Resource

Authors
  1. Xing K.
  2. Zong W.
  3. Silvotti R.
  4. Fu J.-N.
  5. Charpinet S.
  6. Cang T.,Hermes J.J.
  7. Ma X.-Y.
  8. Wang H.
  9. Wang X.
  10. Wu T.
  11. Wang J.
  12. Published by
    CDS
Abstract

Stellar flares are critical phenomena on stellar surfaces, which are closely tied to stellar magnetism. While extensively studied in main-sequence (MS) stars, their occurrence in evolved compact stars, specifically hot subdwarfs and white dwarfs (WDs), remains scarcely explored. Based on Cycles 1-5 of TESS photometry, we conducted a pioneering survey of flare events in ~12000 compact stars, corresponding to ~38000 light curves with a 2 minute cadence. Through dedicated techniques for detrending light curves, identifying preliminary flare candidates, and validating them via machine learning, we established a catalog of 1016 flares from 193 compact stars, including 182 from 58 sdB/sdO stars and 834 from 135 WDs, respectively. However, all flaring compact stars showed signs of contamination from nearby objects or companion stars, preventing sole attribution of the detected flares. For WDs, it is highly probable that the flares originated from their cool MS companions. In contrast, the higher luminosities of sdB/sdO stars diminish companion contributions, suggesting that detected flares originated from sdB/sdO stars themselves or through close magnetic interactions with companions. Focusing on a refined sample of 23 flares from 13 sdB/sdO stars, we found their flare frequency distributions were slightly divergent from those of cool MS stars; instead, they resemble those of hot B/A-type MS stars having radiative envelopes. This similarity implies that the flares on sdB/sdO stars, if these flares did originate from them, may share underlying mechanisms with hot MS stars, which warrants further investigation.

Keywords
  1. stellar-flares
  2. white-dwarf-stars
  3. subdwarf-stars
  4. photometry
  5. visible-astronomy
Bibliographic source Bibcode
2024ApJS..271...57X
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/271/57
IVOA Identifier IVOID
ivo://CDS.VizieR/J/ApJS/271/57

Access

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http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/271/57
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/271/57
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/271/57
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Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
http://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/271/57/table4?
https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/271/57/table4?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/271/57/table4?

History

2024-08-01T09:15:29Z
Resource record created
2024-08-01T08:27:07Z
Updated
2024-08-01T09:15:29Z
Created

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr